How to make EASY (but realistic) smoke and fire simulation in Blender | 2021

hi i'm chris bailey i'm a blender youtuber at seabaileyfilm on youtube you can find me there today i'm bringing you this tutorial with cg cookie we're gonna be burning stuff down let's get started [Music] now don't forget to check out cgcookie.com you can find a ton of amazing resources over there all right so welcome to blender now we're going to make some smoke so i'll show you it's a very complicated process takes a lot of steps you click your object we go up to object we go down to quick effects you click quick smoke boom and we're done so thanks so much for watching today's tutorial i hope you really enjoyed it and you learned a lot of cool stuff okay so but really i'm going to show you how this works i'm going to start off and just delete everything so let's go ahead and hit a and x and we're going to delete it all now the first component that you need to understand for any kind of smoke sims the same as fluid is you need to have a domain and that's going to define the region within which your smoke simulation is going to happen right because your computer is just not strong enough to calculate an infinite space so first thing we want to do is hit shift a mesh and we're going to create a cube so i'm going to scale this thing up on the z grab it on the z bring it up here we are now um it really it just needs to be a size that will will contain everything so sometimes it's good as well they're going to find what your camera angle is going to be right because then you know what's going to be out of frame and you can just like create your domain to fit just within the frame so you don't worry about rendering or simulating stuff that's not going to be seen so this is going to be our domain i'm going to rename this cube domain i'm going to create another object i'm actually going to switch over to wireframe view makes it a little easier to see in this step um and i'm going to shift a create now this could be anything right um i'll create a monkey because you know it's there and that's fun so here we go we've got our monkey now this is going to be the thing that emits smoke so the next step we need to do is we need to uh turn smoke on for both these objects so first let's click our domain and let's come down to the physics tab and we can have this we've got this fluid property here we can turn on so i'm going to click the fluid button we're going to go for a domain it's the same as with the fluid we can leave the rest of this for now all this is set up pretty well for us now the next thing is we click our monkey or whatever the object is you want to have emitting smoke and we're going to come here to the same tab click fluid and this object is going to be our flow right because the flow is the object that brings the smoke into your scene it's where it flows from now we have a couple of settings we've got the flow type which we're going to leave for smoke for now flow behavior now there's three options here geometry basically uses the mesh to create one burst of smoke that then kind of fades away right inflow allows the object to continually emit smoke and outflow is like a sink it like sucks the smoke up or gets rid of it helps it to leave your scene so we're gonna switch to inflow so this uh monkey will just continually emit smoke into our scene because that's what monkeys do have you ever watched national geographic you know that episode where you see all the monkeys and smokes like just coming out of them all the time trying to be funny it doesn't work let's go back to the beginning of our timeline and you can see immediately we get some kind of result we get this like shaded area um i can switch over to rendered view and we're not going to see anything yet but if you go to the flat shaded view as well you can start to see a little bit better i'm going to make my world i'm just going to brighten up my background so you can see stuff really clearly all right so now if i hit play you can see we get some smoke that emits and rises up it's got a nice little plume hits the top of our domain you can see how the domain kind of acts like a room that the smoke simulation happens in when it hits the walls it begins to react to it okay great now um we're really not there yet okay because there's some other things to consider the first thing is whenever you want to preview your smoke um you need to do it in a really stable way when you're in this mode right here we've just added the smoke elements and we're jumping around on our timeline and stuff it's going to start getting confused it's going to try and cache the simulation but it can start giving you weird results you're only going to get a consistent idea of what your smoke really looks like we're going to come over to our physics tab for the domain and if we scroll right down you get this little section here for uh caching the simulation now before you correct me in australia we say cash i know in america you say cash i don't know why you say cash but you do so just just take your hands off the keyboard don't leave that comment just step away step away from the computer okay cool we've got the frame start and end set for our simulation here and there's a couple of different types it's set to replay by default i find the most stable one to be all that could be better now in the more recent updates i haven't gone back and tested this thoroughly in with you know the latest version of blender but in the past the all type has been really the most consistent now what this is going to do if i click bake