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- [David] With Blender 283,

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they have dramatically sped up

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the way volumes are calculated and rendered

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by combining a whole bunch of older settings

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into one more simplified automatic setting.

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Let me show you.

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First, it helps to actually be in cycles,

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where we'll be able to take advantage of this,

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and I'm going to be on GPU compute.

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And then if we open up volumes,

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you can see some familiar, but different settings.

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In the past we had steps,

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and you can think of steps as the slices

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and this is like the thickness of the slice

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for each one of those volumes.

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The higher the number, the thicker the slice,

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the faster it'll render.

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Thinner the slice, that is, the smaller the number,

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the more detail we'll get,

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but at the sacrifice of time.

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Now, let's go ahead

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and actually get some really cool volumes rendered.

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So, I'm going to take this cube here and I'm going to delete it

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and I'm going to hit shift-A and add a monkey.

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I'm going to hit space bar or F3,

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depending on what you're operator search is set to,

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and I'm going to type in quick smoke and hit enter.

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Now, if you're using different shortcuts,

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you can always come up to edit

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and just go to operator search.

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With this turned on, I can come over to my physics tab

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and I'm going to change my resolution to 48,

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so I have a little bit more in there.

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I'm going to turn on noise, so I get some nice verticity

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and little noise stuff happening.

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And under type, I'm going to leave it on replay,

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that way we can see it happening live.

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Okay, now with all of this set,

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go ahead and click on play.

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Depending on the speed of your computer,

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this might take a little bit,

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but you don't need a lot of simulation,

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you just need a little bit of it.

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Now, as I said earlier, steps are like the slices

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in a volume, whereas voxels or this little cube down here

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are like the 3-D pixels that make up this volume.

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If you were to turn off the noise and remake this,

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you'll see lots of little cubes

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that make up the smoke volume

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and that's why we have noise,

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because then it adds a layer of a little bit of distortion

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that makes it feel a lot nicer.

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All right, so now that we have ourselves

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a cool looking volume,

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let's go ahead and just click on render.

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If you want, you can move down the slide a little bit

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so we can appreciate the look a lot better.

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And wow.

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That is a smokin' monkey.

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Click on smoke domain

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and let's come up to our render settings.

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And if you haven't already, open up the volumes tab.

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There are two settings here that are important,

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the step rate render and the step rate view port.

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If you hover over it, you'll get a little tool tip

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that'll tell you how it works.

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The smaller the value, the more detail you're going to get.

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So, let's just type in 0.1.

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Admittedly at one, we're already getting

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quite a bit of detail.

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So, at 0.1, we might not be able to really appreciate

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any more detail and you can see how much longer it's taking

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to resolve this render.

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However, we can go the opposite way and type in 10

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and hit enter,

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and you can see how quickly this render resolves.

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Actually, it resolves very quickly.

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And that's it.

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Blender has found a way to automatically, quickly

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speed up this volume rendering just by typing in a number.

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Now, naturally, the bigger the step size,

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the worse your volume's going to look.

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You can see when I get it up to 100,

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this volume is starting to give me strange artifacts

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and it's starting to feel a lot lighter.

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Let's go crazy, let's go up to 1000.

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Well, it looks like you can't.

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200?

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Nope, we are maxed out at 100.

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So the best we can do is between zero and 100.

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Or not even zero, I think it limits us to like, 0.0001.

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Yeah, 0.01.

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None the less, if we just compare 0.01 to say, 10,

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you can see that yes, 10 looks a lot lighter,

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but it does resolve a lot quicker.

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So there's probably a nice partway point here,

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say maybe four or three,

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where it resolves very quickly,

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but it retains some of that richness in detail

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that we liked at 0.01.

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Now, this is a global setting.

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But you can come down to material and go to settings

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and change the step rate under the actual material.

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And there you have it.

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You've now found a way

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to dramatically decrease the render times

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for your volumes.

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Adding this to your repertroire of volume rendering,

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will save you a whole bunch of time.

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So definitely add it and keep playing with those settings.

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Until next time, this is David

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for Blender's Tips Tricks and Techniques.
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