Burning Paper Tutorial Using Houdini & Karma

hello everyone and welcome to rev away my name is savage jalassi and in this video i'm going to be showing you how to create this burning paper effects thank you so much for joining us and i hope you'll find this video informative and useful let's get started so let's talk about what we're going to learn today and this is the effects preview again and the final result is done using houdini 19 and karma so we're going to cover that and as you can see the effect is basically a fire burning away paper but it's not just any fire there's a lot of uh interesting things happening here so the first thing is the propagation effect you can see we have a couple of places that starts off burning and then that fire propagates now it's not just a growing propagation the parts that have burned or are eaten away they're not gonna burn again so it's uh it knows what's has been eaten and what's remaining and that's going to be done using a a sub solver and the power spreads tool to basically create this propagation mask that mask then we're going to isolate it and find the area where the fire is going to come from and use that to create the fire simulation i'm not super happy with the final result but i will show you what tweaks needs to be done to make it look more interesting mainly what i don't like here is the amount of smoke and how it's affecting the the fire behavior but overall as the in terms of flames i think the flames are good we just need to reduce the smoke and that can be done uh easily now this may look simple but actually it's quite complicated took it to get the paper the geometry deforming as well as being used in other sims so there's like a a recursive system that is changing the geometry but also that end result is being used in other processes so the main effects that is quite complex here is the deformation of the paper you can see as the fire propagates the remaining paper ash like is different it has a different noise it has a different texture so we added this complex cool effects where the paper that's been not eaten away yet but about to get burned out it starts to crumble in the form and as you can see the edges of this paper are actually shrinking and so the effects is not limited to where the fire is we wanted to create the that effect where if you have a thick paper that have maybe different materials like a layer of plastic and you go through a heating process and it starts burning that heat will actually deform the entire paper and and try to get it to shrink and crumble and that's the complex part that's happening here you can see that effect here you can see the edges are being pulled but there is nothing on them there's no fire reached out to them yet so and then you can see it here happening quite well and this deformation is actually going to be again the end result is always going to be used as a fire source and layering all these effects together it needs to happen in specific orders otherwise we won't get the uh the final result and it won't look correct so basically we have this crumbling at the center where the fire has already gone through and then we have other parts that have not been touched by fire but they are also behaving uh to that fire and reacting so that's something we're going to cover you can see the end result here is quite cool with all the crumbling and and deformation all right so let me show a detailed list of what we're going to cover so the burning paper using houdini and karma i'm going to talk about the geometry preparation i'll start off with something simple this is done using a mega scan asset parchment paper that has an actual alpha mask that i used i'm going to cover that and see how we can create a simple paper maybe just using noise i'm going to create the fire propagation we're going to create the paper crumbling effect and that's the propagation of the fire and what's left behind it how the paper would look like after the fire burn burns it away i'm going to create the source for the fire and the fire itself and then we're going to create the karma scene and prep the layout lighting and shading so here i have two chairs uh and uh the statue here this is i believe from a place called paulie haven so free free stuff and then the mega scan uh this is only free if you use it with unreal engine so you'd have to have a count to get this table but there's other assets from poly heaven that can be used to build something similar if you're interested in creating that uh also going to look at using glyph file format to import geometry and shaders into houdini how to work with poly heaven haven and import that into karma i'm going to talk about rendering and composing this in nuke and at the end i'm going to show how to create a cool cracking effect as the paper burns away and potentially turn it into ashes so we have everything that gets burned away will basically fall as particles that we can use other smoke sims on them if we wanted to but basically i wanted to turn this into ashes but the idea here is this paper is very thick and so it's not going to just fall it's still there is still residue in it and uh there's one more effects here you can see there's smoke coming from underneath the paper it's not super realistic at the moment but this is something you would get if there's a lot of heat and there's a lot of wind happening you would get this uh second layer of smoke white smoke from underneath the paper uh yeah so let's get started and see how this is can be done in houdini so let's take a look at the project it's not very complicated to be honest and let me delete this okay let's take a look at the first part which is the paper so this is what i have as a starting point and this is the geometry and the way i created this geometry is by using mega scan textures and let me show that so if you go to mega scan website and type in paper you will find something like this i believe this is the one this has a lot of noises at the edges but this is one of the textures and you would get you won't get geometry but you will get textures and this is the texture example so here i have the alpha or the opacity mask as this the this is the diffuse texture the albedo which i multiplied with a an existing texture map from the witcher 3 so i multiplied it over this and that's the final final albedo texture that i used and then i have a displacement so all this would you would find in the uh once you download the files and the displacement looks like this well not so much but yeah you get the displacement information so let's see how to import that well actually before that so you don't need all of this you don't need to use mega scan you can still google all paper alpha and use some of these like this one would give you a nice alpha this one you just have to mask it to get this nice edges and then it would just be a matter of creating some noise maybe using just a mountain node like this and mask it so that it only happens at the edges so maybe something like this and lower the roughness yeah so we can easily create a nice deformation and fake all of this we don't have to use the textures if you don't have mega skin so okay i applied the uh the opacity let's dive inside so a uh color map with the uv texture uh first of all i created a grid sorry and then a texture just a uv texture node promoted that into a point attribute here it's not going to matter because i needed its points and it's just a flat plane so it's going to be fine and then i use that uv texture to read in the opacity and also the displacement so the displacement information is being used to push the uh let me do this i'm gonna disconnect the this has the displacement map i'm gonna delete it and let me show you how it's done so color map node and this is the map and the uv coordinate so vector to float because the uv is two you can use a vector to float three that's fine and then the x would go to the u and the y would go to the v and let's take a look at this in as colors this node is locked so let me unlock it so the disk map is is not connected properly and let me do that yeah so that now the displacement map is being visualized they just copied the path and paste it here so this okay so i'm going to use this black and white information let me just play this splat shade i'm going to use this black and white information to offset the y position so set vector component and this is the vector i want to change one of its values i'm going to change the y-coordinate and this is the result i want to use the displacement and if i connect this to p now you see that all the paper has moved up and we got all this deformation all we have to do now is delete everything else outside the the mask and i'm using a very high resolution mesh so it's one million points and it's one thousand by 1000 i think it's very high but you can lower it if it if you find it slow so last delete anything that is not black that is black sorry and then i can use a uv quick shade node to display the texture and this is the result i have in the viewport cool so i then wanted to add extra deformation i felt the paper is quite flat and i didn't want that i want to make it feel thicker and heavier that where it can stand on its center and everything else is uh bent or deformed and not on on the surface and the reason i did this is that just wanted to have more gaps when it deformed the geometry it has space to go because it's if it's super flat and we deform it then it has to go up and it's not going to look great so this way it's going to be simpler so what i did is i put a bend node let me show how to do that so here is the bend node and i just want to make this more concave so let's say we're gonna bend it this way i'm going to copy the same note and do it in the other direction so the capture direction -1 and i'm going to lower it and then another bent let's do this here