Destruction FX | 3 | Pyro FX | Burst Source & Solver

in this video we're going to take the house that we modeled in the last few videos and that we blew up in rigid bodies and we're going to add an explosion to it and we're going to keep with the theme of keeping everything done in sops here with the sop solvers so we're going to use the pyro stop solver the plus side of that is i can keep everything separate and cache it separately the downside is that we won't get coupled behavior what i mean by that is the smoke effect in the bricks as much as the bricks affect the smoke it's a one-way behavior thing we'll have to simulate them separately but we can do some tricks to make them look like they're working together so what i'm going to do first off is create an explosion and then once we've done that we'll wire the explosion in here and get that explosion to kind of drive this simulation and then we'll kind of feed that back in to the uh pyro simulation to kind of collide with it so it kind of looks like both were happening at the same time so in order to do that i want to source my um explosion from somewhere so i'm going to start with a circle so i'm going to hit tab and type circle and i'm going to tap p to get up the parameter interface the parameter uh pane here and i'm gonna where's my circle let me just template the circle and just uh show the circle rather and template the building there and i wanted to lie on the ground so i'm going to put it on the zx plane here and um let's maybe move it back a little bit from the front there something we can position that a bit later um and then what i'm going to do is i want to create a point for the source of my explosion so we'll create a scatter node and for now we'll stick one point in there and i'm going to use a new system here for 18.5 and uh that's called the pyro burst source node if you hit tab actually and you look in the pyro tools you'll see there's a whole bunch of new tools for 18.5 um they're basically higher level tools that would save you building um stuff that you tend to build often i'll give you an example when we tend to do pyro we'll start with a point and normally what i'll do is um i'd have a particle system birth loads of points off here in the shape of the explosion i want and then i'd feed that into the pyro sim so a lot of these nodes will do that for us um some really interesting ones you might want to play with this with this are the burst source here and the trail source the trail will create trails and the burst will create sort of a big explosion we're going to use the burst source for this example but if you want to see them in action you can actually try out um oh where did we go there you can try out these guys at the bottom here and uh they're sort of pre-set ups of everything um all the bangs and whistles in there so you can see how to set them up and play with them so they're good examples to mess around with but um as i mentioned we're going to use the pyroburst source here so let's drop one in and see what it does for us so i'm just going to plug it in and turn it on for a minute and what you'll see it gives a little burst thing here let's just make sure that's inside the house yep that's going to stay pretty much inside the house so if i step forward you'll see it gives this sort of big particle burst oh there you go now the house explodes so i'm quite happy with the scale of that i'm going to turn off the templating of the house so what you'll see is if we drag the slider we get this sort of growing particles of multicolors and if we middle click we get a you'll see we get a bunch of attributes on these points like burn and temperature and we've got a bunch of settings here that can control this and eventually we'll feed this through into our pyro sim and um that was that will be our source and so let's have a look at how this might work so there's quite a few tabs here that we can deal with first obviously is initial size we can kind of have it bigger or smaller if we want and um i'm going to leave it for that at the minute and then we can sort of orientate the direction here you'll see it's kind of facing upwards in this y-axis so if i just change this to the x-axis you'll see it sort of faces along the x there let's leave that above back along the y and then we have a spread angle it's how much it spreads along that axis you turn that off and you'll see it's effectively a cone and then we spread sort of these multiple cones out and if you say 180 degrees you get a nice sort of starburst effect but we're on the ground here so i'm going to put 90 in and we can also change the roundness of the shape and you can preview this shape up here in the guide as a proxy uh with the proxy shape here and this sort of shows you the um a convex hole based around all of your um points there and again it shows you sort of the roundness or an idea of the shape and also the direction there you've got the little arrow which shows you the direction it's pointing in let's just turn that off for a minute so you can make that round more round or more jaggedy if you want and then we've got an offset here just to give you a variation of the different noises so if you've got a few in there you can just make sure you've got different shapes then down here we have number of trailings this is how many of those little cones we're getting let's bring that down to one so we can see what a single cone looks like there we go and um this truck this separation here is the distance between the points if i bring that lower we'll get a lot more points there so we get a higher sort of fidelity or higher resolution um uh sourcing uh points for sourcing uh and then we can adjust the trail length so if i shrink that or extend that we can kind of make this kind of shooting off little trail thing again i'd leave that for the uh trail source which is the other way of doing stuff which is uh if we just look in the uh rbd in the uh pyro here it's this one here the trail source that'll give you nice sort of trailing rocket bursts but um we're not gonna look at that in this tutorial so we've also got the trading thickness where we can make that uh wider or smaller or the cones in general so i'm going to kind of um let's just pop back let's put back in here the 250 back to the defaults um those are pretty good for down here now there's a another thing that we can do with this that's really interesting we can add some variations i've just got my explosion um happening on the one frame here so um yep let me just uh show you um what we can do at these variation site at these sides here with these options here what i'm going to do is make my circle big let's go sort of ten by ten and i'm going to put three scatter points in so we've got more than one point in there we can see our three explosions maybe make this eight by eight so a bit closer together there we go so they look um fairly similar so and what we can do is we can actually vary the inputs coming in so one way to do that if we have this on set uniform they all get the same sort of value they're all the same size of one if we set this to set varying then we can create some variation around that so at the moment you'll see we've got one and this variation of 0.25 if we put the variation up higher you'll see we get a much more randomness between the three choices that we get and obviously if you change the seed it just changes that randomness for you so you can create some randomness um like that which is pretty nice i'm going to put that to one so they're similar sizes they're not too big so if you've got lots of these you can have lots of different explosions of different sizes and things and again um we could maybe do this on the angle here so i'm going to do this to set varying and then i will sort of have it within five degrees of this angle here so um we're getting some i mean if you make that quite a lot you'll see it just tilts it around the axis so it's just five degrees around the y it's a bit of a wobble in there and then yeah we'll leave the uh spread angle i think and uh maybe just play with the offset something like that looks interesting so you can go in and put lots of variation here now um if we go to the burst animation we can also offset the start frame here so there you can sculpt the shape so here we can offset the start frame let's maybe make this start on frame three so as i jump forwards we'll see if we go to a frame three they all appear but again this is a useful one to add some variation in and um again we could use set varying and we could sort of vary the start time between three and you see we get a nice offset there or we could actually control this a bit more um in a more controlled manner and you can do this with all of these guys look we can set an attribute here as well so i'm going to change this to use attribute so it's going to expect an attribute on our points which will control this and that way we can specif specify exactly what numbers that we want so what attribute name do we use well if you hold your cursor over here you'll see it says in parameter start frame all in lowercase that's the name of the attribute we want but we can automatically make that with these nodes now on the right hand side here you'll see this dice icon if you click on it it makes a really nice attribute adjust float node for you and this node if your middle click creates that attribute for a start frame because we made it from that um button here it knows which attribute you want and you can change the settings if you want here now let me just right click and bring up the spreadsheet