Compositing A&D Elements

Due to the redundancy available in A&D elements, there are several ways to composite them to yield the same result as the beauty render.

Here we outline two compositing pipelines in equation form. You can use these in Autodesk Toxik and other HDR compositing applications.

First we have the “simple” variant, which is simply a sum of the various result parameters. This version allows only minimal post-production changes to the overall balance between the materials. Its advantage is in not needing as many files, as well as working reasonably well in non-floating-point compositing.

Beauty = Output Diffuse Direct Illumination + Output Diffuse Indirect Illumination + Output Specular +	
  Output Reflections + Output Transparency + Output Translucency +	
  Self Illumination

Then we have the more “complex” variant, which uses the various raw and level outputs, thus allowing much greater control in post production.

Note that the raw outputs need to be stored and composited in floating point to maintain the dynamic range. The level outputs always stay in the 0.0–1.0 range and do not require floating-point storage.

Beauty = Level Diffuse * (Raw Diffuse Direct Illumination + (Raw Diffuse
Indirect Illumination * Raw Ambient Occlusion)) +	
  Level Specular * Raw Specular +	
  Level Reflections * Raw Reflections +	
  Level Transparency * Raw Transparency +	
  Level Translucency * Raw Translucency +	
  Self Illumination