another bend node pointing in the x direction and let's increase the capture region and move this i just want to affect the segment from the the page from the paper sorry i'm gonna bend it up like that and if we wanted to hit one corner i'm gonna copy this one more time and just this is up let's scroll down so let's see yeah minus one and then this one is -1 as well and let's lower the value i just want to move it to this corner something like this and i'm going to lower the capture region and we can either go down or up let's increase the capture something like that so yeah we can get some nice deformation on this so it's not super flat and that's what i've done here not as much as the example we did all right so i think that's pretty much it for the pepper paper geometry preparation we're going to start talking about the the fire spread source and how to use the pyro source spread node in houdini next on the list is the fire propagation or fire spread so let me show that this is the final result of the fire propagation and we're basically selecting and telling it this is this place is super hot it's going to start burning and then the fire starts propagating from that so this is the final result from the source we can also create various masks for example can isolate the edge we can create something like this and that's what we use to make the color of the burn let's change it and can make another color here so that part is super bright and let's play it okay so let's take a look i'm gonna create a copy this grid and let's lower the resolution to 200 so it's faster to work with and let me make sure everything is hidden what's happening okay and let's create a group node and i'm gonna group a couple of points just a couple of points at one of the corners and i'm going to create a wrangle node and i'm going to create the spread node pyrospread source and this node what this this node is looking for is basically a temperature or a burn field so i'm going to create a temperature field a temperature value and i'm going to set it to 10. and this only is going to be true for the points that we just selected why is this not working oh attribute yeah it is correct why is this not working let's see oh cooking was interrupted yeah this happens a lot so when i hit when houdini is calculating something and i hit escape sometimes it doesn't like that yeah i think now it's back okay so group tool that's the points and those points have a value of 10 everything else has a value of zero so let's create a color node and let's use the visualize mode so i'm going to visualize temperature and you can see the areas that we just set value to 10 has different color and if i hit play it's not not much is happening right now so let's create a color node and this visualize the temperature after the solve gonna hide this and let's hit play no propagation happening let's lower the cooling rate and increase the search radius because maybe we don't have enough points and if i hit play now you can see the fire or the temperature still it's propagating nicely which is pretty cool so because the geometry may not have enough points what i'm going to do is i'm going to create a scatter nodes scatter node and just increase this to 10 maybe hundred thousand and fill this geometry with lots of points now we're gonna group let's group by bounding box and just group one corner like we did and let's go back to the first frame now if i hit play you can see the propagation is happening so we have simple options here let's increase the search radius and the next neighbor so the point can't look up further and finds more points easily and i'm going to add a noise to this well there's noise right now so i'm going to just lower the scale to 0.2 and let's hit play you can see the noise pattern is is different and let's increase the search radius at the rate to 5. yes you know it's moving faster and let's increase the search radius and set this to 10 and this to 0.6 so let's hit play and see yeah it's working so we can what we can do is we can copy this node again and create another source here and let's so and when i copy this node i'm going to set instead of initial merge replace i'm going to say union with existing so if i hit play they're both propagating and meeting at the center and that's our source so we can use the temperature as a mask to isolate the edge and that's the part we're going to use to emit fire from so the fire source is going to be only the edge and then the the remaining masks we're going to use to basically transition to other geometries or the deformed geometry so once the mask is gone once the plate the the spread happens everything else behind it is gonna become black and we can always lower this to get nice gradients maybe this 2.5 and i will show it in here so the next uh tricky part so the next tricky part is to create this source dynamically because right now he's just selected two and the simplest way to do that is by scattering one point at the geometry so i'm gonna scatter one point and i'm gonna change it every frame okay so it changes every 10 frames and if i look at that point scattered on the geometry one time it's there let's see so that's one every 10 frames it changes and uh i'm going to add a a p scale randomization so it's different every frame and then i'm going to copy a box so you can see the box is now jumping every 10 frames and what i'm going to do is i'm going to use that to group points on the paper which i've scattered so i've scattered 100 000 points and now with the group we're gonna say you're now your temperature value has five next is this after that another point so it's going to be jumping from one place to the other igniting every time it touches that and then this is the same so i'm setting the temperature to five and this is the pyrosource and let's take a look at the settings so the cooling rate is much lower so we want the fire to stay longer the search rates radius is smaller because we have more points and the maximum number is 70. it it's fine like it's not going to have a big effect as long as it's above 50 and then i have some noise here and then also noise on the fuel but we're not using the fuel at the moment so we're simply using the temperature and this is the source all right so all of this was done on a scatter on different points it has nothing to do with the geometry well it is related to the geometry but this data that we have is not on the geometry so what i'm going to do is i'm going to use an attribute transfer and transfer temperature and burn to the geometry and burn basically one and zero has it be burned yet or no so it's a black and white value and then the temperature has more decay it has the it cools over time and it has a nice gradient that we can use to create these these types of masks all right so that is transferred to the geometry and then i cache it out to save disk to save sim time and the data is here the next effects that we're going to talk about is the heat distortion and this is where we see the paper getting distorted and deforming before the fire reaches that part so that's the thing we're going to try to implement now and this is very very simple idea and the way we're going to do it is let me try and draw something and i think it will help explain this so i only have a mice so sorry about the drawing but let's say this is the paper and we have a couple points here let's say we have one point here one point here and here and here and the burning source is like this so this is all burning and super hot so what we want to do is we want to affect the edges or pretty much everything that is not this and we want these points to move towards where there is fire so what we need to do is we need to tell this point where is the nearest location that is burning and once we find that that location we can compute the vector this vector will give us a direction so we have one point that is not burning second point it's burning this is not burning and let's say we uh we're able to figure out what point is that we can create a vector and use that vector to push this point closer to this point if we do this over time every time just one tenth one tenth of a unit we can slowly push the points towards the nearest burning place and uh because the fire is changing this direction and this vector is going to also change so let's say the next frame the fire propagation is only happening here all these points will be looking at this but if we have other resources as well available these points they'd have to figure out what is the closest point to them and use that to decide where to go and that's the idea but we're not going to do it just one time we're going to accumulate it over time so every frame we're going to take this force and apply just a little bit and that new mesh is now different because let's say we have four points right we transformed them using we pushed them towards this field and now those four points are maybe like this they're just smaller so this new position is what we need to use to do the new lookup so this result uh in in the solving basically and that's and that can be done using a stop solver so we're going to take a result and we're going to take data process that data and then the end result is going to go back into that loop and be used again in that system and that's what the salt solver is going to allow us to do so what i'm going to show is the how we can figure out the the closest points to create this vector from and what i have here is let me create a what i have here is the burning edge so i've created a mask and separated that and we'll go back to this burning edge in a second but let me just time shift this and freeze it freeze both of them and this is the all the points i'm going to create the point bop and this is my data this is the points i want to change and this is my source okay it's static right now and that's