and we can see our start frame here is staggered now we've got um five six five and six there we go so we see two on five and one on six now the way this works is we're just setting a minimum value here that's this so the minimum one we're going to get is three and then we're gonna get any number up to plus three so minimum plus range so that's between three and six and we can see those values there i might put a four in here to have that go between three and seven and they've all got the same value never mind i'll just change the seed until i get something i like i want them on different frames there so is that one so we'll just change the c till we get one that we like they go four seven and six so we've got bang bang bang that kind of thing and the it's choosing a random number but you could get it to choose from a noise and uh we can either set all ways or we can add or subtract or multiply it to an existing number if the attribute was already there and you can change the method as well you don't need a minimum value which i quite like you could use min max values and it'll choose a number in between or you could specify middle value and plus or minus either side of that so it's up to you um and you can obviously change the distribution of that randomness here so it's quite cool that you can do that and as you see on you can do that for all of these properties here you can do set varying or use attribute so that's kind of cool i've got my little poppiness there so if you wanted to do that sort of line of carpet bomb type things you could obviously have obviously have each point with a a sequential number you could link point number for example to the frame number to the start frame rather and then you'd have that sequential line of explosions um i want these to be quite quick actually so we can adjust the frame duration let's make that three so they happen quite fast so you know what nice quick pop on those and we've got this other thing here we've got this outward expansion you'll see as they grow they kind of expand outwards we can increase that expansion outwards or decrease it so that's the kind of size that it would go to i'm going to have them come a little bit less maybe 2.5 and then we can have some directional expansion you know we push them in the direction that we specify up here in the direction so up towards the y there so we can stretch them a little bit and um if they scale up these two scale up according to this ramp so this is over the three seconds so it'll start off small it'll get up to scale quite quickly i mean we could move this um over here and have it scale up really slowly at the last minute so or you can control that how you like so there we go we kind of got this nice sort of poppy expensiveness there i'm gonna drop this back down to one by one so these will happen quite close together this kind of thing and i might just set this back to one for the minute just receive one explosion because what i want to do is go to the burst components here and just talk about the components it's creating and the components basically are these attributes and as we know these attributes are going to drive the simulation and at the moment we can just control creating a burn field and a temperature field and we can see those uh represented by these two tabs here so there's where we're creating the burn and here's our temperature now if we turn off the temperature field we'll see the burn field is represented by these yellow particles and the temperature was represented by the blue and if you add other filters they've got their own colors as we'll see as we go along but this shows us kind of the value that we've got in our burn field let me turn this on now the secret to good pyro is not having uniform stuff it's not just um a uniform emission of points here which we've got quite a non-uniform emission of points but it's also non-uniform values in the fields as well so we can kind of break this up and this is why they're colored so you can preview this for example we could add some noise and you'll see the black areas we've got zero there i don't really want zero so i'm going to bring the amplitude down to maybe 0.5 so the smallest will get sort of a 0.5 value of burn so it's just breaking that up and then we can change the size of the noise pattern here as well i'm going to make that a little bit bigger just to make it a bit patchy so it's patchy as it expands and uh blows up like that so it's quite nice to add noise i think to these things it really helps sort of give you that nice initial thing and we can also do some funky stuff here as well um we can scale it over the duration so if i turn that on what you'll see is as i drag through it actually scales the burn as it gets bigger so as we get really bigger here there's a lot less burn so it's mostly at the beginning and fades off if i turn that off it's just constant all the way through to the end here which means you can get really hot flames there i quite like the fade off that gives you that initial burst and then you can see the flames sort of die away and you can control that ramp here um using this you can make it fade off a bit three seconds is a very short space of time you'll see i'm affecting the ramp there let's uh scale over duration so yeah you can see i'm affecting the ramp the uh fade off with this ramp here so not only can we fade it off over duration let me turn that off we can fade it along the trailings here so you see along the length of each of those cones it's fading off to zero so the burns mostly at the middle here and it kind of thins out as the cone thins out again that gives quite a nice effect so i'm actually going to turn both on here so we start off with that nice burn and it sort of fades off as we go through time and this affects all the fields below here and including let's turn on the temperature and you'll see the temperature is represented by that blue field i'm going to leave the temperature fairly constant here i'm not going to add any noise to that we'll see how it goes so um the last interesting thing we can do with this thing with this um sourcing is in the output attributes here for example so here we can change some other stuff and we can add some noise to the velocities if i just turn on the velocities here you'll see they're just streaking out in the straight lines here which you might want but i want to create some turbulence some initial turbulence in here to create some um interest so i'll just turn this on for a minute and you see it creates some noise around those vectors there and again you can adjust the amplitude or the size of that if you want to um yep we can do the visualizer that's a bit nuts i like to do this one really but yeah so we've added some uh noise to our velocity there so we've got a very interesting sort of explosive thing here but we want to know how that might look so in order to see how that looks really let me put my scatter points back up to three so we've got these uh three guys working over time there so in order to uh preview this what we really need to do is um drop in our pyro sop solver now in what's really good about these sort of new high level nodes is not only they do they create these nice setups they give us these little quick setup buttons at the top here so this initialize button will set up some of the parameters here for us and you'll see the default was set uniform so if you choose set uniform it will do that if you choose use attribute it'll set up these buttons for you um i just i prefer not to do that i just choose the varying set varying or attributes as i go along but the video i do use actually is these quick setups here there's a few things you can do i'm going to choose the pyro simulation the source volume will just create the volume rasterize attributes whereas this will create the entire volume for you whereas this will create a single point coming in for you at the top of the node and they'll do various things so we want to create pyro simulation here and this will create the volume rasterized node and the simplifiable set up for us so this node here the volume rasterize if we middle click you'll see it's turning our burn and our temperature and our velocity fields into actual volumes so if we scroll through a bit we'll see the volume there and you'll see it's linked down here to our actual pyroburst source and that's how it knows which attributes to plug in normally you'd have to put these in manually and it's adjusting the resolution here from the particle separation that you would have done in this bit here the resolution so this is controlling the uh fidelity of those these um trails so if you want higher resolution you can just drop this particle separation down and you'll see you get a better definition of your points there that will slow it down a little bit the sourcing um but that's fine let's see how slow that's got now not too slow not too bad cool so um let's go to the pyro simple fireball here so at the moment it's using um if we turn it on and press play we're using the sparse solver as opposed to the dense solver um which means we're not actually using the whole box we're just creating the voxels where we need them to be and uh it does the resize around it and it's uh it can be a quicker in some cases but there's a really again a really nice new feature of houdini 18.5 and that is the minimal solve and the idea of the minimal solve is that you can fine-tune your look fairly fairly quickly and then when you come to do the final render you do a proper solve you can be it can be found here in the solving tab in the