all it's going to create a file on my computer that saves the data for this smoke simulation now it's just going to read that data so now it's a lot easier for me to jump around on my timeline and i get a really smooth playback it helps me see exactly what's going on this is important to get the sim right now that we've got this set up you may wonder okay uh how do i get some extra detail on this because it's not quite looking right well the first thing to know about detail is just like with the fluid sim this little uh cube down in the corner of our domain shows us the voxel size now again remember a voxel is like in minecraft where you have the world that's generated every block is a voxel and it's it's like it's almost like a 3d pixel that's a good way to think about it it's a pixel in 3d space so each block represents one sort of pixel of resolution for our smoke sim in this 3d space if we make this cube smaller and smaller and smaller it means we're going to get more detail in our smoke you can see right here we get these like really jagged sections right so in order to have the detail we want we need to decrease the size of this cube so if we come up to our domain now every time you go and make changes when you're caching caching is you're gonna have to come down and free all that will get rid of that cache and allow you to make changes now resolution divisions if we change this from 32 we can go to 64 and bam you can see it's gotten a lot smaller now this will take longer for your computer to simulate so sometimes it's a good idea to keep it set to something low like 32 get your initial settings right and then crank it way up and run your sim overnight and then have a look at the next day just be careful it's going to take up a lot of hard drive space these sims can take up like gigs of space so make sure you don't have hard drive before you get started a couple of other things to add some extra detail to your your smoke is to one turn on noise noise will add in a little extra noise noise to the simulation so if i if i bake this again now you can see with noise turned on we're getting a lot of extra detail like it's it's breaking up a lot more it's curling out another thing you can do is you can turn on dissolve and what dissolve is going to do is it's going to make the smoke disappear over time it's fading off very quickly right it's just disappearing so this is a good way to create something like steam you know that one you want to have it to dissipate into the environment very quickly okay so we've got a really cool simulation things are looking good now how do we render this because if i switch over to evie for example you can see it doesn't show up at all we don't have anything yet in fact let me add a light i'm going to go shift a light sun turn this around a little bit and it's like okay right we can see suzanne but we can't see we can't see anything else but it looks great here why not well let's uh let's figure this out we're going to come to our domain now what you do is you add the material to the domain itself so not the object that's emitting the smoke but the domain because the domain becomes the smoke they give it that way it's easier when you're doing a fluid you can see it actually become the mesh of the fluid but this domain is is becoming your smoke so this is what we're going to add our shader to so i'm going to go to my shader editor i'm going to click new to create a new shader i'm going to get rid of my principle bsdf and i'm going to add a shader principle volume shader now one gotcha that you can run into is if you create it over here um you could select the principled volume shader on this side where is it at there it is it's going to automatically plug things up but it doesn't incorrectly it places it connects the volume into the surface input which isn't going to give you any result if i go back to my render view you can see we don't see anything still so you want to stick this into the volume okay that's how you're going to begin to see it now very faint you can't really tell yet let me i'll change my background as well so we're similar so you can kind of see so there we go so you can see that we've got something rendering here now all right now a couple of things that are important about smoke um if i move back far enough with my cameras you can see the smoke disappears and that has something to do with ev if we come over to ev's render settings and we come down to volume metrics you can see the start and end number this is basically how when you start rendering the smoking when you stop like how far away do you need to get for the smoke to stop rendering so 100 meters is what it's currently set to so when i it gets 100 meters away it's going to just disappear so if it's still not showing up come over here and check these settings you may have them down really low another thing is the tile size uh this is going to affect not only the resolution so the the quality of the simulation but this actually affects the quality of the render of that simulation so the smaller these tiles go the more detail we're going to get in the final render now again this is just with eb it's not as important with cycles cycles would just render it to its maximum quality one other setting that's really important in eb is to come over and turn on volumetric shadows and that will help create even more realism in your smoke because you'll begin to cast shadows with the the volume so you can see if i turn this off our smoke looks really flat you can't really see any of its in its definition but if i turn on