Today I finished the second part of the render layers tutorial and watched a different fantastic hour long tutorial which also went over render layers.
I learned:
To batch render all the layers separately one can go to render sequence settings and check “all render enabled layers” which will render any layer that has the clapper symbol on (the button next to the visibility). To have automatic names for each layer go to render settings, right click file name, and select combinations of the presets (‘RenderPass’, ‘RenderLayer’, etc) which will change the name depending on which render pass/layer it is! This is super neat. If one wants to create folders use the forwards slash / before the name.
To render all the AOVs as layers within an .exr, in render settings -> AOVs -> right click on an AOV -> select drive -> opens up default Arnold Driver -> check merge AOVs. Hmm this is what I wrote in my notes but after watching more videos I’m now wondering if doing this actually just keeps the AOVs from rendering out as individual files from the beauty pass… I’ll have to investigate further another day.
To customize the color after rendering, one can add an aiWriteColor node in hypershade, which acts as a switch between colors. Set one input as aiUtility (and assign a color to this) and make sure to assign which layer will affect the WriteColor node in its settings.
Some other useful tips: in render layers one can drag the ‘lights’ section of the master layer to a layer and it will create a collection with all of those lights (rather than manually adding each light!). While comparing render snapshots, one can right click on the snapshot and set it to be one half of a slider on the image so it shows half/half each render. Apparently one can change any value within a scene per render layer by selecting that layer -> right clicking on a value -> and select “absolute override for visible layer”. That is so neat.
I am still confused on:
I still haven’t been able to find a way to directly render the alpha of a shadow pass. I’m still getting the background HDRi in frame when rendering that layer.
Now that I know absolute overrides exist for render layers, I wonder if Maya has a similar functionality to Houdini with its linked values. I’d love to be able to link together the light samples for multiple lights. That would make things so much simpler.
Looking ahead:
Tomorrow I’m going to focus on exporting assets to Unreal Engine. I believe I understand the concept from my experience in Blender (baking textures, making sure models have transformations applied, baking lighting if need be), but I’ve never done it in Maya and I don’t quite know what specifics Warner Media might require.
I have a feeling this will only take one day to go over, and if that’s true I might also try some more test renders or look into motion channels.
Isaac Gazmararian 