fine so let's dive inside we're going to use a node called xyz distance and this node allows us to do a lookup to find from an existing point where is the closest point from a second mesh like an attribute transfer or a point cloud lookup but this is simpler so we're going to use the second input and it's going to give us a primitive and a primitive uv so we're going to do a primitive uv lookup and it also returns a distance so let's take a look at the distance value you can see it's black and white mask so the closest points are going to be black because the distance is shorter and this point is too far from this so that's white and we can change this we can use a fit range and say my distance is 0 to 5 and i want to invert that range so only the places that are close i'm going to be white maybe let's lower this lower it even more so you can see now we have points they are aware of where the data is and this is the points that we're talking about here and i haven't imported data from the second input at all and that's not the plan here but basically we want this this mask so in order for this mask to work nicely i want it to reach all the way so let's say zero to five and you can see we have nice gradient now and the next thing is i'm going to use i'm going to import the point position from the second input so okay we have the distance we want to find where what point are we dealing with i'm going to use a primitive attribute node and it's called a premium v and the uv coordinate are the premium v the primitive number is this and the input is this and we want to import the p position and if i just connect this here we will get all the points to snap to that there's a opengl issue here but all the points you can see there snapped right away to the closest one and i'm gonna multiply this by that distance and let's connect it not so much happening so what we're gonna do is we have the point position so this is the point and we have those points here each point now knows the closest one and i'm going to create a subtract node and i'm going to subtract the point position from the nearest point on that mesh i'm going to connect this to n and let's visualize the normals you can see they're all pointing towards this direction you can see all of them they're taking us this way and if i add this information now if we created this vector if we add this information to the existing point we're going to simply shift everything so let's disconnect the n in the c and you see how everything moved so let's add a multiply by constant you can see how everything is moving but right now it's moving away so i'm going to invert the subtraction and you can see as i play with this we're moving the points more and more towards the distance okay so the next thing i want to do is instead of using uh just a uniform value or this result i'm going to normalize it to it so i only get the direction i don't need this vector to have a magnitude now the result is uniform so regardless of where the point is we're going to be moving everything at the same distance and i'm going to use this mask as a multiplier to change how this is working so i can make the points that are closer move faster and vice versa so see now we it's only see how it's pulling it's not the same anymore but we don't want to pull the closest more we want to pull the furthest more so i'm going to inverse this mask and now if i multiply you can see the furthest point are getting coming in closer and this is more the type of the effects i want to create you can see it here i don't care too much about distorting this because i really want to pull the far away things rather than the super close things again everything is going to move so that should be fine but i want to change the value so what we're doing right now is moving this pattern is very interesting i do like this pattern so let me put just a exploration thing because that's houdini see i want to delete yeah this is this pattern is very cool i think i think there's some potential to create some cool abstract art with this maybe some deformation oh it's only that i think we can do a polyline yeah there's definitely potential maybe you guys can try something i like the pattern anyway so i'm going to disable the time on this node and keep my geometry static so the only thing that's changing is this and let's see how that's gonna look on the geometry you see as i play through because that data is changing every time we're getting the snapping effect and that's not what we want so the way i wanted to do is once i deform the geometry this at this frame that's what i want to use in the next frame and then the frame after it's going to have the accumulation of all of that and that's where the sub solver is going to come in i'm going to create a solver node and i'm going to copy a node from the existing graph and i'll explain this in a second and let me connect this and let's copy this one and this is my second input this is my first input and again i'm going to keep the the geometry static and let's dive inside and let's go back actually i'm going to have both of them static to make sure that we have data to work with okay so this is my geometry this is my points where's the points i believe they should be here okay and let's go this is my geometry i'm gonna plug it here and so what this node switch node is doing is basically at the first frame we don't have a preview result so what we do is we simply use a copy of the first geometry input and then after the first first frame using this expression it's just going to switch so if i play through see it's going to use the previous frame because that's going to have data now so let's go back up and now we have this static maybe we'll use frame 20 so it's simpler and again the geometry now is not moving only this data is changing so let's see how this is going to play now and as you can see it's no longer snapping the geometry is no longer snapping but we're moving it too fast let's disable this and let's play let's play it now yeah it's it's too much the distortion is too much so instead of applying this much see a trunk right away instead of applying that much force we're just gonna go to this multiply node here and reduce this to something really low so every frame would just add a fraction of that so we don't move the points super super fast let's go back up reset the solver and hit play and now it's moving much better so let's uh disable the time offset and hit play i'm sure why it's moving oh i think i know why because there's a time offset so let's start this at frame seven and i'll explain this in the next video because i don't have frames until uh i don't have data until frame seven so if we hit play now you can see that all the entire paper is moving towards whatever source there is actually let's display that maybe yeah so that that's the points you can see once another source pops in it will take away those and start moving them towards this source and basically everything is uh just nicely distributed well not not so nicely but nice enough you can see we're getting this split so what i'm gonna do is i'm gonna smooth this result as much as i can and actually i wish i didn't have this much geometry because it's quite slow and i don't need that much accuracy for this effects so let's do a smooth and let's lower the quality set it to 20 and let's go back up and we can use other masks as well to help with this like if we wanted to change anything based on the uh based on the burn so maybe nothing that is being burned moves and only things that haven't burned yet so we use the inverse of the white mask maybe this is gonna leave the center areas or the areas that are burnt to be unaffected and only affect the areas the other places and look now with the with that smooth we're not getting that sharp uh split anymore the result is being nicely distributed and this is very very cool all right the last thing i added is because i wanted to randomize this a bit i added a noise to the to the geometry to the burning edge so instead of it being flat like this i just added this noise and that's just gonna make the uh break up the result a bit more so this is the final final geometry and i think i wish i did add more smooth because i'm getting yeah it's can be better so this is the final result and so one thing i i really can't explain this nicely without showing it without going through the example but having all these deformation being layered and being used with various solvers is quite tricky because what do you do first which one do you do first you do the crumbling of the paper first or do you do the uv distortion first or do you do i mean it's clear that we need the fire propagation but what i found is it's best to do the distortion first and then the crumbling uh of the paper so that's what we're going to do next we're going to blend this to have so that anything that hasn't burned yet is going to have this nice look and it's going to have the uv distortion happening anything that has burnt is going to have this crumbly uh black look with with lots of noise in it all right so we've created the uv distortion trick you can see the geometry is pulling and this is pretty much all i need for to illustrate this effect we are still going to add a few more things to this now i've cast the propagation the spread in this geometry and i also added a time offset so the time shift simply adds a seven frame gap so that the first frame is doesn't have anything and then only after frame seven we start seeing this now with this point bob i'm simply reading the data from seven frames earlier or after and i'm also taking the temperature remapping it and exporting it as a burn edge and that's what we're seeing here so the burn edge is gonna simply isolate this and it's basically this so temperature and i'm gonna isolate it it's fine yep so it's basically that that's the burn edge