Meteor in Houdini and Karma | Pro Houdini Tutorial

so hello hello everybody and welcome to another awesome tutorial my name is urban verdesco and today we're going to be taking a look at how to create this amazing well i think it's pretty cool meet your effects we're going to be using podini 19 and we're going to be rendering this out with karma we're going to be attaching a hip file the one that i'm using right here grab it and follow along i hope you learned something valuable and let's get started so we have a few different elements here that we're going to be taking a look at how to create we have the meteor itself which is just you know a simple rock that is that we animated and then we have some secondary elements that are well first off we have the primary element which is the main smoke that is being emitted from the main meteor plus a few medium secondary smoke trails and then we have some tiny ones the tiny smoke trails that really help sell the scale of the effect and you need some tiny ones and then we have some super tiny ones that are literally just super tiny trails of just smoke being emitted from you know really the smallest particles and all together it looks like this i think it looks pretty cool and also we can uh let's see clouds we're gonna when you put in some clouds now it looks very cool right and with the new uh shading on the volumes with the ambient occlusion i think this looks pretty cool even without rendering anything if we quickly take a look at how the render looks like it's here on the right pass render oh i guess there was a preview from the render from before yeah so that's kind of how it looks like i think it's pretty cool and yeah karma is the karma is pretty fast for these types of situations but yeah that's how it looks like uh when you render it with all the clouds and everything and you can see mount mantra karma is doing a pretty good job at rendering everything at a decent speed uh given that we have pretty much just volumes in the scene and they're overlapping each other quite a lot all right so let's get away from karma for a second i will make more space here so this viewport is a bit bigger and let's go into the shot creation so these are the elements i'm going to be showing you guys a special kind of bonus element that i was not using in the end but they're like very cool sparks well i think they look pretty cool and you can use them for multiple different things but if we go from the beginning well here are the three elements these are the super tiny smoke trails the medium smoke trails and the big smoke trail like so and if we go from the beginning we start with a very simple sphere sphere has a lot of polygons because we're gonna be using a mountain on it and also i'm uving it even though i in the end i was not using materials but uh i did uv it just in case if i was uh about to use a texture on it and this is all static here mind you because we're going to be animating it soon and then i'm going to be kind of showing you guys how i would deal this in a studio or production environment where let's say you get the animation already done you know by the animators and they would just give you a cache and if you just have a cache you would have to do a few workarounds that i'm going to show you soon but so we create our mountain which is literally just a simple mountain with a worldly uh silly cellular noise it's hard to pronounce and we have here an attribute warp that you can use if you want to it just gives you a very cool lava meteor shading i didn't end up using it for the render because you don't see the meteor at all it's completely covered in smoke that's why i turned it off but you can use it if you want to okay next up we do a vdb from polygons and a scatter inside mind you here you have to switch to density we do an attribute randomize all the normals because we're going to be copying a few grids for that you just put down a grid you uv it again not necessary i just thought i'm going to be adding a different texture on the inside of the so if i quickly show you when we do an exploded view i was thinking about doing a different material on the inside and i didn't end up using it but i uv this just in case so we copy to points without using a random normal orientation everything is just going to be copied like this and then the normals are going to be dictating the orientations if you go here inside sphere and you do this you're going to get a very random orientation put down a mountain to get your cutters boolean fracture and that's it it you have a fractured thing and i think it looks pretty cool at least it works for our case next up well i guess i have an exploded view here i'm going to create a rest and i'm creating this before everything starts moving and i'll show you why in a second and here all of these nodes are for animation now i'm not going to be showing you guys how i animated this but so this one was just to kind of rotate it so this was the front of the meteor and this is the back now i did a transfer on the rotation just dollar sign f and you multiplied by two and this is going to be now using the timeline to animate this main move literally just i think two keyframes i don't know why i have more keyframes they should be just two so it's in the y and in the c these are the two most important ones anyway and it's gonna go look at it look at it go like that we look at it through the camera there we go looks like that and we're kind of following it following the meteor going down so that was the main move just diagonally animating