advanced tab here is minimal opencl solve when we turn it on you'll see um a bunch of things get grayed out and it takes a second or two to work now it's called minimal because it cuts down on a lot of these features so it can run entirely on the gpu which makes it very very quick look if i press play now you'll see it goes very very fast but there's a few things you'll notice first of all things are turned off things like this advection reflection that you probably want and stuff um like i said it does say minimal that's the clue so it can go fast but it's good enough that you can tune in your look and your shape and all the rest of it very very quickly which is the advantage of it um the differences are as you'll notice there's no cache here you have to go back to frame one and press play and it doesn't resize even though it's very very quick that's because it has to load everything into the gpu at the beginning and then it can play as fast as it can without having to load anything else in in or out and there's a few caveats to that um i'll just demonstrate those in fact let me put my circle here back to eight by eight so it's a bit wider we'll just wait for the source to catch up there and if i go to the fireball here let's just press play and you'll see oh that's not big enough so um so we can see that on an 8x8 circle let me just make the circle big and the first thing we need to do is resize this box it doesn't resize because it's loading all of these voxels into the gpu so we need to make this domain bigger so we can click on setup here and change it here in max size so i'm going to put something like maybe 35 30 by 35 and i'm going to treat the y boundaries closed below this will just clip the flames but that's fine because they're going to be eventually hidden inside the house just makes it a bit more efficient and we can play with the resolution there as well which we'll do in a minute and see now we can see how three explosions happening inside the box because i've got a lot more voxels it's a lot slower now be warned you're limited to the jeep the ram on your gpu your vram so if you make your size too big or your voxels too small you'll get an opencl warning error which is fine let's put .05 in just to see that there we go so this will pop up telling you you've run out of ram um i've only got six gig myself so um it's a little bit limited to the gpu ram that you've got but um it's fine enough to tune the look so you've just got to find that sweet spot of size versus resolution the other thing you'll notice actually it doesn't put out half the data that you would need for proper solve anyway so um it is really only for preview but that's good enough so let's maybe make this 30 by 30 just so it'll go a little quicker so it doesn't resize you have to resize it to the right size to make sure it fits in ram to begin with and then you can't cache either but there's um a few things you uh want to know as well so if we go to the sourcing tab here this is important and this is just for the minimal c opencl source uh the middle opencl solve rather so like i said it has to load everything in on the first frame and that includes the sourcing or any collisions that you might have and if you remember our sourcings here if i go to the spreadsheet are happening on frames four six and seven now here's the source frame range it's going to load in the first 12 frames of your source so if you make a change that's why it takes a second or two to do anything because it's actually caching up these 12 frames and then it's loading them all into the gpu so if you've got a lot of sourcing or heavy collisions and they take a long time to process it will take a while to do all those twelve frames so i'll show you what i mean if i put this to frame um let's just see where it started so we did four six and seven so if i um only load in the first three frames and press play you'll see we've actually missed the sourcing because we're only loading in the first three frames of the input here if i do four we should get our first explosion if i do six oh let's go back to frame one so if i do six then we'll get the two explosions and then if i do seven i'll get my three explosions but remember the explosion lasts more than one frame that's why we only get a little one there so i should put um they were lasting three frames weren't they so i should put 10 in just to make sure i get the full length and you'll see it takes a second there while it had to use the volume rasterize and cache that up but now we get our proper sourcing i'll put it back to the 12. so this is just to make sure that you capture all the uh you need to make sure that you get enough frames to capture all your sourcing coming in or your collisions if you're using them now the cycle length here it gets to loop um if i put maybe 20 in every 20 frames it's going to loop so there you go on frame 40 it'll go off again on frame 60 we'll get more explosions again the idea is that you can just keep playing here and interactively change these settings and just have it loop over and over again things will accumulate obviously in your in your box here the other thing you can do actually if you go to the edit menu in fact you must do this is you must turn on live parameter display during feedback so you need to turn this on when you turn that on it means you can live change these values so let me put 0.75 in the time scale and you'll see it has a direct effect there it slowed it down um there's some settings that aren't live things like resolution and stuff you have to wait to go back to the first frame so it can reload in the box but the rest of these settings you can do live so you see that slow slowed down the explosion there a little bit so this is a really cool way of tuning the look i'm actually going to turn off um let me just stop that for a sec so i'm just going to make enough of the cycles that it doesn't loop let's make the 120 and i'm going to come back up here and shrink my circle back to a small size so it's definitely within inside the house there so again it's just having to load up those first few frames and then we'll do our explosion there and we'll see my box is a lot bigger so i can probably shrink it down now let's maybe do 25 by 25 we'll see how that goes there we go we can get away with a bit more and look i can maybe drop the resolution down i'll say it's a little slower but then again i am recording video on the gpu in the background here as well as trying to process stuff so there we go now we can uh let me put the resolution back up the voxel size make that bigger so it got a little bit quicker for us so we're going to talk about some of these settings here so we can uh now we're in a position to fine tune our look let me try and make this a little bit smaller again just for speed so 20 by 20. there we go so if i go to the solving tab first of all we saw the time scale we can you know slow down the apparent explosion if i put it at point one you'll see it evolves really slowly and if i put it at three it should happen very quickly there you go missed it let me go back to frame one there you go things happen very fast i'm going to slow this down a little bit actually to give it a sense of majesty when it explodes there so um the next thing we can do i can talk about actually is this temperature diffusion if i put this up high you'll see actually blurs the temperature field and you lose all that lovely detail that we fight hard to get um sometimes if you get some artifacts you can put small numbers of this in to kind of blur and soften that out but tend to i tend to stop the resolution and try not to use that in fact the other thing is if you're displaying your pyro here is uh you must go to the display settings in the viewport click on the eyeball here or tap d with your cursor over the 3d view you'll get the display options here if you go to the texture options here you must turn off limit resolution i don't know if i hit the resolution the limit yet if you turn this off then you'll get the full glory of high-res sims in the viewport here otherwise it will limit cap it at that so if you are doing nice simulations you do want to turn that off to make sure you see everything all the detail in the viewport there so that's another quite important thing to remember so there we go let's see if that works a little quicker so um the other thing that's interesting here is this cooling rate this is how fast sort of the flames cool down as they rise so the way the flames work is obviously we have temperature temperature um is effect uh creates a buoyancy and that buoyancy then creates a velocity which moves it in the direction that we say and the buoyancy is driven by here if we open up by gravity i mean if i just change the direction of gravity to maybe off to the x there we'll see it shoots off into the side direction for us that's a bit odd let's make gravity minus one and um the buoyancy can make it rise quicker and slower so if i put a higher buoyancy and you see it rises faster and if i put a small buoyancy in it doesn't rise very much just kind of evolves around here a bit let's maybe put a slightly higher buoyancy in maybe 0.6 or something the other thing that can affect it rising is how quickly it cools down this cooling rate so if we put a high cooling rate in you'll see it bangs it explodes here but then it doesn't rise up so quick you know it cools down and sort of disappears faster if i have a very low cooling rate you'll see the heat stays within it quite a lot and it will keep rising a lot more as you see there you go it's much more