Unreal Path Tracer Basics

so these four renders are rendered with all different methods path tracing Ray tracing and Lumen and in today's video we're going to talk about the path Tracer while the path Tracer will be the longest render that you do out of Unreal Engine almost every single time there are some settings in the postprocess volume that are worth knowing to make your path tracing renders better so in Unreal Engine 5 I have my post-process volume selected and this is where you can adjust most of your path tracing settings now right now we're currently looking at the default Ray tracing in Lumen view by this lit mode but if we switch this to path tracing now we're going to get the noisy grainy look of the path Tracer but as we wait and as we render we can see this little bar behind all of my depth of field effects and stuff it is rendering out my scene but there's still a little weird thing happening with this shot if we go back to the lip mode we can see that there's not a lot of extra highlights inside this orb right here but if we kick it back over to the path Tracer we're getting a bunch of little white spots in here and on top of that we're seeing those white spots here getting a little bit right there these are something called fireflies and in rendering for 3D software sometimes this stuff just doesn't know how to interpret the light because it's really complicated long story short the easiest way to fix this is by changing the max path exposure by default this value is set to 30 but if we set this to one it's really going to clean up a lot of those fireflies in the scene now the second thing about the path Tracer and the post-process volume is this reference depth of field and reference atmosphere so if we look at the way it's being rendered right now the way it's kind of creating this depth of field effect and the atmosphere is using video game cheaty hack things and this is going way over my head for most rendering things but if you're just an artist that's looking for the best quality and best results possible I have found that turning on the reference depth of field and then also turning on the reference atmosphere is going to give you better results we can see here that these Reflections are a little bit tighter we can see here that the reflections are better here as well and the depth of field has a little bit nicer of a falloff because unreal is basically a video game engine it's doing its best to try and calculate some of these image effects in depth of field and atmosphere and fog are two really heavy intense effects to calculate so they'll find cheaty and hacky ways to do it but if you need the absolute best quality possible I found that with my path tracing renders turning these on can help now I do not recommend using the D noiser most of the time in unreal I have found that other D noising Tools in other software can end up being better so I will just turn this off a lot of the time and we can see it's still rendering but as we wait for this image to clean up it's really looking a lot better we can see these nice Reflections in this glass ball here we can see the nice Reflections inside this mirror ball here and the path Tracer is a really good tool to help get those really photorealistic renders but the problem is that this is still rendering it's still taking a super duper long time we're almost done we're almost done there's the render just like that I don't know how long that took maybe 30 seconds however long my face was talking but if you ever need to make this go faster what you can do in your viewport and the postprocess volume settings is that you can set this to let's say 128 and now it's going to go much much faster but we're going to get a ton of noise now if you do want to try and use the denoiser for still images you totally can turn on the noiser right there and sure that looks pretty good it actually looks really good for just still images but if you were to Denise this for an animation it will look really choppy and gross and kind of like weird AI so uh I don't recommend using the denoiser instead do that in other software like Da Vinci resolve or topaz laap or something like that now how do we adjust our path tracing settings for render so then we can get the best looking results possible out of our viewport cuz sure this looks good in our viewport but we want to be able to play this and post it on the internet you're going to hit your render button you're going to go to your settings for your render set all the settings that you need and if you need a more detailed Guide on basic render settings check out this video and you can get a more detailed explanation on that but we're going to get rid of the jpeg we'll set this to an E XR sequence set it to daab we'll do all the other stuff that we need to add our console variables our color output Etc now for rendering path tracing we're going to delete the Deferred rendering and instead we're going to add the path Tracer right here so the path Tracer is now enabled but we have to enable one more thing and that is the anti-aliasing so if we look at our post-process volume right here our samples per pixel if we multiply our spatial count and our temporal count this will basically give us this value as well so in general I've seen a lot of artists say like somewhere between 256 and 500 I'll start with 512 because it's a nice multiple of two and then I will also set my temporal spatial count to two if I have more Motion in my scene then I will increase this and maybe decrease this a little bit this will take a long time so you just have to be patient I will override my anti-aliasing mode and I will set my anti-aliasing mode method to none now from here I do want to render up my warm-up frames and it's basically like pre-loading the engine so then we can do all the fancy rendering stuff and if we have like more effects and stuff in the scene it can help some flickering so I will render the warm-up count and I'll set this to 240 and I will set my engine warm-up count to also 240 so with that said I could hit the render button and render this out as is we're going to get more detailed in path tracing in another video but for now this is a good General starting point understanding your post-process volume and how that affects the path Tracer I hope this video was helpful if it was let me know in the comment section down below questions comments concerns whatever else comment section is down there for that as well and I'll will leave you with the final tip eat one gr of protein per pound of body weight and you'll make some jeans goodbye my friends bye

Channel: Jon Jags Nee

Views: 13,592

Keywords: unreal engine 5, unreal engine, unreal engine tutorial, unreal engine 5.2, path tracing, unreal engine path tracing, unreal engine 5 tutorial, path tracer ue5, path tracer pro, ray tracing vs no ray tracing, ray tracing explained

Id: z-O5W1KdrDY

Length: 6min 22sec (382 seconds)

Published: Mon Jan 22 2024