it down and scaling it up because it was very tiny when i started modeling this you can see it's not even a meter and that can make a huge difference when you're creating volumes oh i just thought this is still playing but yeah using a bigger scale it's gonna come into play when you are when you are doing simulations because uh you i usually try to do everything to scale without faking the scales too much and that's going to help you in the long run so if you want a big big meteor falling down just make it just make it big even though this one is still quite small all right i in this case i was assembling everything so that would just give me a few points but if you mean 2 000 on just like separate pieces and then i did a point velocity which gives me a velocity vector of everything falling down right so now we know we have a velocity we know how fast things are going in and what direction they are going with this guy i was creating a random group based on the point number so if i read it for you guys make it bigger so if random point number plus a seed value which is would give which is going to give me uh a seed so if i quickly show you guys how what this is even doing i'm gonna blast it so this is going to create a group called shards and if we remove that group we're going to see we get charts and i'm just creating a random group based on the point number if that point number is below a certain threshold you are in the group called shards so if i start changing the uh the seed you will see it's going to be changing the shards here for me it's a bit annoying this visualizer but you can see it's going to be changing the seed i'm going to go back to the seat that i had this one i am creating a centroid and you can see i'm plugging this into the second input here and that is because if and also keep in mind i'm using detail to run over detail which will just run over this code once what i'm doing here is i'm creating an attribute called center and then i'm using get b box center on the zero first so it goes zero one two three on the first uh well actually on the second uh input and on that this will create a position and using that position we create a point in space now if we did the same thing here it's going to still create that point but it will also and just put this to a 0 now so now it's still going to create a point you can see we have 2099 points and in this case we have two thousand and a hundred it still creates the points but it's still running through all of the other points and that's not what we want we just want to just create one point and based on the centroid so that's why you would plug this in the second output and it's gonna just output the point that was created and now i'm going to negate the position of this point so we got our point and this point is still moving based on you know our meteor it's right here you can see it's in the middle and with this wrangle we negate it we i pick the point attribute the position attribute on the points from the single point that we created and i say what is your position do that but the opposite and that's going to negate it and put it back into our centroid well sorry back into the center in the world position so why would we do something like that it's because we imagine if you don't do this transform imagine creating all of your effects on something that is constantly moving through space and then you emit points and you have to check it if if the collisions are working then you will close and then scrub forward and then have to you know it's just a pain doing it like that and it has some other economic uh reasons why you would do this but one of the bigger ones is you just get more control and more speed and you know obviously i could have done this all of this before i did the animation here because i was animating inside of houdini directly but usually you don't get the luxury of having these uh this information here you just get a cache that already has the animation baked in so you would have to do something like this now this is the simplest way of doing it you can also try inverting the matrix the transformation matrix and the rotational matrix we're not going to cover that in this tutorial but this is a simpler version that works in most cases it's not going to negate the rotation in this case and we actually do want rotation because if we also negated the rotation and then we use this as a collider it the you'll see our points are not going to be colliding in the right way so we kind of do want rotation we just want to negate the transformation so that's what we're doing with these nodes here all right so now we have this back in the center and it's shattered and it's rotating so i'm gonna split between i'm gonna split the shards between uh the shards and our main meter on the shards separately i add some additional position transformations and noise to the position and that will essentially give us this movement that let me quickly preview this this will essentially give us the movement of a meteor falling down if you if you imagine like everything is falling now and some of the pieces are kind of being left behind some of them are staying a bit and lingering a bit longer and you'll see i'll i i do effects on this later where not everything becomes so flat here because it was kind of bugging me but uh you can see some of them are staying and a lot of them are kind of falling behind because they're just lagging they maybe they have a lesser speed you can see it looks like this very cool so how do you animate this because all of