Maya 2018.6 - Render passes tutorial

hello I'm professor Matthew Rotella and and of this tutorial I'm gonna be going over setting up render passes I'm as you can see going to be using Arnold but the process is much the same for a lot of other renders no matter what you're using I'm going to be going over what render passes are in the first place how to set them up and then how you can use them to composite in a Photoshop or some other such program it's easier working with these things in in in Nuuk or or programs that at least it is for me now when I'm compositing and working with my animations but I'm gonna be just working in Photoshop today only because more people are familiar with Photoshop and and using it in that way but basically well Runner passes are is which I'll go over this first before I go over setting up your render passes mainly because mainly because setting them up is extraordinarily easy especially with a Arnold setup that we have here so so that when it comes down to that part it will really only take a hot second but what they are is it's basically your render split up into its individual components so I got a pretty simple setup here just a mug on a table and what you're generally your final image that's referred to as your beauty pass and yeah your full image with all of its components in it but in your render settings you can put out all of these a Ovie's or render passes then the terms are used interchangeably you can see you just your diffuse pass for example just your specular pass and then with and then you can go even further to see just your direct diffuse versus your indirect diffuse so you're in Decorah indirect refused a diffuse of course being the color that your objects inherit from other things around it so in this case like he'd get a little extra brightness on the wood near where the mug is because light is bouncing off the mug and hitting the table and you get that sort of warm brown color reflecting on to the mug from it hitting the wood and to this extent you can also troubleshoot where you need to up your samples if you're experiencing a lot of noise in your vendors like you can see that I don't really have a lot of noise in my direct diffuse it looks rather smooth but then if I look in my indirect defuse I have all this noise that I'm getting therefore to get rid of that noise I'm going to need to up might a few samples now upping your light samples can help you resolve some of that noise a little bit but not usually in your indirect passes usually upping your leg samples will help with you eliminate noise from your direct hit on the attribute but not your indirect same thing with specular I can get just my direct specular hits which you know don't have a ton going on there but then my indirect specular is going to have all of my reflections and stuffs there and similarly you can see that my I don't have any of that noise in my direct specular but I have it in my indirect specular so I can see that I may want to end up upping my specular my specular samples if I want a more high fidelity render until I'm satisfied with the elimination of noise I'll get into these shadow passes later but there's also things like the diffuse albedo pass if you want just a straight readout of the colors that your objects should have basically sans shading and there's also things like both of these have clear coats have big the wood because it's finished with the mug because it's okay because it has that glazing on top of it so I have a clear coat on both the shaders now there's also very useful utilities such as yes your ID Pass which I'll go over setting up the ID pass for the mug and because you can see I have just an ID on the table at the moment and the process is pretty easy anyway let's get into setting up all these different passes which are very useful because they allow you to to control entire attributes individually which if you're working with long sequences and you are compositing and a layered way in a program like nuke then you essentially never have to rerender your sequence again unless you have like major they basically never have to rerender your sequence again as long as you have the right friend or passes and as long as there aren't any like major changes to camera angles or edits but in any case let's go over how to set these up and it's pretty much drag and drop it on progressive refinement because I'm gonna end up re-rendering some of this and not the fastest on the computer that I'm working on but regardless if you don't do your render settings which is either here this little clapboard with the gear written go to Windows rendering editors render settings whatever makes you happy of course I usually just go for the the shortcut but you can look at all your various attributes and you'll see that there is in fact in a Ovie's tab now I have all of these turned on at the moment but I'll just get rid of all of them and you can see that the process of adding them is really straightforward it's just looking through the browser selecting the a be that you want and then telling it to go over into the active AVS list hitting the errors button so basically for anything you render a you'll likely want the main pass for whatever your main attributes are you're basically always going to want a diffuse and a specular pass and then basically you can take it from there I like to always have an object ID passed as well so I have some useful utility for easily creating masks and mats to edit objects individually and it's always handy so yeah