effervescent it heats up a lot further and rises further so let's maybe uh coil this down by putting sonic 0.9 in i really want quite a quick explosion that cools down or disappears quite quickly maybe 0.98 let's have a higher number in there so a nice big bang and then i want it to kind of just disappear quite quickly and leave some smoke hanging around so the other thing we can do is this play with some temperature again this is the temperature it tries to achieve the reference temperature and this is the ambient temperature of the air around in kelvin so if i make this smaller you'll see it's a lot less hot and it doesn't burn so hot and as a result it doesn't rise so quick and look we are cooling it down quite quickly so it hardly rises at all but if i make that very hot then it's going to produce a lot of heat and even though it's cooling quickly it's still going to rise up quite a lot faster so you can make it much more flammable there kind of thing so some things burn a lot hotter and faster and you can raise that reference temperature and give an idea of that so you see a lot of these things adjust how quickly it rises up and also how quickly it disappears or loses its energy and that's kind of what you can control in this part so that's kind of my initial explosion there so maybe cool that down even more this is like 99 of the temperature over a second the cooling rate i'm not sure if it tells you that there but it is um next uh we can go to this flames tab so again we can control how far these flames live for at the moment they're kind of uh living today if i make this really small um they won't go up so high see the flames just disappear before they even go anywhere so again we can control how far the flames appear to exist for so i'm just going to bring that down a little so they kind of pop up maybe 2.5 so they're very quickly and then they disappear so you get this initial bang and then our flames kind of pop upwards now it's hard to tell the sense of speed here you can actually turn on frames per second if you tap d or again choose the eyeball here you can go to the guide section and turn on draw fps and just see it down there 120 fps so this isn't very quick at all well it is when there's nothing displaying as soon as i have to display the explosion it goes slow well the best way to get an idea obviously is to flip book it really um you know just to right click and do a flip book let me just turn the size off i don't like that very much and like the size of this window here and then we can see it in real time when we play it back we know this is definitely going to be 24 fps it gives us a sense of the explosion there so the just pops in very quickly and just burns up a bit faster let me maybe make that bit more buoyant so even though it burns out quick it just rises up a bit more as it disappears or something like that might be good so after playing with the flames life span here which you can shrink or grow um we can add some smoke let's turn on emit smoke and then we get some smoke um being emitted from those flames and see the smoke fades off over time and we can uh affect this now it doesn't look very good let me just stop it here whenever you're doing the pyro really what you need to do is add a light so i'm just going to come up here and just add a spotlight and initially we see we get some nice shading and it gives us a good sense of the noise that we're trying to uh that that we're getting in our smoke here so instantly that makes it look a bit better and more contrasty so we can adjust the smoke how it gets emitted here so the moment we're using this merge method so we've got some density already and we're going to add more density based on um this threshold so within the flame field so remember we've got a flame fill there in there so within the flame fills range between 0.1 and 0.8 we're going to map this so and uh at 0.1 so when the flames cool we're not going to add density and when it's hot above 0.8 we're not going to add density but in between those values we're going to add density so somewhere mid between those that's when the most density is going to go in there and if this is adding a value and there's already a value in the voxel it will just use the maximum value it won't although we could add it but you could accumulate too much density so max tends to be a slightly better option so we can control that but how do you know kind of the ranges that you might want for your fields well there's a visualizers that we can use if you go to the um if we go to the setup tab here we have these visualizers and look we can turn on show the flame field so if i come out a little bit let's go around this side we can see our flame filled happening for us in the scene there so yeah that's probably the best side to go let's put the lighting back on so if we zoom in there we can find out a range if you click on modify flame it brings up the controls for the visualizer here and you've got minimum maximum you can change the color actually you don't have to have black body you could do something like this uh the infrared and that you can find out your maximum and minimum values so if i can find out that my peaking red values here about one point oh yeah about one aren't they really let's go back and play the sim so the very hottest there is just about it is about one it's maxing or one point one point one one point two yeah about one point ones 1.15 something like that and then it's cooled down already by then so if you want to see the range we were um doing our smoke for if you remember that was between say 0.1 and 0.8 so now we're seeing the uh these are the ranges between those so the mid value would be where we're emitting most of the smoke so the mid value between 0.1.8 would be about 0.4 ish something like that so let's do 0.4 0.5 so that's most of the range that's where we're getting the smoke being emitted from so you can use these visualizers to kind of get a really good idea of what's going on in your smoke and the ranges that you're doing so let me just turn that off and we can also do one for the temperature come over here we can also see the temperature and we can also modify the temperature field again we've got infrared there so i can see that the temperature at this point is about point four so it's got quite cool and at the beginning there the temperature is um just under one about point eight or something we're maxing out on the temperature cool so that gives you some information that you know about your particular pyro sim and um you can obviously add more as you go along so if we look at the temperature there we can see that we're um it's getting quite cool by the time we get to the end here excellent so let's go back to solving here um so what i might want to do is have the smoke not being so much when it's cooling down so we'll put 0.3 here so it still has to be quite warm to emit the smoke there and i think i'll leave it at that uh actually no let's do uh yeah we'll leave it at that so we don't get too much smoke we'll notice it's fading off we'll fix that in a minute um but we get enough smoke here we can always come back and adjust this the other thing we can do is adjust temperature again we can add more temperature to the equation here so again it's adding temperature only where it's kind of really hot between 0.6 and 0.1 um we could bring that down a little bit and we'll keep adding temperature a bit longer in the sim so again we can keep some more temperature occurring a bit longer you'll see it rises up a bit higher if i put that to zero it'll keep adding it's not adding much it's adding 0.1 here but you'll see it just adds it keeps it going a little bit further up into the clouds there so let's uh maybe put this to 0.1 or something 0.2 and then we've got expansion here this is interesting this is otherwise known as divergence and this can get it to expand and contract and if i put a minus number in you'll see it kind of sucks inwards which is quite an interesting effect if i put a positive number in don't go too crazy with this one again you'll see it puffs outwards gives that nice puffiness to it so let's put a nice a bit of a bigger number in there and again there's a field driving this puffiness gives you that very mushroomy cloud effect so let's put two in for fear of going too crazy and again it's using the flame range here between where it's the hottest point six and 0.1 we know our flame went actually slightly hotter than that let's maybe put 1.1 in and then only where it's really the hottest so 2.5 let's go back to frame 1 for that quickly you see down the bottom here it puffs outwards so it's using let me just show you this quickly if we just pop over to sourcing again um this is the fields that we're actually using from the rasterize here look burn temperature and velocity even though it says density we're not using that it's bringing in zero but there's bringing in temperature that's the name that we call it here temperature and this is the name that the solver needs so you can't change this name but these can be custom names so you can bring in lots of different temperatures if you really want to and there's bringing in our burn but it has to be called flame and look it's actually using the burn again for the divergence let's create our own custom divergence field that's got sort of random divergence more related to our explosion explosions we'll see puffiness along the lines that we've blasted outwards rather than sort of this more mushroomy puffiness based around the burn field so i'm going to create a field called divergence so let me