and i'm creating it as a separate attribute so it's it's not exactly there maybe here and i need more v-map yeah so that's the vern edge and then we have our uv distortion uv distorted mesh and again this can be any mesh it does not have to be the same exact one as the paper and uh what i've done is i use the point deform to apply that nice deformation to the geometry so this is the paper this is the deformed paper and i use a point deform and now that same deformation is somewhat happening to the mesh and i have more freedom now to even interpolate using this so i can i can increase the point radius again i have lots of points so it may not the result may not show here set it to 0.3 yeah it's it's changing a bit but again we have lots of points and they're identical so the result is it's very close and now we have our geometry with the texture we can visual visualize the texture here and i think with the smooth uv attribute 20 and one we can fix all these or at least make it much better the next thing we want to add is the real deformation to the paper being burned away so what i've done is i created two states a deformed state using a mountain node doesn't do much here a mountain node a point bob and another mountain node and then i separated the second area where the fire is so any anywhere where there is temperature higher than 0.2 this is going to be the form area 1 and this is the form area 0. and then i transfer that attribute to create a another mask so if i create a color here and i'm going to show what that means so i'm going to set this to red and this to black and i simply want to create a mask that i don't have so transfer transfer to from cd and this is black i'm going to lower the radius and we can get basically another mask that goes beyond the region and this can allow me to do more things so that's uh that's the idea between separating the two is to create this mask and i use the value 109 and then i'm going to use that mask to blend between the the sorted mesh to blend between the distorted mesh and the rest position and you know what let's create this from scratch so let's create a point bob and we need this color information so let's lower it to something like this and we have all the data here so this is the current position and i stored the rest position in this value what this means is basically i'm going to store a copy of the point position so let's dive inside let's create a bind node import the rest attribute which is a point position and i'm going to mix between the current position which is the deformed state the original position which is the undeformed state and use the the red channel so vector to float we use the red channel as the mix and then connect this here now we we have the inverse so let's connect the first one to be the rest the second one is the new position and let's set the color to white and now we have this so anywhere the fire has gone through we are getting this leftover state where the paper is super deformed and again we are still maintaining all that nice distortion because it's coming through the original mesh there's one more thing i added which is very very similar so i isolated the geometry again and i created the form area b i blurred the result what is this fade so this is just a copy of the temperature and i wanted to blur that just to get a nice spread and then i transferred again same trick from this to this and i used this new mask to add another noise explicitly on this area so see anywhere there's super hot fire it's gonna affect beyond and behind just around that edge just around the rim of the geometry we're getting this edge and now we're using that as another mask and this is going to add to the realism maybe it's not very visible here i think because of the texture but areas that are after the fire they're also being moved and then area behind it they are also being affected and then everything else the center when it fully uh crumbles and i think maybe we can go a bit higher with this one and that's it that's really it for the uh for the paper deformation and this is the final result and houdini crash so let me reopen it again and i'm gonna do a preview of the paper let's do it together and yeah you can see the distortion of the paper being pulled in and then the the deformation happening as the fire progresses now there's one more element that i don't have in the render i had it before but i i lost it for some reason because i was doing some tweaks let me see if i can find it so this is an early test yeah i had it here i think i'll do another render with this so you can see uh this edge here that is brighter than everything else i don't have it in this one and we definitely should have that so i want to bring it back in we see like a super bright yellow line progressing so let's see it's not here but we can easily add that so after the result i'm going to use a color node and just take the temperature or the burn edge attribute that we created and color it to be to have a yellow to red value and then we just add it back to the color and let's texture this with the with the actual texture and i think this adds quite a bit to the result and i will show how to render that as well so yeah this is an early test and with the we're gonna start looking at the fire this is also an early test with the fire maybe i can find another clip yeah i do have two more previews let me find them so this is another version of the paper okay so this is another early version of the paper you can see i have lots of uv distortion so just too much happening here and the fire is too at the scale of the fire is not realistic and actually in some cases you would want more details in some other cases you would want less details so that's what i ended up doing is tweaking it so i don't have as much details and let me see i have another test this is another version with that yellow edge included and just started building the the scene with the table and all so that's the that's the edge i want to bring back and this is our preview result and i think it's pretty cool so the next thing we're going to do is create the fire uh source and i'm going to do that by isolating the hottest area and we can check this by checking the temperature if it's less or equal than point one and higher than one we are going to isolate it so that's the expression uh to use here and then i'm going to use that geometry to scatter points on it and then map the temperature to go into temperature i really don't have to do this i think the default value is fine so we're just making it uh the points brighter and we could just say temperature equal one that's would still be the same and then uh a density attribute with some noise so just attribute noise and create an attribute called density it's not a vector it should be a float like that and then we rasterize this using volume rasterizer attribute and i only need density and temperature so that's it very very simple and because the fire is gonna most likely go up 99 of the time is going to go up i didn't add the collision geometry here because i know it's there'll be there won't be much smoke left to collide with the paper with okay next thing is the dop network and it's very simple so i have the source to input the fire source i have a power solver and i have a guess damp node to basically drag apply drag to the entire sim and it's only dragging by a value of 0.1 so like 10 percent every frame just to make it calmer so the settings doesn't really matter that much we don't need a lot of turbulence a lot of disturbance we don't need most of this we just need some dissipation and turbulence and here the turbulence is happening to the temperature not the density sorry the density not temperature because the default is temperature we always want to disturb that and that was not working because uh we don't want too much details i know this sounds weird but we don't need too much details this actually had a lot of details i think no this is the same version but this is an early version where i had a lot of details and i needed to find a way to reduce that so the way to do that is by adding a large scale noise to get just the flame to move you know and get stretched and then the trick is to diffuse the temperature diffusion so we want to blur the temperature every frame to get those stretchy elongated uh paper-like flames like these to represent small-scale fire and i think that's really it there's not much else happening i then catch the fire so this is the source and like i was saying what i don't like the most in my render or at least the first thing i want to fix is that amount of smoke i think it's too much and i think the fire spread goes up too high so what i can do is to tweak that go back in the solver reduce the flame point one and also turn off i don't need any emit smoke i don't need any emit temperature it's going to be just fine if we need more temperature we can increase it here to two but that should lower the flame height and reduce the amount of smoke and the reason i want to do the smoke in sim is because they are interconnected so if we have density it's going to affect the the temperature and they they both work together so it's not like hiding uh the smoke let's do uh let's copy this all right let's create a pyruvate node and i'm going to go to the fire turn it on and this is displaying our temperature field i'm going to set it to 50 and i'm going to lower the smoke density 2.1 you can see we already have a lot of fire and that's the stuff i was talking about like if we hide the smoke it's not going to just fix the problem that we're having we can also create a mask based on height so let's set this to two maybe five yeah something like that eight and just because i like you guys i'm gonna create this mask based on height for the temperature so i'm gonna create a volume vap let's create a byte node okay the temp bind