10/24/11

Advanced Texturing and Lighting: Render Layers

This week we were working on rendering out turntables for our textured models.  Typically, this is where I fail to excel.  When rendering in a studio environment, this is where things get very complicated.  When you render, you do it in various passes.  That means that you render one diffuse color pass, one specular color pass, one shadow pass, one reflection pass, etc.  Once you have separated all of the elements in your render, you can then adjust how they look after the fact, rather than having to re-render your entire scene

video

However, things can get even more complicated when you start breaking up components in your scene.  Take the above video of Chimi, for example.  When I rendered her out, I had the above described passes, but also managed to split it up between objects in the scene.  Her hair has its own set of passes, her clothes have its own set of passes, her skin has its own set of passes, and her eye have their  own set of passes.  You layer these passes on top of one another in a compositing program like Adobe After Effects or Nuke, allowing you to adjust color, brightness, and shadows all after you have rendered.

video

With Ugly Ray, here, things are a bit different since he has particle-based hair using Shave and a Haircut. I had to render a separate hair pass and extract its alpha channel in order to isolate the hair.  It was a bit backwards, but it worked in the end.  All in all, it's not my favorite type of work, but it is necessary to understand how it all goes together in the end.

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