just copy this name and paste it here so now we're going to load in potentially a field called divergence but we don't have one we don't have a field here called divergence so again this pyroburst source node can make it for us let me go back to where we've got some sourcing i'm going to go to the components here and so i can see what's going on i'm going to turn off the bone and i'm just going to turn off the temperature if you click on the little plus you can make a third tab and let's create something we don't want density let's create some divergence and look it's given it the name divergence already so that's handy and you'll see it's fading off like we've told it to across the trail and across the duration and what i want to do is on my divergence is let's add a bit of that noise to it just to break it up again like we did before 0.5 so it's not totally zero i'll just scale up the noise again to 0.5 so it's just kind of we get these areas here it's going to expand a lot it's not going to expand very much here it won't expand at the tips which is quite good but mostly in the body there it will so let's see the effect of that now don't forget to turn back on your temperature and your burn otherwise there will be no pyro and we'll click back on our pyro solver here now we don't need to update the um volume rasterize here if you look we now have a divergence field and look it's filled it out for us because this is connected automatically which is pretty handy so um down here we have our diversions let's see if that's affected anything oh there you go that's made that a little bit more puffy it's certainly um made it more puffy which is kind of the effect that i wanted there so here's my divergence so if we add a bit more divergence let's set that to maybe 30 um we'll see that gets a bit more crazy because it but it'll only exaggerate it in the areas that we said there we go it puffs out a lot more let me bring this back down to 10 again so remember we've also got velocity i like to sort of mess up the velocities more i'm going to exaggerate my velocity here a bit more i'm going to set this to maybe 50 and the scale to 1. let's see the effect of that because remember we had all these random or slightly more randomized velocities along the trails there you go look that's really kind of stirred it up a bit so this is really amplifying those uh if you remember on the pyro salsa and the output attributes i added velocity noise now we're kind of seeing that coming through and spinning things around here let me set the deceleration strength to zero there see what effect that has i'm just um not making it too not too much not making it too crazy so we'll bring that in let's maybe add some more of the divergence back in because we're losing some of that because of this velocity there look that's looking a bit more energetic and puffy in the middle there get some interesting bits shooting out maybe let's have a bit more divergence the divergence remember is based along um these guys here you know base based upon the actual pyroburst source instead of just where it was burning before it's got a much more interesting initial explosion of some of these puffs coming outwards excellent right i'm starting to like that let's um we've done our expansion we've done our temperature and smoke and our simulation we've added a bit more of a divergence field um let's just drop the resolution a little bit to uh let's put 0.15 just to see we'll go a little bit slower but we'll see a little bit more detail up here in our smoke which is starting to look interesting i realize it's a little short now let's maybe 35 so it goes higher or um maybe we can just bring down the buoyancy a little bit maybe the buoyancy back to 0.6 just it doesn't rise up so much the smoke there so the next interesting thing is um here in shape um the look tab really is just for how it looks in the viewport we'll talk about that in a moment but let's talk about the shape here let's just turn off these noises so in shape it basically disturbs the velocity field and um to create all those extra noises for you otherwise you get this quite as you can see here quite a smooth looking simulation now the dissipation is exactly what it says on the tin it dissipates over time so again based on the temperature field here so that whether temperature's zero we're going to dissipate the most where the temperature is hot we're not going to hardly going to dissipate so it's just going to fade off this smoke over time i don't really want this smoke to fade off like that because uh if it was an explosion it's quite heavy so i'm going to really put that down low so it will eventually fade off but hopefully now we'll just get these clouds hanging around for all our 75 frames so they go they kind of disperse a little bit but they go that's kind of nice so next the funky one is this disturbance field let's click on disturbance here as soon as i turn that on you'll see it disturbs the velocity field and we get this lovely noise sometimes you get this shredding um some of the the issue for that can be is often that your um block size here your noise is too small or you um yeah your noise is too small you're trying to push this around too much so um we can affect that um quite happily here so um one of the ways we can do that is uh we can increase the block size so we're not trying to get such small shapes let me go back to frame one otherwise it'll just add it in there so if we look now we're gonna lose some of the artifacting again the hourglass filtering can help with this but i ideally the best thing you really need to do is just drop your res down and um really to see um if the artifacts go away because it's generally a resolution thing plus you're just pushing around the field a bit too much sometimes but as i increase the resolution there we're not seeing so much of those artifacts get away with it a bit more um you can when you're using the sparse solver if you do see it whereas it in the advanced tab here you can use hourglass filtering this is designed to help remove some of these artifacts but we can't use that with the minimum solve unfortunately let's go back to our shaping but that's fine so um we want to play with some of these densities so what it's doing is using this threshold field the density field and only when the density is below this value is it going to start to mess up our velocity field for us and it's doing it on a block based method we can do continuous so we're getting kind of a continuous um that's the continuous mode it's adding it sort of a noise in there again based on this reference scale which you can change to get bigger or smaller just trying to exaggerate the existing verticals that are in there so you can see you get quite a nice a nice little motion going those it just softens everything up nice and fluffy so if we put a uh a bigger reference scale in see the effect of that get different shapes appearing in our noise here so you might like that kind of look or if you choose the block base this is more of a fractal base type of noise we've got the size here if i put a big size in let's put four in you'll see the noise pattern that we've got and again we can change the we've got sort of three levels of noise here but you can add more if you want and uh you can change the uh roughness which kind of fades in those noise levels but there you go so it's a more of a typical of a kind of swirliness that you might get with cigarette smoke and the speed of which it evolves is generated by this pulse length and you'll see it's constantly evolving the whole time so you can change the sort of the shapes of your noises here now um remember it's disturbing of an existing velocity field so as soon as you start staring up it's going to keep stirring now what's interesting is we can use control fields to manipulate the stuff as well so if you look at this is set to speed we go to the simulation tab you'll see we are actually calculating a speed field up here and we can use that to perturb our noise so at the moment um if i we're at zero here we're gonna it's a linear relationship so at zero speed we're not going to get any disturbance and at two we're going to get a lot of disturbance i'm actually going to put that a lot higher because it's probably moving a lot quicker which will just stretch that ramp out so more it'll have to move faster for us to see some motion here so as it starts to slow down up in the air here we're going to get less of that noise so we'll stop it stirring up so much once it comes to rest otherwise it could look a little bit too energetic we have got a lot of energy going on there in there at the minute so let me put that up to a really high number and then only when it's moving the really quickest and we've got low density we're going to see those swirls so we don't see so many swirls in here because it's um we're cutting it off so in the real sort of um fastest areas that we get in it fast and thin areas so you can kind of fade things in and out with that let's put that to five let's put this block size back to um 0.3 i think that's quite a good size for this let's see just how that evolves for a minute again once we drop our resolution down we'll just sparse that should look quite nice so another thing we can do to break this up let's just turn that off for a minute is shredding so if you like the disturbance was affecting the density the shredding basically affects the flame the uh again the velocity field but it's using the flame it's using the heat the uh the burn field really to do that and again between these ranges