Stefan Röttger

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How can a volume be shaded?
Problem: We do not have an explicit triangle mesh that could supply normals for shading operations.

Solution: Lighting of the volume by modulation of emission according to the Blinn Phong shading-model: The surface normal is substituted for the normalized gradient vector of the volume. This effectively simulates the shading of iso surfaces without explicitly extracting those.

Head-light with ambient, diffuse, and specular terms of the Blinn-Phong shading model:

images by Christop Rezk-Salama and Peter Hastreiter

Advantage of shading: specular lighting reveals surface structures:

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