Original subtitles

Hello guys and girls! Gleb Alexandrov here :) time to dive into the NPR tricks! post-processing

and other delicious stuff. and the first one is gonna be Denoising. first of all in order to use

and abuse the denoising algorithms we need to have Cycles set up as our render engine and we need to

see what we are doing, so the real-time viewport may come in handy. make sure to switch it on. the

3d scene here is very simple indeed, just a couple of light sources and a heavily stylized tree model

by Manu Järvinen and the orthographic camera actually, because that's also something that adds

towards this type of stylized look. we have talked about the orthographic cameras in the perspective

tutorial by the way. so the setup is primitive indeed, feel free to download the project files,

and now we just need to activate the denoising within the render settings tab. it can either be

Optix if you have an Nvidia GPU or Open Image Denoise which works on all kinds of hardware.

so why do we even mention denoising in the post-processing tricks video?

because it produces a pretty neat effect especially at the lower sample count, which i will

demonstrate in just a moment. i will switch over to Optix because i found out that it's a little

bit speedier, but ultimately that depends on the video card. and i'm gonna reduce the sample count,

that's the crucial bit. if you want the denoising algorithm to mangle the image in the artistic way,

we should set the render samples as well as the viewport samples to some super low number, for

example one. we can't go lower than that. so right out of the box we can see how the the edges

of the 3d model as seen in the rendering got much murkier and this effect is less prominent

uh... the higher we go with the sample count. so it's advisable to keep it at 1 if possible because

that will give the most prominent denoising effect. and it also depends on the resolution so if we go

quarter of the 1080p resolution, the effect will be even more pronounced. notice a smoodging effect

around the edges especially, when the sample count wasn't enough to produce a clear result.

that's what makes this effect very painterly and kind of beautiful. it looks especially interesting

in motion, when each new frame receives slightly different treatment by the algorithm of denoising.

now let's have a look at a slightly more advanced post-processing implementation of denoising,

based on the example of this amazing scene by Alex Heskett. Alex, thanks for sharing this amazing tip

on your twitter! so here we have the Cycles render engine, once again we need Cycles for it to work

48 render samples and in the Denoising tab here we have nothing checked on. that's because this

time we're going to use the compositor, but first let me render the image out, it renders

blazing fast even though it Cycles and whoa! right away we can notice firstly that the landscape is

gorgeous and secondly that we still have a lot of noise and all of this noise is deliberate.

having a grainy source is a precondition for using denoising in a creative way, so here i'm navigating

into the compositor, the Use Nodes checkbox should be turned on. to make it slightly easier i'm going

to enable the viewer node so we can preview each individual node and its outputs. now we can

Ctrl Shift and click on the node to preview its outputs, Ctrl Shift and keep clicking to

browse through multiple outputs at once, so the catch is that we should use the noise texture.

something like that, a simple white noise, that's as close as you may get to visualizing

entropy i guess :) and in a moment we'll use it to corrupt our render, to add even more

noise on top of it. so here we have the Mix node switched into the linear light blending mode

and we mix two outputs: our render and this white noise and we actually use a very minimal amount of

mixing, just 0.075 or something like that and predictably we need to use

the denoising that can be found under Filter, Denoise, so M to switch it on Ctrl Shift click

to preview the last node in the chain and bam!! we have made this whole thing instantaneously

much more painterly. it's a wonderful byproduct of the extra grain passed onto the Denoise node

which is basically the Intel Open Image denoiser, but implemented within the compositor nodes.

all right! lastly we can try tweaking the mix factor but i think we shouldn't overdo it, really.

as for me the effect is already quite pronounced, just look at this grass, it's unbelievable how

subtracting the the details, the grain... makes it look more NPR and more two-dimensional in terms

of some implied two-dimensional technique and if you want to take it a bit further you can wash it

out by using lower contrast, maybe color balance it add some glare everything that will take it even

further away from the sterile three-dimensional look. all right! thank you so much, Alex, once again

for showing us this implementation of the effect. keep doing amazing things ;)