Casting shadows with approximated object space accuracy by means of a modified Z-buffer
- 30 Downloads
Shadows are important in enhancing both the realism and the intelligibility of synthetic 2D images of 3D scenes. In order to determine which part of a scene is in shadow, numerous algorithms have been developed. The Z-buffer shadow algorithm and its descendants have proved to be both efficient and easy to implement. However, in casting shadows, the aliasing introduced by the Z-buffer point sampling is notorious. Therefore a new method that is based on a modification of the Z-buffer has been developed. This method deals with the aliasing problem but preserves the strengths of the Z-buffer algorithm. Moreover, as a side effect, the information stored in the modified Z-buffer allows accurate antialiasing of the resulting image.
Key wordsZ-buffer Shadows Annaliasing Computer graphics
Unable to display preview. Download preview PDF.
- Carpenter L (1984) The a-buffer, an anti-aliased hidden surface method. ACM Computer Graphics, Proc SIGGRAPH 84, 18:103–108Google Scholar
- Foley JD, Dam A van, Feiner S, Hughes J (1990) Computer Graphics Principles and Practice. Addison-Wesley, pp 689–691Google Scholar
- Haines EA, Greenberg DH (1986) The light buffer: a ray tracer shadow testing accelerator. IEEE Comput Graph Appl 6:6–15Google Scholar
- Reeves WT, Salesin DH, Cook RL (1987) Rendering antialiased shadows with depth maps. ACM Comput Graph Proc Siggraph 1987, 21:283–291Google Scholar
- Salesin DH, Stolfi J (1990b) The ZZ-buffer: a simple and efficient rendering algorithm with reliable anti-aliasing. Proc Pixim 1989 Conference, pp 451–466Google Scholar
- Salesin DH, Stolfi J (1990a) Rendering CSG-models with a ZZ-buffer. Comput Graph Proc SIGGRAPH '90, 24:67–76Google Scholar
- Williams L (1978) Casting curved shadows on curved surfaces. ACM Comput Graph Proc SIGGRAPH '78, 12:270–274Google Scholar