basically be a you basically always want your diffuse and your specular Pass at the very least and you know what I'm gonna go ahead and make sure that I have that ID pass so I'll go over making the ID pass right now which in Arnold happens if you're going for the easiest way of creating it it happens at the it's going about it just applying it to singular shaders so I got AI mug right here which is in Arnold standard surface shader which as you can rightfully assume is for the mug and then here there's a Ovie's now I already have red applied to the table or the standard surface shader that's for the table so I'll use either G or B I for putting my mug into that I for this to be able for these ID passes or some people even call them disco mats because of how like vibrant the colors are I would recommend sticking to your standard three channels for the colors that you assign are G or B because that way you can always easily isolate those channels and therefore isolates those mats and various programs that you're using but in case you just got to give it a name so I d1 pretty straightforward and then I'll give it either G or B I'll make it blue so ID 1 and now it's blue all right now if I were to hit file or a render rather refresh render and just hit board if I were to look at my render passes you can see it's not there yet well I didn't sign it to the list yet so what I want to do and you'll likely see that ID 1 there is ID pass which is something different but they do not have ID 1 in the list well I have to hit add custom what's my UV name its I D what now if I hit create little plop it in the list and now if I were to hit refresh render and have it start cooking again and then if I were to start looking at my list you can see I have ID 1 in the list and my mug is blue and my table is right giving me a mat that I can easily use so yeah generally these are the passes that I like to stick with as like a baseline level there are lots of other render passes that have lots of utilitarian purposes but I'm gonna make a bunch of other passes so well I have a clear coat so I'm going to want to have a coat pass I have a diffuse albedo could be useful for something I definitely want to have I'm going to add my direct and indirect diffuse so I can have individual control over the Hat and again if you had if you had objects with subsurface scattering or you had objects with transmission those passes are useful to include I did not have those attributes on these shaders so therefore they would be useless and just rendered black but lastly I want the specular direct and indirect okay and this is really all the passes I need to get a good handle on things here so now if I were to now as far as getting these passes out of Maya which perhaps I'll lower my resolution for this because these renders we're taking not a long time but a lot longer than I particularly want to wait so turn it all the way down to HD 540 but regardless let's see here and now it's for getting them out of Maya which I actually have some previous passes that I could use instead but regardless you can check save final images so that when you render in and he go I were to go into my images folder and if I look in line temp folder it has generated folders for all of the render passes that I'm using now some of these are leftover folders from when I was rendering for different scenes but I got yeah you can see which ones are filling up the files which are the ones that I have any passes for for this render okay and we're just about finished here and that's that okay so now I'll go into Photoshop and well actually I'll just should open by default in Photoshop and the layer that I want to use at the bottom is going to be my diffuse layer because and I want it at the bottom because this is the way that Arnold shaders layer their surfaces and let's say I'll say use it as the Alpha Channel which if you look at the Arnold Sander surface a dirt surface shader documentation you can see that anyway let's get a new layer and then so you can see we have just our diffuse both our direct and indirect diffuse in the same layer and now if I wanted to layer things on top of it so first of all we have our specular which I could put it as just the specular but I'll do direct first so as transparency you can see comes in as this first but if I were to change it to linear dodge which is just add it'll add it'll add the pixel value on top of the pixel values for my diffuse pass and therefore now I've added my direct specular hit which of course if you're working like this you're going to want to be naming your files and also I'll make note that you can shuffle or you can combine all these into one layered EXR in your render settings if you your common and you hit merge a Ovie's it'll save them all in one EXR image as different channels on on your EXR which if you're using something like newt can be shuffled out into different pipes to edit individually but I don't think I don't think I think you can get a plugin for Photoshop I don't think Photoshop by default lets you do it for all the layers these that used to be the case but regardless this wave works fine - especially for individual images as my specular direct and then it's my specular probably should just have it as the Alpha Channel bring in that's my specular indirect so now I have my reflections add it into the shot which I can turn on and off now of course we have our code that will make up our the rest of it in which I you just have this as one player an alpha Channel there's the