volumetric shadows we're starting to get shadows cast on the smoke itself okay so great we've got some smoke but hey what happens if you want to have fire well thankfully it's not that much harder it's just one more step all we're going to do is come back to our emitter object go down to our fluid settings and where it says flow type we can just change it from smoke to fire plus smoke now if we come back over to our domain let's uh run our sim again and we don't see any fire how come well fire is actually it's a temperature thing and it's in here already but we just can't see it yet because our shader is not set up to deal with it so we need to come back over to our principled volume shader and we need to turn on a couple of things the first thing we want to do is set our color attribute we can set this i find it works really well if you set this attribute to temperature so if we type in temperature it will take the temperature of the smoke and because we've made it fire and smoke it's going to be hot right down here and it's going to cool off as it goes off now if i take my color and i give the color a fire color so something like red or maybe like an orange color you can see that this bit down here is going to pick up that color where it's hottest and then it's going to cool off as it goes now in order to get it to glow you need to use the black body intensity value you can see it's set to zero by default if i turn this up to one all the way up it's going to start getting really hot if i go to my render settings in ev i can turn on bloom as well that will help me start to see that really intense glow now the other thing to do is we can actually turn the temperature up so we'll take the base value that it's already calculated for the temperature and it will increase it um so i could turn this up to like 1500 and now you can see my fire is going to be so hot it's going to kind of glow white you can see it much better if we go to shader view you can see how it actually behaves like you would expect fire to behave now this looks like a pretty good sim it looks really nice even though we've got really low resolution settings we haven't really tweaked a lot of values it's pretty straightforward so if i wanted to get super high detail with this flame what i could do is come over to my domain and turn up my resolution so let me do that i'll free my bank i'm going to turn this all the way up to 128 and let's run this in and see what it looks like okay so that finally finished it took a while like about 10 minutes uh to go up to frame 150. let's have a look at it so you can see we're getting a lot of nice detail in these flames as they curl around the smoke itself is looking very nice now if you come over to the rendered view you notice it doesn't quite look as good well a lot of that has to do with the render settings so if i come over here and turn up my samples to maybe 128 and take my tile size down to two you can see it's starting to pick up a lot of that detail that we originally had now sometimes you can get some weird colors like you can see here if i darken my world a little bit we've got this like greenish tint that's coming through in the rendered vision version with evie and you can get around that by dropping down the brightness of your color for the temperatures or of color for the the smoke so if we drop this down a little bit off of um you know the highest point on the brightness so we bring it down to more of like a midway you can see it looks a lot nicer you can even get a nicer result if you take your black body intensity past one so if you turn it up to something like 10 your fire is going to really start to look quite nice sometimes this is a better result than just changing the temperature so you can see here in cycles it looks quite nice i've changed my absorption color to be sort of a brighter lighter red tone of the same red and you can see it really doubles up with the flames as the flames start to get covered by the smoke and it brings out the richness of that color and it can look really nice if you turn these things up now this works with any kind of model so you can use any geometry and throw on some smoke and fire and bam you're gonna have a burning object like for example this so i just took some i've just found a free 3d model of a house structure online downloaded it popped it into blender and stuck a smoke sim just like this one onto it and turned the fire up and there you go that's the result this is rendered out of evie um and not actually that many resolution samples this has turned down pretty low this is only 64 samples so um if i push this even further and get a much nicer result and if i render it in cycles it would look even better now in order to get things like the sparks all they did was put a plane in the scene with a particle system emitting uh some little emissive glowing cubes so really simple stuff all working together quite nicely to create some cool effects i hope you enjoyed this tutorial if you did hit that like button and leave us a comment let us know what kind of tutorials you'd like to see coming up in the future we'd love to hear what you think thank you again for watching i'll catch you in the next one until then have fun burning things down see ya [Music]

Channel: CG Cookie

Views: 49,344

Keywords: Blender tutorial, learn blender, CG Cookie, blender beginner, fire simulation in Blender, blender smoke tutorial, blender fire tutorial, smoke simulation, make easy smoke in blender, blender fire

Id: u_dL3JqXdp8

Length: 14min 35sec (875 seconds)

Published: Tue Jun 29 2021