this is actually just animated in this node right so we have our position here and this is just to push everything backwards a bit you can see it's not doing much it's just pushing everything backwards and now we want to rotate and transform all of these shards well what we do is we can create a turbulent noise and just add it to our position it's a 3d noise and problem and let's just increase the amplitude so that's pretty much what i was doing but because this is moving all the time and it's rotating every time we the position shifts every time we get this rotation we're going to be getting a different transform different position that's why this turbulent noise is always switching the the offset like that and if you remember before way back here maybe not way back but here i did a rest position and that's the reason i did it because i don't want any rotation happening or transformations so if we plug in our rest and it's a vector and instead of using this position for our turbulent noise we just use this one you will see this is going to work now so now we can use uh you can change the frequency you can do whatever to push these particles and they're going to be kind of falling down like that there's they still have a uniform kind of rotation set to them and that we're gonna fix that very soon but that's that's gonna give us uh in the in the ballpark so now we want them to be moving as well up and down randomly so we kind of need to imagine each point needs to have a value of between zero and one so if you're zero stay where you are if you're one be pushed in some direction and that direction you know we calculated that direction before with our point velocity we can use this vector this vector and uh its direction to push it into the direction that it's actually falling from so if we just do that and we say well just you know we we're adding position here where are we what if we just add on top of that just push it in the velocity that you're moving and you can see it kind of did that by the the velocity well we can also normalize it just so it's everything stays here you can see everything kind of moved by one but it if it is going to move in the direction that it's falling from so if we pick this and multiply actually i'm going to do a constant here and now if i multiply this you know we're just going to be multiplying our speed so after we normalize it it's 1 and now we know it's going to be 20 but it's going in that the same direction so that's exactly what we want but we want to add a random value like i said before on each piece each piece needs a random value so we're gonna use a random node here based on the point number because these are packed so each point has a point point number if we put it into a random it's gonna output a value between zero and one so we can put that into a fit so this is our value we know it's going to go between 0 and 1 and now it's still between 0 and 1. and we can push it here into this multiply so now you can see what happened some of them moved more than the others because the the ones that have one are gonna be affected more and the ones that have zero are gonna be affected less and you can see that if i start stretching we're going to get a each point is going to be getting a random push based on this velocity and that's pretty much how i did that push the only other thing that i did was you animate you animate the these two values so so this is the velocity and you can just do this and you animate it oh it's saving the scene and you animate it going back right and you could just extend this and now if you look at it with our meteor and we do a little play blast here they're going to be kind of lagging behind and it's going to give you a feeling that everything is flying through the air and they have a different mass a different speed and that's gonna give life to our effect like that i think this one is even better better than the one that i did yeah i think that's look great yeah it looks good all right so now everything was still quite um everything works right at this point but they're still kind of rotating at the same time so i added another transformation which is uh i covered this more extensively in in the one punch man tutorial on how to do this so check that out um because i was explaining this in a lot more detail there but essentially we are doing a rotation a random rotation on each point and we are using this angle huh something weird is happening here yeah that's like uh i think that's a houdini bug right now that's happening but you can see it's doing a random rotation on each point and that's kind of what you want and you can animate this we put dollar sign by two i think you can kind of see now everything is going to be rotating maybe let's exaggerate it yeah too much i won too much you can see what i'm trying to do here i'll go back to my value which i think was animated before maybe it wasn't maybe i was yeah i think what i was doing is you can see now everything is kind of you can see they all have the same direction because of this transform and with this i just change the rotations slightly here so it feels more random all right i hope that wasn't too confusing and there was a little bug happening here for houdini but let's move on so we have our main meteor and now we have our shards all right i unpack everything here and i transfer the velocity because we're going to need it we're good where we're going to be emitting our smoke here i'm deleting the small parts because i only want to keep the big to medium parts and then use the small