Transforming Robot Production Pipeline Volume 9: Lighting and Rendering

OK at this point, we're now ready to render out our final images for our Transforming Robot sequence. OK so what I'm going to do is cover just a few Render settings that you'll need to come in and be aware of and make sure you have set properly. Now, these are some Render settings that aren't necessarily all that important whenever you're rendering just inside the Maya Render view, but when it comes time to Batch Render, these options become really, really important. So all of these should be found inside of the Render Settings. So whenever outputting, we, in one of our earlier lessons, enabled the Color Management features. So for viewing things inside the Maya Render View, using the output sRGB is just fine. But whenever Batch Rendering, if we're going to be using some kind of a floating point format, we want to make sure that this is set to a Linear sRGB Now speaking of a Linear format, this is where we start to come in and choose our Output format. Now again, we're going to render out in a High Dynamic Range Image format, so this would be something like an HDR image or an EXR. Typically, we prefer to render out in EXRs. File size is a little bit smaller and very, very high quality. If you want to be able to come in and maybe lower the file size of your open EXRs, you can maybe choose something like a ZIP compression. Now with an EXR, we have the ability to make what's called a Layered EXR file where, basically, within one file, in an instance where we have multiple render passes set up-- so something like this main pass-- what we could do is actually have all of these different passes written out as different layers inside of our EXR file, sort of like a layered Photoshop document. Now EXRs do give you this capability, but what we've actually found is that using a layers EXR tends to be pretty slow process, especially when it comes to compositing. Layered EXRs require quite a bit of overhead and typically, the more layers you have in your EXR file, the slower things become from a compositing standpoint because the compositing software has to sort through all of these different layers to get to the information that's at the bottom layer, whatever that may be. So for that reason, even though layered EXRs are possible, just from a pure efficiency standpoint, we actually prefer not to use a layered EXR. So we'll just render out a separate file for each one of these different passes. So to set this up, we can just come in here. And let's right click. Let's start by making a folder for the layer name. So that way, it will make a folder called main_pass. I'll add a backspace, and let's add, maybe, another folder for the Render Pass. There we go. So we'll have a folder called main_pass. Inside of that, we'll have a folder called something like specular or whatever we have these passes named. And then once again, add a new backspace. And once again, insert something like the pass name. So what they should give us now is individual folders that split apart these different passes. And again, I'm going to go this route, as opposed to using a single, layered EXR that has all that information in it. Now if we're going to be rendering out in some sort of a High Dynamic Range Format, again something like an EXR or an HDR, in addition to setting these options up in here, we also need to make sure we go into our Frame Buffers and make sure we have the proper information being output to our frame buffers. So we should find that over the Quality tab all the way down at the very bottom. Let's expand the Frame Buffer, scroll down, and right now this is set to an RGBA, four channels by eight bits. Now this is going to be fine if we're outputting something like a TARGA, a JPEG, a bitmap, but for a High Dynamic Range Image, we want to set this to four channels by 32 bits. So RGBA Float-- there we are. So that should now complete all of the major settings that we need to have enabled here. And now, really all that we need to do is set our output frames. So we'll do something like name, number, extension for the frames. And we'll make sure that we output the entire sequence, frames 1 through 144. Now if this is your first time rendering this out and you're ready to pass this over to your compositing artist, usually what I would recommend doing is instead of going ahead and rendering every single frame-- if you're on a little bit more of a time budget, you might want to start by maybe just rendering every 20th or maybe every 30th frame so that way, your compositor has a few individual frames that they can test and just have a chance to work through all the different layers, all different passes that you've set up. And that way, you can get a little bit better idea before you come to a really, really time consuming and resource intensive rendering process. Your compositor, based on this information, can give you a little bit better idea of whether or not you need some additional passes, whether or not the compositor is going to need some more information from you as far as shaders, passes, things like that are concerned. Again, just a little bit more of a safety precaution before you commit to a full render. Now once everything is good, you've had your compositor test a few of these frames, then we can come in and render every single frame. Also, going to be really, really important to make sure that we have the proper camera set to be renderable. And this is actually another good reason why it can be a really, really good idea to maybe test just a few frames of your Batch Render before you commit to a full sequence. I've actually fallen prey to this a few times where you set off your entire sequence, let it go over the weekend. You come back, check in, and then find out that you've accidentally rendered through the wrong camera, and so you've got to go back and do it all over again. Again, always good to sort of test and double and triple check these things before you commit to a full render. So once we Batch Render this, we should now get all of our different passes and all of our different layers separated by folders. So again, based on the way that we have the output set up, you can see I have a folder in here called main_pass, again, which is for my main pass render layer. So in this main_pass folder, now we get separate folders for each one of our different render passes, so my diffuse pass, indirect, reflection, things like that. So if I were to go into something like my diffuse pass, again, now we have an image called diffuse, or whatever my render pass is called, dot frame number, dot exr. And you can see that's exactly what we get here. So if I were to take a look at something like my MasterBeauty, for example, come in here and open up one of these frames, you can see we get something that looks like this. Now, this image may look a little bit dark. And that's completely normal. That just has to do with the Render settings we have enabled and the fact that we're rendering this out as an OpenEXR or any kind of a High Dynamic Range Image. So if we were to come in here and increase the Gamma to something like 2.2, you can see everything looks fine. And we can have full control over this in our compositing application. Now again, if you're a little bit unclear on exactly what this process entails, again, this is explained in quite a bit of detail in our Linear Workflow Rendering Strategies course. So if you'd like to see now how all of these different rendered passes are composited back together for our final sequence, then you can take a look at our follow up to this course which is Transforming Robot Production Pipeline Volume 10, Compositing. In that course, Chris is going to take us through the process of bringing all of these different passes together, sharing with you some of his techniques for really, really sweetening up some of these images, and also really just kind of giving you an insight into his pipeline, his thought processes, and some of the issues that he ran into, as well as the workarounds that he employed for those. And also, be sure to check out the huge selection of additional rendering training available from Digital Tutors.