Occlusion processing and smooth surface shading for fully computed synthetic holography

John S. Underkoffler, Stephen A. Benton, T. John Trout
1997 Practical Holography XI and Holographic Materials III  
Computation for synthetic holography typically takes one of two forms: the 'stereogram' approach, in which a large number of two-dimensional perspective views are rendered and assembled into a composite fringe pattern; and the 'fully computed' approach, in which the physics of light propagation from geometric surfaces and the resulting interference patterns at a recording plane are all simulated. Algorithms implementing the stereogram approach often generate their component perspective views by
more » ... erspective views by taking advantage of dedicated graphics hardware, capable of rapid rendering with hidden-surface removal and smooth shading. However, these standard computer graphics schemes for occlusion and shading are inappropriate for fully computed hologram synthesis. We describe an efficient algorithm that starts with a standard-form geometric description of the desired scene and generates a list of simple holographic 'primitives' that can be transformed into the final interference pattern by a simple fringe rendering program. The algorithm simultaneously performs the multiple-viewpoint equivalent of hidden surface removal, so that nearer surfaces and objects properly occlude those more distant, and surface shading, so that each object appears solid and exhibits the correct visual behavior in response to lighting in the scene.
doi:10.1117/12.271359 fatcat:js52sikabbdc3lhrizcpeo5wzm