parts on the second sim i don't want to sim everything in one place so you can see i have three different simulations here they're all pretty much the same in terms of setup but they're just they have different scales so they need a bit of a different treatment to them all right i cash it out we have this happening right here and i blast everything here again because remember before i said i wasn't absolutely happy with how these shards were looking here they kind of became a bit flat you can see they they're forming a line so what i did was i added another stretch which is that same same note that we created here and i just added even more stretching and i removed the big piece here all right so now it feels more organic and they're not straight they're more stretchy as before before they were kind of forming a line and this was pushing everything a bit more all right but that was just like a side thing that i did and you could have done this here before you start going into this tree then i merge everything back i'm going to do a little scatter here just scattering what was i doing never mind so scattering color with attribute noise you get a color and then removing some points just so you get we got a bit more randomized emission but this part is not super necessary we do a pop oops do a pop sim like so and because we still have everything is still in place everything is everything has its velocity so the points are just going to be pushing into the velocity where everything is flying towards so you can you can see now how this becomes more practical right that we have everything set in place here before before we start doing any type of simulations and this pop network is a very simple one it literally has nothing it's set to everything is set to the defaults except i was using a different interpolation source just so if i set this to negative sorry to to none you we're going to be getting some stepping in the sourcing and that's happening because you know we would need a higher more substeps and everything and this just fix it so i think it was set to negative and i'm using the point velocity because we do have velocity this case and it's just going to be filling in the gaps here for our emitter you can see i'm using a negative velocity here and just a bit of variance just so it becomes a bit more random and more fuzzy at the edges and then another pop source uh pop force with the amplitude set to 50. all right after we have that we cache it out and you can see i'm caching three sub steps and i'm also here i'm using three sub steps and that's kind of important for our simulation so we have this is the the emitter we're gonna be using now the reason why we do emitters like this for a simulation like uh like this well it's gonna pop out like this is because it if you don't do this you're gonna get serious stepping issues in your sim so for instance if we don't do if we don't do this and we just use our points here let's see i'm gonna go a bit off-road just plug in here never mind this i'll explain this in a second just see if everything still works like this i'm just trying to prove a point so if you don't do the the yeah it's a bit slow if we don't do the particle simulation and in this case i'm also using three sub steps here so let's go to one sub step it's going to be a bit faster but yeah without using the particle simulation we're going to be getting stepping in the sim and you can see that stepping happening quite intensely right here and that's the number one issue that we usually face when we have fast moving objects and that's the best and the easiest solution to fix it so what we have to do when we get stepping like this we have to on this frame our emitter still has to be on this frame and maybe even on this frame and in our case you know it's just here so every frame that we do it's going to be emitting from that frame and without any sub steps in between that's what it's going to be doing it's just going to be emitting on each frame so the idea is what if we instead of just using this frame we use a source that is longer so now even though it's still moving you know from one frame to the other it's filling in all of the other detail and that's how we get rid of the stepping and that's how why we're doing this now like i said keep in mind we're using three sub steps now what does that mean if you go here on your houdini here you can see we are right now using integer frame values which means that we are moving uh per frame with every frame we go forward one frame and backwards by one frame if we use the integer frame values we're gonna be able we're gonna be able to access the in-between frames and you can see we have in between frames of our sim and that is because we we cached them we cached three in between sub steps and if you don't do this if you only cache one sub step your sim will still be stepping you can i can quickly show you on this example so if you don't have the in between frames you can see even though the numbers are changing here you can see they're changing but nothing is happening it's still going to wait until it goes from one frame to the other and that is because we have our substeps set to one and that is quite important when you're doing simulations more important than you think all right so we are back with our points here they're all nice and simmed now what you could sim your volumes like this you could and use the velocity to push all of your volumes backwards but that will give you a kind of a fake looking simulation you can do it in some cases it's going