point one and one we knew ours was actually about 1.1 so i'll just adjust that so again it's adding noise to the uh down here into the um flames into the velocity at the where the flames are the most down in the heat there rather than up in the cool density so we let's put a big number here like 20 so we can see an effect of that so you'll see it was quite smooth to begin with now um we should see a little bit of more jittery or noisiness going on in here let me make the block size a bit bigger see if we can make that a bit more obvious so there's a bit more noise want to look in the bright areas so if i put maybe 100 in we'll see definitely some shimmering so that you see here you can see um lots of more variation and sort of more of a swirly effect going on in there i might have to just drop the resolution so we can do something like that just so we can see that initial down there you'll see there's a lot more dirtiness and variation here especially on this frame 20. if i turn the uh shredding off we'll just jump to frame 20 again so it was quite puffy and we had all those sort of bright colors now it's much smoother see how it just all breaks all that up so let's maybe uh put this back to 20 or not not too crazy so it's not as smooth as we just saw on frame 20 but you'll see we've got these little puffs and it's broken that up now much smaller little puffs going on in there which is kind of good um if we add that to the disturbance because remember they're both affecting the velocity filled together you know that's going to create a different kind of initial thing to begin with because it's all shredded here it's not able to rise up so much and again it will give us a different feel for our um shred our disturbance to shred up and we get a quite a different look to that so it's really about fine-tuning all of these one at a time the turbulence itself just adds a general turbulence over everything let's just turn that on so um again it's based on the density field you see that using that as a control field um but it's uh the temperature is what's causing it so in where the temperature is uh below this range we're going to start to get our swells our turbulence in there let's put a high value in there so we can see just a general noise over everything it's not really dated by the thinness or the small or the heat or the density it just creates a noise over everything you see it just kind of bulges it all out in all different directions so make the swirls let's make the swirls a little smaller and then see how those look so again here's the influence field so when the temperature's below this value then this will kick in so as it cools down we start to see that turbulence in there again you can see we've got smaller swirls maybe let's make those smaller it's smaller again so the pulse length is how quick these swells change smaller numbers change faster or evolve faster so that we'll see in smaller details in there again depending on the swell size that you want i'm going to put that back to five and have this quite small actually let's punt put everything else back on there so let's run that through and see what we have got there we go that looks interesting so what i'll do is um i'll just do a quick play blast and i'll pause the video while this happens and we can see how that looks in a moment that has now um flip booked and if i run that through we can see we've got a big quick explosion and then we just turn into lots of smoke which rises up towards the end there and that's kind of the effect um i think i was after so um again i'm not i'm going to fine tune this a little bit more once we have our house in there so the next thing i want to do is to actually drive the house explosion with that and then feed back the house as a collision to this pyro here so it looks like it's hitting the walls so you know the two of them will hopefully look like they're a bit tied up together if you recall we've set up our house here for our rigid bodies let me just uh come down here and we've got our pyro burst source banging outwards there and this has got loads of velocities on on it and if you remember we actually created a piece of geometry here with some velocities on it um which we then transferred in after using a point wrangle um which worked out the impact for us based on basically the size or the magnitude of the velocity there and we scaled those up here so um we could pretty much do the same thing all we really need to do is plug in our burst source to this wrangle and that's going to give us some numbers but they're going to be different to what we started with so give you an example if i bring up the spreadsheet here let's just filter this list let me type impact here so we just see the impact and we can see the biggest the impact came to was about 15 000. so i plug in my pyro burst source now so let's see what kind of numbers we're dealing with with that so we said 15 000 so here we've got 186 000 so it's nearly by the order of 10. so we're going to have to consider that when we start doing stuff with this so in my uh impact scale here let me bring that down maybe to seven order of 10 let's do half let's do 500 or something because remember these are only like the highest ranges it's probably the mid-range is somewhere a bit lower than that so let me just bring that let's see where we go with 500 for now so we're still feeding in those attributes the velocity here and if you remember we're reading the impact down here in our little um vop expression down here we're reading the impact force in so let's see the change of that now i'm going to use this null just plugged into this third input here um oh there we go it's gonna run up to frame six for us rather than the rbdio if you remember we cached it out so it's not gonna quite be the same and look there we go oh and look you can already see the bits of the house are flying off in directions relating to that explosion there look we're getting them all in different directions so that's kind of working isn't it so what i really want to do is maybe um flip book this up quickly so again let me just run the flip book going so i'll just pause the video while that runs and then we can see how that looks there you go that's flip booked up and wow that's a little bit insane it's a little bit crazy i think my velocities are a bit mad so let me scale those down so um yeah let's put this uh maybe 0.08 isn't small enough let me put something like point five in so yeah my lights around the wrong way here let me go look through the light and lock it to the camera let's just come around the other side here so it just looks a little bit better when we uh come down the front what's going on with the spotlight there why is it going bright let's just lock that in again it's probably too close there we go let's come back down to the house so um again if i just run forwards we can see how um energetic our explosion is let me just give it a second to um jump in there and then i've turned it down to 0.5 and okay that's kind of interesting but again it looks like things are just being blown out maybe a little too far what's really nice actually if we look at the cache is um so on the first frame here let me just hide that a sec you can really see just turn the shadowing off you can really see sort of everything breaking up in their particular materials like the glass and the wood they're exploding out how they should so but unfortunately it goes a bit wild i then if the explosion would really blow them out that far away so let me maybe try this at 0.3 and uh i wonder if the attribute transfer will have an effect here and that'll just make things uh a bit closer so we'll just bring that force down to point three see if that comes down a bit so it looks a little bit more realistic for how far they go so we just have to see how far everything gets blown out there remember we've got some very light things made of glass and wood and we've got some very very heavy things again that's exploding it like crazy so i'll just try uh one last reduction maybe a tenth of the uh oh hang on a sec do you notice it's not actually updating maybe it didn't see the change there notice when i change this it's not actually removing the cache here so i must remember to go back to the solver here and turn off reset sim or rather click on reset sim you can actually turn the cache off if you go into the um advanced tab so if i go to the advanced tab here and open up um is it.network open up the dot network tab there we go you turn off the cache here and then it will always update without remembering but if you've got the cash on you sometimes it doesn't remember to remove it because um this was too far upstream really so there we go that's coming through that still looks a bit crazy but some of our bigger pieces aren't flying so far away so what we can do is probably rain this in by using a uh a clamp expression so we can do is clamp these velocities from being too insane so um what we'll do is we'll write a little clamp expression here to do that so i'm going to say v at v equals and then we'll say clamp and then we want to give it the original value to clamp so that'll be v excuse me where's um what's going on there so v at v and then we want to give it um the range to clamp it between so we'll create a channel vector here we'll call this a min range and then we want to give it uh let's also choose the max range so let's make sure we get all the right number of brackets in let's click the magic button up the right here to get our ranges here and again i want these to be the same to clamp the