the temperature and then bite export the temperature again i'm going to use a vector to float get the y position use a fit range to remap it use a ramp node because we want more control obviously and i hate this but the float ramp almost comes empty i don't like that so let's export this and let's make sure we multiply our result with the temperature and let's export the min and max and let's find the balance so i think let's go down what is the range so the max is 4 and the min is 0.1 so minimum let's inverse it hm let me see maybe i picked a different yes the y position let's just connect this here and tweak it so that we get the nice gradient from here okay so like that but we need to inverse it so i'm gonna use set this to one and this to zero and let's connect this here and now it should work yep and you can see the smoke is still there so i'm gonna just hide it completely you can do the same thing to dissipate it okay and let's play with the ramp and let's do this instead of using the current point position see now the flames maybe let's just flatten them so we have more data to look at so what i can do is i can create a noise let's go with a turbulent noise and add this noise as a as a vector to the current point position and that's gonna that's just gonna offset the uh uh the y axis so let's set this to 10 and this 2.2 0.2 0.2 this is to 2 let's increase the frequency yeah you can see it there so now we're getting more uh breakups and this is great yeah i don't think we need that much fire but again this would have the smoke be different so maybe it's just a matter of rendering this um maybe it's just a matter of rendering this as the temperature and let's let's go even more crazy let's do this let's create our own density field pardon me so i'm going to isolate the temperature right so that's my temperature field i'm gonna name it to from i'm gonna rename it from temperature to density let's see so name temperature now density okay i'm gonna remove the original density i don't need it here because we're going to replace it with our own so maybe the temperature is only is the maybe the density is the original temperature field that it is elongated and then the new actual temp is the new masked one that's the idea so let's delete the density here now we have the we have a remap temperature and i'm gonna merge this here and now if we look we should see that's our old temperature by used as uh as density now i like this i think this can work okay so the other uh cool features from the bake is the uh the scatter which is quite cool you can see we're getting this nice glow in here and it's going to create a scatter fields so we can build this or connect it into the temperature just use that and let's just do a preview i think we are good too much fire flat shaded so we don't see the bounding box and let's do uh let's increase the resolution to 1024 and let's tweak the settings so that we can see the full volume let me find this data because they keep changing it texture limit texture hdr texture is full hdr texture is full hdr and then there's another one i believe under scene yeah to enable this okay let's go back and forth and now we're displaying the volume at its full resolution let's uh do a capture now and i'll resume in a second let's see how this is going to look like so the preview is done and i'm pretty happy with the result i definitely like the amount of smoke better and the color as well and the fire feels more natural now this one that i did i'm not super happy with the with this smoke but the fire is is good so i think combination of both would definitely be ideal so this is the original version that i showed in the beginning and what we have been working on and together we've made couple of adjustments that i really liked and decided to re-render the two shots that we have and so the main tweaks or the main thing that was bothering me is the amount of smoke and how long the fire is we've made the post process together to basically limit the fire and used the original temperature as the density and i also was missing the edge of the flame so the edge of spreading in the shader and i've decided to bring that back so what i've done is one more thing i also saved out a new cache of the paper with a smooth value of 20 and quality of two this one has i think lots of stretching the new one one has less stretching so i've took the the file everything we did together so the this is using the live file that we made and here inside the sub solver the quality is higher in the smooth so 10 and two and then i also did the tweak to the fire so this is what we did together using the height and then i wrote out a new cache for the uh for the smoke as well as the geometry so for the geometry this is the old one and this is the new one so let me move it to the side so this is the new one you can see the fire now does not go that high and there's not so much smoke and again the density field here is a copy of the original temperature so that in the previous was mainly temperature and now with with the new one i think it works much better with the edge as well everything looks much cleaner and the uh there's not so much distortion on the uvs because the smooth quality is much better so yeah i re-rendered the shot and this is another camera angle from the top panning i have lots of depth of field going on alright let's see so i think that's really it for uh for the tweaks and i showed you how uh the new renders look and we're gonna talk about uh rendering in the next few videos so what i wanna show in this one is actually trying to create taking a risky move here trying to recreate something like this and the geometry for the for the paper so we have basically details and noise around the the edges a little bit of noise around in the center and then we have this nice bump across the board that actually shows up quite well and i do like it i don't know about you guys but this wrinkly feels it it makes the paper feel that it's thick and it has been wet before and then it dried so you get this wrinkly texture at the top so that's coming from the geometry and the top solver so let's try let's see i'm going to create a grid and i want to make it the same size of the of this paper so let's just approximate that and again i'm gonna do it live show some ideas and maybe you guys can explore this more and let's create a texture node and set it to point mode and what i'm trying to do is basically isolate or create a mask that fades away from various angles we can do it in many ways we can create a a line around this and transfer the color and get a nice mask or we can use the uv and that's what i'm gonna do so let's connect this here and let's increase this to 256 256 let's move the plane and round these numbers and let's dive inside so we need the uvs vector to float i'm going to take the x and plug it through a ramp and let's take a look at that i'm going to hide the colors so this should look white oh sorry new v okay so let's isolate the top and bottom and that's going to be white and same thing here and make this color white and let's do the same thing for let's call this ramp u sorry ramp u and it resets itself terrible and ramp v and let's use red and green to visualize this so float to vector and i'm gonna take the red in the green and let's do this again and there's a trick here if you show the color oh something is happening with houdini and open colorado so let me restart and we'll resume in a second okay so we're back and i think it's gonna crash again i've noticed this when i move the viewport edge or rescale it uh houdini crashes i think maybe fixed in the new one i'm using the 383 which was released three weeks ago there is a new one so the trick is you can visualize a red green and blue in the viewport so if you have colors you can isolate that without having to do anything okay let's create the mask again that's the red and let's take a look at the green white okay and let's dive inside and use this as a mask to create a noise so i'm going to create a turbulent noise and just add it to the point position and see how that's going to look first and then we decide what to do with it and i don't need the colors and this needs to be a 3d i'm going to change it to zero centered noise i'm going to increase the frequency to 4 4 and 4 and lower the amplitude so that's one and actually i want to separate the two so i want the left side separate from the red side sorry the left side separate from the right and top separate from the bottom so this one i'm going to let's set this color to red and this to green or let's set it to blue okay and now i can use vector to float and vector to float and i can multiply this result with that mask okay and then let's add this to the point position actually let's multiply the noise and let's add that to this cool so we're just distorting this area okay so i think the height the push and pull is too much which is happening on the x and y and what i'm going to do is i'm going to separate the vector to float here and then float to vector and let's move this here i'm going to create a multiply by constant for each one so y x and z and now we will have control over how much influence so i don't like the uh the side to side which is the z i'm going to set this to 0.2 and see how it's moving back because i don't want to distort that and then the up and down maybe you can go a bit more not too much let's just leave it at 1 and here 2.5 cool so that's one one thing one effects i'm going to copy the same thing and instead of multiplying it by the red i'm going to multiply it by the blue so this second noise by the blue and let's add it and i'm going to change the noise to be strike simplex and now we should see it here by the way oh let's see okay that's the first one so we were looking like this and this is the second one pardon me two i'm going to make the noise bigger