to work but in this case we need these particles to be moving through space and that's honestly the only way that i can think of to get a realistic simulation you cannot just fake everything like we were doing up to this point so what we have to do is get our point back remember that point we were creating the point that was created right here here that single point we take it so we do an object merge here and we take that point and we go down down down and plug it here and what we do we do the inverse of what we did before remember before we did minus b now we just say just use that position use the position of this point and this position of this point is now my position and that will put our points from here there they are in the center and it's going to push them back to where the meteor was originally it's like magic it's going to work like so and now we can use that to sim before we sim we need to create our pyro source in this case i'm using velocity temperature and density on this side on the other side i am calling so removing some points based on the age so i say if age is higher then this threshold remove the points and that's what i'm doing you can see here and the age attribute is being written by our pop network here out of it when you get your simulation you get the age attribute here it is and so this side is just going to be our flame and this side is going to be our pretty much our density and temperature and velocity so here i'm just creating a burn field that in pyro you use burn to create the flame field and i am yeah just creating a a burn field here with a volume rasterize and here on this side i'm creating uh the same thing but uh just using the density temperature and velocity merging it like so and that goes into our pyro solver now one other step that i did here is i have these pieces that are flying we did the same trick here grab that point uh did the position so now everything is flying again i did a time blend and the time blend is gonna help you can see although i think the time blend was not needed in this case because we have we were transforming this um you were transforming this geometry but the time blend usually if you don't have so if you don't have sub steps saved in this case we do you can see everything is moving but if you don't i usually just out of precaution i add a time blend so time blend here and i just time blend the position in this case just to be sure that we do have those in between substeps because they are again quite important i calculate the velocity here for some reason again or actually yes i was adding a kernel noise so you can see what this is going to do and by the way if i wasn't clear this side is being used for collision so plug that back in into collision the velocity uh without this velocity was very straight and boring it was just falling down if we add this it's going to add some some of that kernel noise goodness happening here and we want that to be on our collision because with collision you can with collision once you do this you can turn it into a vdb and you name it collision and you can also create a velocity vdb here and you can you we're going to be using both alright so another point that i want to take that i want to make with that those sub steps if we go back if we go back and we don't have sub steps on let's say you cache this right you cache it with one sub step you make that mistake that final mistake you cache this with one sub step where are they so we have this you cache it we do a sim and you can see in the beginning we still have some issues uh with the sub stepping but then later when uh this extends to its full potential like here with the issue is going to be gone also mind you i am starting with minus 30 of pre-roll time and that is exactly for those reasons so we have some pre-roll before our shot begins we already have a trail happening okay so and i think to illustrate this better i will put the global subset back to three all right so i will do a sim here just one sim it's going to take some time so i'll probably speed this up for you guys all right so we have a sim and you can see we are still getting that sub stepping happening and that is partially due to our collision not having proper sub steps so even though even though we are using three global sub steps here if our collision is cached with only three doesn't matter because it doesn't have that information so now if we don't cache this this will have all the sub steps that we need now you can also go here and just crash this with more more sub steps but in this case i'll just bypass this and do another sim and you will see that here if you look closely here you can still see the sub stepping happening and hopefully with the new collision now in that will be gone so where are we you can see it's already changing okay here see that see how smooth it is when it overwrites the previous uh pre uh preview like that so that's quite uh smooth now so that's how we want it to be and you can see if you don't do this properly if you don't do this setup properly you're gonna be in a world of pain because you will be hitting yourself on the head how can why is this so slow why why am i getting all the steppiness and that's how you fix it all right so we cash this out we do a little pyro bake i'm using flame and flame for everything for the scattering and for the fire let's punch this forward and here we go pretty cool i like it looks pretty good we're getting nice details here i will not be covering the pyro setup because it was very basic just sourcing everything