velocity so let me just paste relative reference so i'm going to copy the max x here and then paste that into the max y and the max z so they're always the same and let's try minus 9 by 9 then we're limited limiting this to um nine by nine in the velocity so it can go sort of a minimum minus nine and plus nine either way round but no faster than that so let's see if that um helps at all so still get the uh slower speeds but not the super super crazy ones so already we can see that's rained it in a bit so we don't know what kind of what ranges we need them doing it based on eyeballing it so there you go they're not so wild shooting outwards and we can obviously scale this up with the velocity scale but it's gonna hit the clamp for us so uh 9x9 looks pretty good shoving stuff out to a nice distance obviously not going to get stuff that um goes too wild away there so people maybe but 10 by 10 so again it hasn't uh let me hit reset sim because the cache didn't disappear and you'll see we're allowing things to shoot and blast out a little bit further there but it means a lot of things are going to get the same velocity obviously here at the top there we could put some variation in there so we didn't see everything clipping out that's why i kind of get a flat top here because all these guys are getting the same velocity as they hit the top of the clamp so we could add a little bit of noise in there look there's some pieces breaking away so that could be good for um what we want kind of want to obliterate the house like that excellent to see it totally destroyed there in our 75 frames so that should in theory tie up a little bit to our explosion there i mean if i look on the explosion here again we've still got this on the um minimal solve so we're in wireframe let me tap w to see the explosion there and we can kind of see this with respect to the house if we go to the house so um what i'll do is i'll just uh flip book that and see how that looks so i'll pause the video while that flipbooks there you go that's finished so if i press play we can see um it kind of ties together quite nicely we do get the feeling that explosion blew up the house what it kind of did the sourcing is what's destroying the house there and we've done a little clamp trick to um restrict the velocities in there we could put some randomness per piece in that clamp per point just to um vary it a bit so not everything was the same but i think it looks um okay at this point that looks pretty cool so yeah well i think i'm quite happy to do now is to actually write this cache out again i don't think i'm gonna change that sourcing so i'm gonna write out my cashier again so this will be version two house explode version two so i'll just hit save to disk so that shouldn't take too long while it caches up um the reason i want to cache it up is because i want to use its geometry in a moment um particularly to create a collision surface for our pyro solver here so it looks like um when it explodes it actually collides with the walls there so what i'm going to do is just pause the video while this finish is cashing out that's now finished cashing out so if i look at this null after the rbdio we should see our new explosion happening there yep there we go so that's um reading the cache back from disk so it also asked it to do that there so what i want to do now is um create a collision surface a collision geometry for this guy here so at the moment we've got it on the minimal opencl solve and uh here's the collider frame range and it's going to load in a collider for us before i do that let's actually turn this off let's turn off the minimal opencl solve if we go to the setup we'll see actually the collision options have changed and it's asking for a collision source this generally wants to consist of a collision volume plus a surface describing the velocities but how do you make these things well it's quite the clue's really there it says collision source so lucky for us there is actually a collision source node let me choose collision source node so i'm going to plug in the actual geometry out of my rbdio into the collision source node and this will make out the first input let me stick a null in there so out the first input here we get our collision surface with our velocities on it so the v attribute and then out of this second input here let's look at that one this is where we get our collision volume and this is uh more the important one so there's the collision volume here and you'll see actually at the moment it's not really uh working very well we don't have the top defined so that we can change that here with this resolution let's maybe try 0.05 and as if that gives us a slightly better a better res there there we go we can fill that in that looks a little bit better so um that that should work for us in this case and um ideally if you actually look on the silver here here we have the collision voxel size let me put this to 0.05 as well these should match up so this should always be sort of the same as that there and this should always be smaller ideally than what you're um solving otherwise uh you might get some artifacts now this can be quite slow to calculate as you saw i mean if i jump forwards in the cache to where it starts to explode interesting it's not doing the glass but that's fine the glass will explode anyway so there you go looks pretty looks pretty ugly let's maybe drop this to 0.04 that's fine it'll do as a collision we only really wanted the initial bit there so there you go see that as um the surface it will collide with so what you basically do is you merge these two inputs together like this let me get rid of those nulls and then we feed that into the simulation itself here so um that's going to try and calculate all those frames for me let's wait for it to go to frame six that didn't work that time so um we're using the sparse solve here so let me just go back to frame one oh i'm getting lots of errors that's really good let's cook in here 0.04 let's wait for all to evaluate again there we go so let me just step forward a couple of frames so this is going to be slow because this collision source takes um quite a while to process so what i'll do in a moment actually is cache this out to disk uh just make sure it's working first and then we'll cash out the pyro simplifiable as well at high res when we're done just to see what we get and that will take a bit of a while so what i'll do is i'll certainly stop the video while we do that so uh let's move forwards another frame it's not as quick as the um opencl preview there we go so as we come in oh look there we go we can see there's definitely some collision happening here you can see the shape of the walls let me turn on the template there but you can see the shape of the walls you can see the flames come through the window there it's also come through the walls a little bit because this is a bit hacky if you have a look my pyro burst source is actually coming through the walls so we will be birthing fuel and stuff through here but um if you look the house is kind of blown up at that point um the these don't collide with the walls here and um if i was doing a particle sim like i said i'll probably do it all within the same network so these things didn't interact more correctly but um this is a bit of a hacky way trying to do it all in sops there is a nice little trick that i um like to do actually is if you think about it the flames here are coming in um probably a little too early and if we scroll forwards yeah they're coming a little too early if we had a time shift node what we can do with the time shift node actually is uh here in the time i can minus one i'm just taking it back one frame so now where they see the explosion at that point that might tie up better if we kind of offset the explosion so it happens a little bit later that could often help fix this little issue it is a bit hacky but you know if i wanted proper coupled behavior i would spend the effort doing it all inside a proper a full-on.network so that the house does um kind of explode on that frame mind you if we do it without the time shift that's kind of believable i think a little trick i like to do with the time shift really is to put it on the source here so actually we're going to source that little bit later so let's try it here before we source we're actually going to source the pyro a little bit later than what it should that should give us a slightly different effect there i'm going to pause the video while i cache this up that's now cached up so um remember i offset the actual pyro source by one frame so let's see if that looks more interesting i think in this case i'll probably be all right not doing that because we want to see the house a bit of flame when it starts to explode so yeah sometimes when you see it looking a bit ahead of itself you can add a time shift there i'm just going to turn the time shift off in this case let me just disable that node with the yellow flag and see the sparse is a little slower if you would want to try collisions remember this is going to be quite slow to load in if you do want to try collisions with your um minimal solve let me turn the minimal solve back on here we need to go to the setup tab and look this is the collider frame range let's have it collide for eight frames now it's going to take a second because it's going to have to calculate all those eight frames there so it's going to take a little while to do that but then i should once it's done unless i change it be able to run the solve but only collide for eight frames after frame eight there