here and i want to make it uh go further so let's drag this blue in okay and the same idea is going to apply for the sides as well so let's copy this vector to float and let's see what colors we have we're gonna use the the red same thing sorry red and blue and i'm gonna copy this okay and one is gonna be the red and the other one is going to be the blue this goes here and all this is going to get added together and you will see how the sides are going to be deformed now so this one side and this one side again i'm sure there's other ways to do this effects but i just wanted to show what houdini can do so let's pick a different noise here and let's lower the frequency on something big see that line there i want to fix it so instead of linear i'm going to change it to let's see let's try busier yeah maybe we'll just smooth it out later it's a bit tricky with just colors okay i do like the noise though so let's keep let's use the same one here and let's lower the frequency as well and the amplitude and i want to make it tighter on this side okay let's add another noise to everything and let's use let's see i want to make the noise only appear in the center so let's copy this let's call it center and let's copy this and call it center and i'm gonna add both of them and i will show how that's gonna look like as colors okay and what i'm gonna do is move this here move this here and same thing and we'll smooth it out and add some noise and let's use that as a multiplier for a another noise let's pick let's pick a turbulent noise okay it's fine connect this to position multiply it by this new mask and let's add it and needs to be a 3d noise and frequency is going to be much lower and amplitude as well that's very cool okay and let's add one more using the mountain node and reduce the roughness to get something like this and the amplitude as well okay and then we can use the bend node to add some interesting deformation i'm just going to copy this from the previous example see there this one and this one we can also do specific uh beds so let's copy using a soft deformer let's say we want to twist one corner let's do it here so everything stays the same i'm going to select all the points or some of them from this side probably better to use a grid sorry a group node and do this but let's do it this way i'm going to use a soft deformer and move this up and rotate it and it is too much so this is what i do i'm going to put down a blend shape node connect this here the original one and the second input and now i can tweak that amount and let's add the noise back in so yeah i think it's it's not exactly the same but i think we have some cool uh details and let's add that last bump as well using a mount node mountain node and let's increa lower the element size and let's lower the amplitude and lower the roughness yes something like that all right i think we have a very cool paper now let's take a look at this with the with the current texture okay and let's get because the uv is different and the texture was based off of that let's just scale it i can't do it here okay let's do a uv texture again it's not going to be accurate but we can use the scale never mind just nope no idea what's happening i'm not sure why it's doing that texture let's try uv project okay let's see this one allows us to do yep this works better and let's slide it all right i think this looks pretty cool thank you guys for watching sorry it took longer than expected i'm doing it live so sorry about that i hope you learned something new so one more effects that we could explore is dissolving the paper into ashes right after it burns so there's nothing left and i'm gonna show how to implement that and we can easily do that by using a color node and remapping the temperature to get the various masks that we need so let's use a color node and put down write down temperature and this is the data that we're going to be deleting so this is the paper and as the fire goes through it's going to delete everything behind it but we want to isolate an edge that we can use to emit particles to give the illusion that this material is dissipating into ashes and we create a particle sim off of that so this is to be deleted the other thing we need is the actual source emission which we can extract like this so we can isolate a section and this is going to be the source maybe it's too far yep let's delete everything else okay delete points and here we're going to delete the same thing but not selected right so if i uh let's let's put down a color node and just restore the color so as i play through the fire is going to start coming and it's going to delete what's left behind it so we see fire but we need to see the effects of the particles being emitted and that's what we're going to use this source for so i'm going to scatter points on this i'm going to use a pop network and let's go inside and use all points and give them a short life so one second one fps sorry one t is 24 frames per second which is here so that's one and i'm gonna randomize them and let's give them some noise uh at the beginning so we're gonna move them up and variance is 0.5.5 and also some noise to the sides and let's hit play and we should see the particles going up and it's going to give the illusion that the actual particles are the ash are blown up so i think five is too much let's try point one and variance point one on all of them and let's use a pop force and add some swirls let's add two yeah one big and one small and let's see how that's gonna look yeah something like that i think the noise is too much but we get the idea size 0.5 and one and three and let's go back and try to do a play blast to show how this is going to look like maybe give this a red color orange color and this is the paper and let's visualize the fire as well which is here let me check yeah the fire is here so let me visualize all of this and i'm going to do a play blast and we take a look in the next video at this i think the particles are too much so i'm just gonna lower it to 500 and let me do a play blast again this is just an illustration how you could do the dissolving effects if you want to explore that here's a quick preview of the dissolving effects that we did there's definitely a lot of work that needs to be done but if this is something that you want to pursue this is how you would get started on it the main thing i would change is the delay i would delay the particle dissolving maybe one frame and just move it behind the fire a bit because right now it's overlapping with that we would need more points and we would need to make them ramp up from uh orange to black and fade them away very quickly so that we don't have any anything left all right guys good luck and we're gonna start talking about the rendering side of things now so let's start building the scene and prepping the rendering side of things and what i have here is a website called polyhaven and if you want to support this it's a great initiative what they have here so basically they are they are running in patreon and use that money to create more content so the more money they get the more contents we get and everything is is free and you can build a very cool scene you've got tables you've got this brass vase and there's a latter that i used a clock a chair i believe i picked this one nope i picked a different one a gothic chair this is the latter so let's let's use this one let's download it and here inside the edit i'm gonna change it to zip and what i need is the gltf format and we need we can just use jpeg for all of them and click download and i have the file already extracted in a folder so i'm gonna go here and there's no as far as i know there is no current way to do this in subs so you have to use the main menu and if we go under the import you will see this format called glyph gltf i don't know how you say it but that's the format and then i'm going to browse to this later and import it it's very very cool so you load in the geometry and it comes with the the elements so two geometry nodes and a material and this is what we need to copy into karma so the way i've been doing it you can save this out as usd and copy this but there's a simpler way that we're going to use i'm going to go to stage and now we're inside karma or the stage context and i'm going to create a sub create node call this the lateran metal and i'm going to copy it again and i'm going to call this glass and let's create a material library node and let's go back and copy stuff from here so i'm going to copy what's inside this so this is the i believe the glass let's go inside yep and just i just dove inside that swap create and pasted it this is gonna have the data inside stage for simple assets it works perfectly you don't need to do anything fancier so i'm going to copy the mesh as well and go to stage and paste it here and let's merge all of this into a scene and let's create a grid and add it to our scene cool and let's connect the material library and we should have to as well so everything comes pre-built in so i need these two and let's go to stage again dive inside and paste them and now we need to assign them so assign material i'm going to switch to my solaris ui to show me the explorer and under the assign material i'm going to grab the lateran glass that's the primitive and the material is going to be this and let's do the same thing for the metal and that's the geometry and this is the shader and the drag and drop is not the best when i'm recording so let's see i can make this smaller okay and the texture is loading already and we are rendering inside of karma now so let's create a skylight an environment light and let's create a merge node and group all of them in case we wanted to add more and let's put another merge here to connect the scene with the lights and this is where the merge is going to go and then we have the later