in and like i said please do download the hip file and uh follow along with the file it's going to be much easier the only thing that here i am setting is sdf plus volume velocity so now we are using that volume velocity uh i can quickly show you if i go here so it's a bit faster collision let's put this to five you will see this is gonna start exploding now now our collisions are pushing in a lot of velocity in the beginning and it just creates that bubbly effect and it also creates well i like the trail that it does because it kind of creates more interaction and almost like it creates a wind field not a wind field but a wind yeah like a wind yeah it's a bit too much but yeah it creates a way of the well the the the collision is dragging the volumes behind it a bit better in some cases but uh it's yeah this is just too much it's just to illustrate that what this is doing you can see uh how this is pushing now everything but yeah this was set to 0.7 you just use it sparingly all right put that back for shapes i was just using some basic turbulence and disturbance using the speed field i really like this guiding that you can turn on actually no where is it they changed this just a tiny bit here it is speed speed back to one just to illustrate but the speed field is going to give you a very nice indicator of where of how the speed field looks like and i really really dig this it's very cool uh because it gives you a way of finding out the values that you need for your speed so you can see now if you go to uh what was it speed you can see all right everything that is red is going to be super affected everything that is not red is not going to be affected if you put this to zero and maybe this to one everything is going to be everything is moving super fast so now your disturbance is going to be applied everywhere but if you put this to 3 in this to 15 you're you're going to be only applying the turbulence on the hot areas and now you can visualize this before you would have to create your own visualizers with uh which would require you to go inside here and now this is a whole mess and now we go even more and you're like oh my god and now they they did this here for you it's very convenient and now you can use uh use those numbers to know where to put your values here i put it to 10 just to be even more safe i did the same for turbulence and that's pretty much it that's that's the main setup the small smoke trails have the exact same setup everything is the same uh the only caveat here is because i really want these to be a lot smaller a lot smaller if you actually was here so if you put this to density your your burn field is going to be big because it's going to use density as a coverage attribute and you don't want that if you're going to do this your your trails are going to be quite big again and you can see the difference this is how thin you want them to be and if you don't put this to burn they're going to be way too big you can see how thin they are now so this is a caveat and the other thing are the super tiny ones and the super tiny ones are same setup so we have the tiny ones cash them out i delete the big ones in the middle uh did that stretchy thingy i removed quite a lot of them randomly using this uh the wrangle so we have a lot less of them unpack scatter points so they have a lot of points on them and then i did a pop sim pop sim is the same as the other ones that's why there's not a lot to say about it pop sim look at them go so we have them doing their trailing uh push them back so they're flying do a vdb so here we do a volume from particles and a vdb so the vdb you name to density and this is where you put your voxel size and then volume rasterized particles you we are rasterizing just the density and we are creating density so it's going to be using points and p scale which you can set here and also i was adding velocity blur because in some cases they were they were still a bit steppy if you had velocity blur it's going to kind of blend and smooth everything and for these really tiny ones that was working quite fine you cashed them out all right very cool so that's the that's the main setup now i did want to show you another kind of bonus setup and that was happening here i didn't end up using it but you can if you want to you can make it work so we have our rock here again in the middle we did all the same tricks here with the points pushing it back here i made it a bit bigger and i put it into level so before it was following down like this diagonally and i put it back into a kind of a water level horizontal position then another point although this was not super necessary and i copied my emitter to it now my mirror looks like this it's not much but what it is is it's a sphere that has so first off we create a we create normals on the points and then we go here and here i just create the velocity so you can see i'm subtracting let me just first plug all of this out so you can create a new vector by subtracting your points minus a point you subtract them you create a direction that point is this this is the point that i'm using so whatever i do with this point you can see my direction is going to be changing also if i go further it's going to create a more a higher amplitude because the subtraction values become bigger so i put it right here right here at the beginning of our sphere the way the reason the way i'm controlling this is when you do a subtract and then you promote your parameter you can now you and you know right now this is just a single value but you can go here