I’d like to use Blender and ray tracing to simulate a condition that occurs when a ring light is used to illuminate the edges of a small object viewed under a microscope. The ring light illuminates the edge of the object, which causes some reflectance back to the lens and also causes a bright outline around the object on the surface. Because the microscope has a large numerical aperture, this light is visible on the final image enough though the direct path between the illuminated point and the focal point is blocked by the object itself. Are there any suggestions on how to simulate these conditions? The image is a simple diagram of the configuration.
You could probably simulate this effect using a ramp on the diffuse shader set to ‘normal’
Then use some compositing to clean it up.
Another way would be a nodes setup, with fresnel and sub-surface scattering playing a part. Please post a picture when you’ve found a way, it’s an interesting challenge.