Image-space volume shading method using topological information of surface-comprising voxels
Byeong‐Seok Shin · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1999
In order to shade a volumetric object, we should estimate a normal vector for each point on its surfaces. Normal estimation methods can be classified into object-space approaches and image-space ones. Image-space methods that exploit the distance from a viewer to visible surface points are more advantageous than object-space ones, since they require less computation and shade volumes rapidly even though the volumes are deformed frequently. However, they might produce topological relationship of visible surface and hidden ones. Also we devise the extended depth buffer for representing the topology of surfaces, which stores the distance to visible surfaces as well as that to hidden ones. It improves the performance of conventional discontinuity detector and computes normals on surface boundary with accuracy.