change this to a vector and when you change this to a vector you get x y z now on this point you can copy paste this parameter which is its position and you paste it here now this point this point here this position here is gonna be this point the position of this point i hope that makes sense and then you subtract everything and you get this so now we have our direction uh our direction vector but you always want to do some randomness to it so if you have a turbulence and i will show you right away why we are even doing this and how does this look so we have our turbulence if the color looks like this and everything that is black is going to be 0 everything that's white is going to be 1 and then everything in between is going to give you in between values so if you use this if we look at our vector and we say well multiply everything by this map so everything that is white you just stay as you are if you're dark like this patch become negative and that will give you some variation between your velocity and i did exactly that so if you plug this into your velocity you can see now how this is going to be corresponding to your map and that will give you some randomness i'm pushing it through a ramp because here outside once you use that ramp you can control your noise and based on that noise you're going to be getting different vectors well different vector randomization at least all right so i add some kernel noise i always like adding chrome noise looks like this very fuzzy and uh fuzzy nice this case i was just creating a mask and honestly you don't have to do this so i'll skip this part but uh you don't have to do it because i was clipping everything anyway so i was clipping so before i clipped i removed everything based on the color and then i clipped it in the back and in the front so this is our emitter that we're going to use for our sparks so i copy paste it to where my where where my centroid is of the meter so it's in front scatter points and now we're going to do a particle sim it looks like this i feel like i moved some values let me quickly find them all right so i did i did find the issue was here this multiply i forgot to plug it in like this so what happened was if i don't have that plugged in the sparks are not really going to be flying outwards they're going to be just flying straight like this and what we want is that outward motion where something happens it um let me let me find my words so if you have this meteor and this is flying very fast you kind of want your particles to be flying like this right so that will make it look like it's flying fast and uh it's going to have some some weight and velocity to it so that was the whole point why we were even creating this vector was to have everything from the center going outwards and if we don't plug this additional multiply you can see it now clearly how everything is coming from the center and it's going outwards all right so now if we do the same you can see this is the old one before the fix and now everything is going to be flying away from our sphere and now you actually get a sense of speed you get that cone happening here all right so now we have this cone and it looks pretty cool once you add sparks on it let me quickly show you how that looks like it looks like this and it works it's pretty it's pretty it's fun uh but what i added as a as another bonus you can use your you can use an rbd object here and just plug in your your meteor that's kind of rotating like this and once you do that let's let's do a quick flip book it's a bit annoying that it's not updating here it only does that once you go into positive values you can see that it almost it creates a fluid like motion to uh our particles because now they're actually colliding with the meteor and that uh you can also use that as another pass maybe you can rasterize the particles here and create a volume out of that all of our out of them you can also just use this as an additional layer of sparks you can do pretty much whatever you want you can see if they are actually colliding with the meteor and they're colliding quite well so you can also use this for sparks and you can use that for your kind of volume speed fields so that was another kind of tip and the rbd object you kind of need to reduce the bounce because if you're high on bounce it's gonna be freaking flying so imagine it's gonna be going in the other direction looks pretty cool though it's like a magical spell or something but it's going to be flying and then bouncing in the other direction so this has to be very long what if we what if we increase the friction i want to see if they actually stop they should be more contained now and actually stopping a bit more on the surface but uh yeah i think you guys can play with that i'll just leave the friction for now so yeah that was kind of the bonus spark setup and the sparks are very um this is kind of the default spark setup that i usually use houdini 19 does have a its own spark system and we're going to be covering that in a future tutorial but for now i just use the default one that i usually use which is i remove here we are i remove a bunch of points did a time warp here the just to get the in-between points and then re-timed it so it's much faster i guess uh we have to go here so they're much faster and then i'm using normal to copy our lines here so if you don't do this they're going to be pointing in the wrong direction p scale and color p scale is if you want to actually create a poly wire out of them then i resample them and add some flowing flow noise