imported into stage and working nicely so we have a few more things that we need to set to get the light to propagate through this other than the material and for now i'm just going to create a light and i'm going to make it a sphere and make it smaller 0.05 even smaller 0.005 and you can see we don't see the light itself so we can change that if we go under karma create our set and render geometry light and now we can see it but once i move it inside the object we don't see that anymore so we're going to fix it in the next video to see how to set the object to be invisible and let the light come through and let's reduce the intensity of this light and change its color to have a bluish tint in the center or the lateran light to have orange color and let's crease it to a hundred so the latin is working nicely now and the the only thing left to do is to make the glass invisible or transparent so first thing comes to mind is to go to the shader make sure it's transparent which is not the case here so let's increase the transparency to one and it's quite glossy right now blurry and the reason for that is the roughness is too high so let's set it to 0.1 let's set it to zero and it's still not coming through and the reason for that there's a bump which is not working quite well for the glass so i'm just gonna turn it off and boom we got our object we can increase the roughness of the light and make it glossy as well and this is going to change the depth yeah it's not going to do anything here i wanted to make it rougher let's reduce the metallicness maybe the reflection yeah okay we can go above uh one so yeah i wanted to create something like that it's gonna be noisy but i think it's gonna look cool uh let's put this back to one in this to one and the the the main thing we need is the light but it's not coming through right now what we're seeing here is the reflection and the global elimination of this object being bright and being reflected what we need to see is the actual shadows coming from the latter and that's not happening even if i increase this to a thousand it's not working so we need to do one more thing we need to use a a geometry setting and we need to make this object invisible to shadow base so under karma i'm gonna go render visibility and there is no option for this here so we have to do it by hand i'm going to type in minus shadow and once i do that the light is coming out now so this object is visible to all rays except the shadow rays so let's increase the light intensity and there we go we have a very cool lattern with a nice glow at the center i do believe that we can still make some other adjustments under opacity and use enable fake caustic to also get the object to be transparent but removing it from the shadow visibility is just more efficient in this case okay so let's bring in our paper i'm going to use a subcreate node we've cached out the data to disk i'm going to use a file node and just import that in so this is what we have and i've cast the color information with the edge as a cd attribute okay so all of this is included in the shader and we just have to read that which is which happened by default so we just have to make sure that that gets plugged in correctly so let's connect this here and i want to move keep the lateran with the light separate so the grid let's move it here and let's create a merge node so in case we wanted to move the ladder and we can just include the light with it and for this we're going to call it paper and let's see where it is oh it's too big okay so let's make it smaller yeah it's not realistic but i'm just going to show how everything works so and later i will show the final scene with the final layout and everything needed all right so we have the paper we just need to assign the texture to it let me move it down a bit okay and let's create a principal shader i'm going to use a mantra sorry the all shaders you can use material x i haven't explored that yet but you can explore that so let's call this paper and i'm just going to set it to red make sure it's working okay let's go up and under assign i'm gonna drag the paper and this should be called paper cool so let's import the uh load in the texture file let me copy it from the original scene and that should be here let's go inside and i'm going to set this back to gray and under the base color just gonna paste the texture and let's set this to one one and one and now we have our texture loading in and it's being multiplied with the with a color which is very cool and i think that's it that's all i did for the for the paper the only other thing that i faked is i wanted to give it the illusion that this paper is translucent so if you look here under the shadow it's not super dark so this shadow intensity is not too high which makes it feel as if the light is coming through the paper and what i did is under opacity i'm going to turn on opacity and right now you can see the shadow is gone this is great for creating bubbles and things like that i'm just gonna increase the opacity shadow past here you see it's much lower now all right let's take a look at the final scene and i will go through the fire shader there and the layout and pretty much everything i did to keep things simple i've decided to use and create the fire shader again from scratch so i'm gonna use a volume node and i have the path to the vdb files i'm just gonna connect that in and let's use the same transforms that we applied on the on the paper on the volume to line them up again so scale is 0.05 and the transform is this and now we should see the fire yeah i think i think it is there but it does not have a shader so let's connect that and what i'm going to do is i'm going to use a starting point and use the billowy smoke shader and call this fire paper and let's go to the aside material and let's call the volume fire vdb fire vdb this is materials and fire paper okay there you go that's our fire right away and let's go inside and because i mean there's not so much here to tweak we would just need a nice ramp for the fire so let's reduce the density to zero i don't need that right now and let's go to the temperature and change this preset to just have orange and let's change this red to be more interesting all right let's increase the intensity to 100 and that's the initial starting point i'll show how i made few more tweaks to this inside the shader so let's talk about the scene layout briefly i have the paper and that's the main focus here but i've decided to nicely present it so i put a table put this statue here to reflect the illumination of the paper and then we have table we need chairs so i put two chairs to get more parallax i also have a cabinet and the latter is on top of that but we don't see it unfortunately and i didn't want a super bright source next to the paper because that the fire is going to be the main illumination source but i kept it anyway so let me show you the the scene it's fairly straightforward and then i will show the fire shader tweaks that i did and that's it in the lighting and then we're gonna talk about some compositing so this is what we have so far and this is the important uh elements that we need to know about and then everything else is very straightforward so i went ahead on the polyhaven website and got the chairs and the table i believe is from there maybe from mega scan it's the same it's easier to use bully haven because it's free and then the latin here and the cabin cabinet but it's longer so i just used half so the latter is not too high and these things are imported the same way they came in as a glyph gltf format again sorry i don't know how to say that i don't know how to pronounce it properly so the wood chair the bust this is the the head i subdivided it to give it more geometry then use the facet node make sure we got nice normals this is the cabinet and this is the wood chair and again they just came in with the textures i plugged them in i didn't do much there and then for the statue same and all the shaders are here so there's some new stuff that i'm gonna delete so this is all uh what came in with the with the scene and the only thing that we have to be careful with is the bump because if we change the size we have to make sure the bump is working correctly in some instances i had to change it to object space that's the wood chair this is unused this is a vase that we don't have and this is the paper so very straightforward not so much there and the texture it's exactly what we did and this is a displacement or a bump from the uh from mega scan but we don't have we don't have to use that all the details are in the geometry and this is the shader for the for the fire so this is my ramp this is the smoke color and this is the density value and i didn't scale the paper or the volume i scaled the environment so the density will affect that but a value of 3 and 0.5 and the temperature now one more thing i did is inside here there's a temperature remap where is it there's a temperature min and max to just fit the temperature field better and i use the value of zero and two so this is the min max and then i plug that into a ramp which does not make much of change it's just linear i didn't use it and then the second ramp i believe is not currently used uh the second rep is to multiply based on the density but it's not doing much because the density is is new anyway so i was taking the density remapping it and use that as a multiplier make sure that i only have temperature in the where there is a density but i don't think it's needed in this case so that's pretty much it i started off with the billowy smoke still called that and that's what i used for this example all right now for the uh for the render settings very simple i set this to 48 i used a touch higher resolution just to get bigger images and then i um i wrote out multiple aovs this is needed for depth of field