it won't collide anymore because it won't load in you know those changes for us so we're gonna have to wait for that so i'll just pause the video again while that um catches up with us so that apparently caught up so um let me just turn off the uh display of the house there let me press play and let's see if this will load up in the gpu might not do because it's quite a high-res volume going through there so hopefully this will work there we go look you can see it colliding already there at the sides and now um you'll see the collision is not changing it's got that fixed shape of a house exploded around it so it's probably not the uh it's a bit quirky it's probably not the best but it gives us an idea what's going on if i just template that template the house itself we'll see what goes on so even i'm using the gpu for that so we've got the explosion inside you see it does definitely collide with the house there cool so um let's start to catch these things out so it's real slow to uh keep calculating this guy so what i'll do is i'm gonna add a rock geometry output let's stick that in it's a bit old school this but that's fine um let's give this a name let's call this um what's a good name to call it let's call it house call vol or something so let's call this um house call bowl number one so we want our frame range of our 75 frames here and to read that in i'm going to create a file node actually here and um what i like to do is i like to copy the parameter on the output file here and i like to paste the relative reference in the file so it's definitely reading the same thing and let's plug that in into our pyro instead and i like to give these a similar color so i know that they work together this will give me an error until we write something out but it's definitely going to write read in whatever this is written out and i'm actually going to do the same let me just copy these nodes just paste them in let's do the same for our pyro down here so again on this guy let's call that um we call that pyro version whatever it is so pyro version one power underscore version one there we go so we've got the same thing here that's all good and then this guy let me just make sure copy parameter on this guy and make sure this has the right expression in there because it's looking at the other rop so paste relative reference there we go so i should be looking at the right drop here so we want to cache both of these out so let me just save so again i'm just going to save this to disk and i'm going to pause the video while that happens and then in fact we'll tell you what i'm going to um yeah i'll pause the video while it happens right that now that has cached up if i click on the file node you'll see that's um loaded in these combined geometries for us if we run through we can see that's um moving through a lot quicker that means if we uh did now that we've got this set to uh the opencl solve let me turn that off let me turn the templating back on this there we go this should go a little bit quicker now because it um be faster to load that in without having to recalculate it so that'll improve our performance for tuning this um if we want to with our pyro like that so we can see that explosion ripping through the house now excellent okay so what i'd like to do now is um cash this out properly for that i will stop the video and then we'll come back once it's done so for this i'm gonna um drop my voxel size maybe let's go for five five um centimeters this is five centimeters this house is like a couple of meters high so 5 centimeters will probably be enough resolution um for this without creating too much disk space the other thing i must do actually is go to where is it sourcing advanced let's turn off the minimal opencl solve um and let's go to simulation let's turn on single projection and with the advection type this will give us more fidelity in the um vortices that we might see it just helps it look a little bit better we don't get that again with the um spot the uh minimal solve so again i'm just going to save and then i'm going to write out this guy to disk which is going to take a while so i'll actually stop the video for that and then we'll come back um once that's done so um is there anything else i wanted to do actually while we're at it um no i think that's good i think the time shift i don't need the time shift okay so yeah i'm gonna set that off so let's hit save to disk and uh i'll see you when that's done that cache is now completed and i flip booked it up to have a look and uh i'm not that keen actually on it even though i waited uh for it to finish what i'm going to do actually is tweak it now using the open cl solver the minimal cl solver just uh not have to wait a couple of hours for the full-on cache i don't like these shooty out little bits and i'm looking it's looking like the disturbance is a bit too much and maybe the um if you look at the initial flame there maybe the shredding's a little bit extreme as well so i'm going to go back and make a couple of tweaks but we'll do instead of waiting for the full-on solve we can do that quickly using the uh minimal solve so here i'm going to click on the minimal solve tab to turn that on and i might actually run out of ram because um i left the resolution really high so i want to see a similar res to what i was solving here actually is that going to work at 20 by 20 let me step forwards a frame and see if the little console pops up telling me i've run out of ram um i'll probably have to decrease the max size down to keep the voxels there because i think i'm just on my limit um yep it looks like i am so uh what i might do is to pause the video for a second and um see if that will just free up the memory for me oh there we go almost immediately up came the console tell me i've run out of uh vram so let me just put the resolution up high and definitely no i've got enough ram for that res let's bring this size let's cap it down to 15 by 15 and i'll probably be able to drop this a lot lower there we go let's see if i can press play now and uh oh that's better it's kicking in so um at least this is playing nice and quick now it's not going to give me what i want i've got those shooty bit ouchy bits um coming out too much so what i'll do is just stop that for a second and uh let's just come out a little bit so we can see a bit further so you've got to find that sweet spot for your ram and your resolution and your size um just so you can fit it all on your gpu ram so uh what else i wanted to do that's right i want to go to sourcing first and uh what i want to do is just bring down the velocity a little bit let's maybe bring this to a 35 let's put the deceleration to zero so we'll put it to 35 so a bit less velocity in there and i don't like doing more than one or two things at a time because you never know what's really affecting it um but what i will do is bring down my um disturbance a little let's stick this to maybe 35 let's see how that goes um what i'll do is i'll flip book that up and uh we'll see what it looks like with these settings so i'll just pause the video while i do that oh that just play blasted and uh or flip booked and uh ran out a bit from ram at the end there when we started the recording again but um let me just get rid of that error but um i can see that playing through and that looks a bit better i'm not getting such those crazy little things shooting out um [Music] let me just stop that for a second and um yes i think that's looking a little bit better i still think my disturbance is a little strong so um what i might do is go to the disturbance tab here and um i'm going to uh come down to the control field here let's bring that a bit lower let's maybe bring that down to one so um it will slow down moving a bit bit more what i might do is turn this remap on and let's just bring that down as a dent so it's only really going to disturb at the higher speeds and a lot less at the slower speeds that might bring some of that noise out of it so um i'm just going to drop my resolution a little bit there let's put that .06 because uh maybe make this 30 in height because i'm losing uh ram there let me just point point i put 0.05 similar to the res that i was assuming so after that one last change um i'm going to flip book it again this is a lot quicker because obviously i'm working at similar rares to when i cashed it out and to do a proper cache took a couple of hours whereas this is taking uh not that long at all um it doesn't like it when i'm doing the recording at the same time i'm going to pause the video actually and i'll flip that up and uh i'll pause it when when it's done right that's now um flip booked up and running through that only took a few minutes um i'm quite like looking like quite liking the look of that now so i think that's worth me um spending the time to cash it up properly so i'm going to go back to my setup here and put this back to .05 in fact let me go to the solving tab and not turn off calculate speed we're using that let's turn off the minimal solve so it won't run out of opengl errors and i don't need to resize the box because it's going to automatically resize as we saw before so yep i think i'm happy with all of those settings i'm going to get a nicer noise now so um what i'm going to do is actually cache that up for real so i'm going to let that cache run this time and then what we'll do is we'll come back in the next video and we'll look at how to render that so i

Channel: Houdini

Views: 4,838

Rating: 5 out of 5

Keywords:

Id: -OJi-9YOY9M

Length: 85min 1sec (5101 seconds)

Published: Mon Nov 23 2020