Molecular shading

Finally some biomedical visualization, right? These images are work in progress for a few animations I am working on to demonstrate in a simple way some important concepts of molecular behaviour. This is from my work, as opposed to a personal project.

When creating the molecular shaders, I had two important ideas to consider. The first was that the form of the individual molecules was not very important. They should be treated simply and cleanly. I considered going as far as flat shading or toon shading, but decided against it in favor of a softer representation with a slight indication of form.

The second was that contact between molecules and their spatial relationship should be clear. Ambient occlusion is a great candidate for this, but I didn't want the AO to show form within the molecule, so I resolved this dilemma using an miLabel attribute on the objects, separate AO shaders on molecules, and using the idnonself attribute of the mib_amb_occlusion shader.

Finally I wanted to add just a bit of aesthetic interest to the molecules, so I gave them a slight sheen of a different color using a samplerInfo.facingRatio to ramp to lambert.color to achieve the effect. I'm rendering each of these components of the overall look in different render layers so I can play with the strengths of each.

For the lighting, I used a single very large area light with soft shadows and final gather that employed an IBL sphere mapped with a colored ramp. See if you can figure out the ramp colors.

Later,
Stuart