if we wanted to do that in post and then for the denoise and i also included the direct indirect diffuse so i can get the fire elimination i can be able to control the fire elimination in comp and yeah the direct and indirect emission the direct and indirect volume and i included sss but i didn't use it i just left it there and that's it for the settings everything is well explained in the previous videos for the museum and the karma arrows scene and this is all the shader assignments so i'll be including everything uh here except the assets i cannot we cannot share them so i'll post a link for the poly haven geometry where i got it from for the chair the busts and the the cabinet and the table you can replace from something i'll provide something as well so all you have to do is plug in the geometry because again we can share it but we will include uh all of this in the scene and the the mega scan displacement it's also we can't include that so include the procedural one but if you have mega scan account you can just plug it and create the same the same one so for lighting i kept it very very simple and let me switch to karma and i'm gonna disable three and just leave one light and let me resume the render or restart the render so for the illumination we have the latter which is at the top left here and honestly the main illumination is going to come from the fire so that's what i was looking for but i have the latin so that's what the illumination looks like let me go back a little bit so we can see it and i'm going to enable the next light it's also a spotlight with a bluish tint at the top to get the nice specular here on the on the table and they are very they're not too strong just lightly visible and another point light here to get some more elimination into the center and then i have a an environment light to eliminate everything using a texture and the texture is from the same website i believe hdr haven and it's called photo studio loft haul underscore 4k so it's just something that had that is interior it has red lots of red tint and that's it i set uh i set the environment tag the light tags to environment in i believe one two three so that i can control them in comp so this is our render uh loaded in nuke and i've run it through the denoise in houdini and this is the final result that we have i'm pretty happy with it i'm just going to show you guys how to combine it again if you want to make any adjustments so what i what i've done is i've separated auvs and because we included them we can separate them so i'm going to put down a shuffle node and i'm going to select let's say the environment light so this is how it would look like and then we have the lateran light so we can composite and separate each one of them and let me take a look let me show you what we have here so this is uh light two i'm just going to call it two i've separated each one of them as well as the fire so this is one and this is the latter and this is environment and this is three i should probably have named them using better name and this is the fire we can find this under the emission direct emission and then we have the indirect diffuse we don't need this it's already included in the render in the other passes and this is the indirect emission so this is the elimination from the volume from the fire itself indirect emission and this is the indirect illumination of the fire onto the volume so indirect volume and then we combine all this we should have very close or identical render yes identical awesome so now what we can do is if we didn't like any of the lights sorry any of the lights we can just turn them on and off and this is only the fire illumination by itself right i want to make this uh more intense so let me put down another merge node and i want all this separate actually these two separate plus and i want to combine them with the with the original image and then i want to add the fire at the end so plus and let's move the fire here and let's just take a look at this without the the other lights or have them here but reduce their intensity so let's do one more tweak so that we can do a speak the entire lights and only focus on the elimination of the fire so the first thing i want to change or increase is the elimination i want that to be much more visible i'm going to desaturate it change the hue a bit so hue shift and just a touch and desaturated a bit because i think it's getting too red maybe not desaturated yeah something like that the fire is very sensitive like if we go one one rotation we we lose the the correct values and what do we have here this is the illumination of the volume so let's see how that's going to make it look i think this will give it that glowy look inside and this just going to make it feel much thicker i i don't want that just a touch and then this is our first fire so i want to make this more interesting and this is what i'm going to do i'm going to desaturate it completely and increase the contrast and lower the gain and basically separate the brightest area and i'm going to multiply them with a different color like that just to get this bright spot and i'm gonna merge it back in so this is the original and this is after the tweak see we're getting these nice spots i'm also going to do one more tweak let's do it the same so instead of going yeah instead of going all the way down i just want to get another tone and i'm going to make it warmer like that and let's combine this so this is the original and this is after tweak and i'm gonna increase the gamma here and reduce the intensity just to give it more contrast so basically we made the bright brighter the mid wider and the the the low intensity uh stuff we killed it or reduced that so we have more contrast in the overall and we get in the overall image we get these nice highlights i'm just going to add that here and let's hit play yeah the fire feels much more intense now and i think with the everything darker it feels it looks cooler honestly with just the elimination of this all right so now i can bring back the entire environment yeah i think it's too bright so i definitely want to balance it and let's see which one is causing this one the environment is too strong i'm gonna reduce that the latin is also too strong and this one this one i'm gonna tint it more with blue and create more contrast in the image and let's see yeah this one is too red so hue shift i'm going to desaturate this one all right pardon me i'm going to create a vignette and this is just going to add a gradient and it's a it's a gizmo you can find from newpedia see i'm adding darker edges and i think the fire is too yellow so i'm just gonna use a hue shift node and just move this a touch and i think that's pretty much it for the comp the final result has some more lifting like i'm lifting the blacks a bit more just to make it feel more cinematic but overall this is the important bits on how to tweak this if you want to make any adjustment in comps all right so let's recap everything we talked about and what we covered today and this is the final result that we created together and this is the result that i composited myself i have some lens flare and i just lifted the black a touch so it feels it has this a warm red tint but overall it's very uh very close now we talked about using textures to create the paper we talked about creating it procedurally we used the soft solver to create this interesting warp and distortion effect we talked about using the spread source to mask the ashed version and the noise dub paper versus the original and there's also cool cool details here that are happening just by chance see this warping this pushing here feels like the paper is melting and creating this edge honestly it's luck and also the end see this white edge it feels very natural like the fire didn't finish that so all this i i didn't plan for it specifically to happen but i think it happened houdini it's very cool and we talked about using the spread to emit fire the fire simulation was very very simple and the underneath smoke i don't think it's visible here yeah it is visible you can see it there but it's not very visible i don't think anybody noticed that there's also some here so basically what i did is instead of emitting up i emitted down and i used the flat plane to collide with it and instead of using you know temperature going up it just used temperature going down but yeah i wouldn't worry too much about that so how can you take this further well the uh the next thing would the uh cool that we can add is to have the shader actually change the specular roughness or even remove that completely based on the temperature so we have a nice mask called temperature and we can use that to drive values in the shader so if it's a white then we don't need roughness if it's black then we need roughness or we need specular so that's something we can add and maybe we'll explore that in the next uh tutorial to read custom attributes and drive shader and the other thing we can add is to have this paper actually dissolve but not entirely dissolved just fall in ashes and that's going to be much more complicated but maybe something that you guys can explore and i think that's pretty much it hope you learned something and we'll see you soon in the next video bye you

Channel: Rebelway

Views: 15,455

Keywords: Houdini Tutorial, Houdini, SideFX Houdini, Nuke, Nuke Tutorial, VFX, FX, VFX Industry, Special Effects, Visual Effects, Hollywood, Simulation, VFX Tutorial, VFX Tutorials, Burning Paper, Fire FX, Fire Houdini, Fire Houdini Tutorial, Pyro Houdini, Paper Burning Tutorial, Advanced Houdini Tutorial, Houdini Burning Tutorial, Saber Jlassi, Rebelway Tutorial, Best Houdini Tutorial, Fire Tutorial, Houdini Fire, Houdini Flames, Houdini Paper Burn, Houdini Smoke, Smoke in Houdini

Id: I5yo9LiItZc

Length: 122min 21sec (7341 seconds)

Published: Tue Nov 23 2021