which can be a bit bit more because sparks are usually are not super straight there you go there's a cool little spark system all right that was quite a lot to cover uh i hope you guys were able to follow especially with that hip file now the only last thing i did wanna mention is how how do you render this in uh solaris and with karma so in order to render this you have to let's start with the smoke you have to import your smoke using the sub import and it's really simple you just literally you go because this is kind of a different context so everything you have here you kind of have to reimport back here it can be a bit tedious in the beginning but once you have everything here you can then again start transforming you can use your wrangles here again you can do a bunch of things and it's gonna stay in this context and if you don't like this positioning you can then just copy paste this again and kind of change it and so it's almost like you copied all the assets again and you can do an alternative version or alternative materials on this side so it's actually quite handy once you get into it so stop sub import and we do a the volume and you you just plug it here bam and that's gonna work and to make it super easy you just merge it with a light i know you're merging stuff with lights it's a bit let's do a let's do it dome light and this is going to be rendering here already and i i did use a hdr here so i'll use the same one like that and if you make it more dramatic you can see that's it super fast it's very cool so that's the kind of the concept here so you plug in your smoke you plug in yeah all of your clouds i'll include the cloud setup for you guys as well you include your meteor where is that lasting this is a bit annoying i'm still getting used to uh how to work around the viewport like some of the hotkeys are a bit different so you have your meteor shift r is to go inside and outside of your vendor you plug in your lights so we have a distant light somewhere here you can go inside of your light and change it like you like you would before with mantra and then i have another spotlight and a dome light they're very easy to control nothing super fancy here very simple you just merge everything together so once you merge it it's actually going to be visible here in the graph you can see you go to your scene graph and if it's not merged it's not going to be showing up here so if you're up here it doesn't know about it if you're here it's going to know about it so you plug in your clouds here as well you merge the clouds and now you have this you can use a light linker in this case i was using it just to add some extra actually in the end i wasn't i didn't use it but this meteor hdr is then only affecting the meteor and i'm excluding actually i was excluding this one never mind uh but yeah you can include or exclude you can see this is it has a checkbox or an x if you're including or excluding material library is where you create your materials uh here is the kind of the main smoke material and you can change that here and then you have to assign it so for assigning let's say this is our meteor here assign material you go you drag your meteor here and then for your materials you go if this is closed you open it up main meteor shader plug it here so now it's going to be linked and then i imported my camera through a scene import cameras or you can just create your cameras here as well but i just find it easier to animate it outside in this case and then you can bring it in here and then you have your karma settings uh you can play around with this and saber actually did a more extensive a very extensive in-depth overview of how to use karma so please check that one out so once you have all of that go here and then you shift r it's gonna now it takes a while in this case to render and i love this where is it the intel denoising it's so good in some cases it's a bit too strong but it's so good and saber shows you guys how to use that in comp later so you don't if you don't want the full effect you can still uh kind of do it in post and kind of do half and half if you want to but yeah then this is the this is the meteor uh so yeah in this case it's missing some of the elements so uh you would just add them like i showed you guys with the smoke you just add everything link the materials and you're good to go all right i think that's it uh for this for this tutorial was a a bit shorter than the other one but i feel like we covered quite a lot again for the clouds you know clouds very simple cloud setups uh these were small ones just so it creates an illusion of speed then you have your bigger clouds like that and i'll keep these setups in for you guys so you can play around and do some rendering on your own but uh yeah that's it that's that's that's everything that we have for you guys today i hope you enjoyed this tutorial um i hope you learned something new and uh see you guys in the next one alright bye you

Channel: Rebelway

Views: 46,470

Keywords: Houdini Tutorial, Houdini, SideFX Houdini, Nuke, Nuke Tutorial, VFX, FX, VFX Industry, Special Effects, Visual Effects, Hollywood, Simulation, VFX Tutorial, VFX Tutorials, Meteor, Meteor Tutorial, Urban Bradesko, Rebelway, Rebelway Tutorial, Rebelway Course, Meteor in Houdini, Space Houdini, Meteor Strike, Atmosphere Houdini, Houdini Tutorials, Advanced Houdini Tutorial, Basic Houdini Tutorial, Fire in Houdini, Smoke in Houdini, Houdini Smoke, Houdini Fire, Houdini Meteor

Id: 9wv88f1kvoY

Length: 63min 0sec (3780 seconds)

Published: Wed Dec 01 2021