coat on your dodge and and because of the way that Arnold conserves it's a physically based rendering of energy so as you add up all of these layers onto each other as long as you don't add too many layers in it should always it should never start blowing out or exceeding your values but yet with this that's my diffuse my specular and my code which makes up all the layers of the surface shaders that I had built so now I essentially have my beauty render again which like I can just do a quick swap back to Arnold and see that that is in fact the case I have all of these details present in my photoshop render okay so now I and how is this useful well this gives us individual control over each aspect of what we rendered so for example let's say we wanted to turn our highlights blue and go into or something like that go into our HSL key and we can actually steward more in our indirect Speculator I'd say we wanted more of a different color in our indirect specular so I go my HSL and here it's much more obvious where I can adjust the hue and the saturation and you can see how just in my indirect specular I can add more of all sorts of colors I can really go wild with it or I can be subtle about it taking things I can darken it I can make it sound the right way to go about doing that but anyway yeah yeah so I can add color to it and I can use these passes to make masks like clipping masks to edit like just certain things individually so you'll get all of that big blooming alpha that I was getting earlier now let's say but I would say I want to make edits to my table here so what I can do which of course I can do is actually yes I can take my ID pass there's my ID pass which I want above my coat layer all right but yeah now that I have my ID layer in here what I can do is I can look at individual channels and create clipping masks that I can use to edit different objects individually and you can use these in conjunction with clipping masks that you can make by getting selections of your individual render passes as well but for now I'll just make some rather global changes so I got my red channel here which of course includes just my table because I have designed it to be so and now and now I can get this selection of just my cable and go back to my layers go down make a new layer and then if I hit create vector mask with my selection in hand it will make a clipping mask complete with what I have had selected and now I can delete urn well I could delete but I'll just hide that layer and now I can do things like paint like let's say for whatever reason yeah like I want my table to have more of like yeah like more of a red hue or maybe even I want it to be more cyan now I can go ahead and start painting and you can see that it won't paint over my mug and similarly it won't be over my background it stays contained to just my table and then I'll just go ahead and hit multiply and now my wood has been stained so yeah you can use all these passes in conjunction to great effect to have just enormous control over your renders now and I know that this isn't the generally what you're going to be going for with your renders but I was just trying to make some rather clear and obscene changes to my objects for the sake of being obvious for the tutorial but hopefully you can get the idea of how this gives you just each aspect of your render and makes it like completely tweakable to the point where you can like denoise and post and i mean if you got the right passes and you put them in the right program you can even retexture and entirely relight your your objects in post now that's a whole nother ball of wax but regardless you can do this thing and so be aware but that's basically it for render passes I'm gonna make another tutorial after this which is gonna be all about render layers now just to recap putting render passes on pretty easy it's just a matter of going through and just clicking them from one list to the other and having the the correct passes that you want from your object and then as far as building out your ID pass it's pretty simple you just go to whatever shader that you want to add an ID aov to so I had my mug shader just scrolled down until I hit the AO V section typed in a ID one made the color blue and then went into my render settings and hit add custom typed in ID one which I could make another one where I saved ID to create and bada-bing bada-boom and adds it to the list and if you ever need more channels than just the RGB out you can have it have an RGB if it sports it yeah it can have RGB a output but let's say you got that alpha channel from your various render passes so just to be aware with what you can do and just how powerful and all of these things are rid of ID - yeah which if you ever need to get rid of render passes of course if I have to hit delete all you can just bing-bang and now I just have that direct specular tompa okay so yeah that's about it I hope this was helpful hope you learned how you you understand how powerful render passes can be like I said they can save you from every rendering again which is a godsend so be aware and thanks for watching

Channel: Matthew Rotella

Views: 866

Rating: 4.5555553 out of 5

Keywords: Maya, Autodesk, Maya 2018, Tutorial, 3D Modeling, Texturing, Rotella, Matthew Rotella, 3d modeling, Animation, 3d animation, CGI, Modeling, Arnold, Rendering, Render Passes, Pass, Muti-Pass Rendering, AOV, AOV's, ID Pass, Matte, Photoshop, Adobe Photoshop

Id: 6HW6RHzN9CE

Length: 25min 45sec (1545 seconds)

Published: Fri Mar 06 2020