Problem Statement

Current System uses global ray tracing to calculate reflection and refraction. However, it's very expensive. For complex curved surfaces, we have to go through expensive ray tracing and/or lighting calculation.

Solutions

Rather than using ray tracing, we decide to use cube mapping to present reflection. The basic princlple of cube mapping is creating 6 cameras around object and toward 6 directions. By pre-computing the images of these cameras, we can directly using these images as the texture to present reflection.

For our CSS 552 final project, we implement a new texture class, called cube. It can present reflection color by looking up textile in 6 pictures. Then we implement a new function to compute 6 pictures for texture_cube. It based on threads, so we can compute 6 pictures at same time. Besides, in order to make sample evenly, we implemented a new function to convert coordinate from rectangle to sphere.

Examples

Example 1

compare between cube mapping and ray tracing reflection. The size of picture is 300*300.

CubeMapping	RayTracing

Example 2

compare between 2 cube mapping. The size of first is 100*100, second is 300*300.

CubeMapping_100	CubeMapping_300

Example 3

compare between our cube mapping with cube mapping based on openGL. The size of picture is 300*300.

Our program	openGL

References

• Agu, Prof Emmanuel. "Computer Science Dept. cs543." fall 2013. Worcester Polytechnic Institute. slides. Februrary 2016.
• Kaushik, Sudhir R. "Environment Mapping - Introduction." 1999. Worchester Polytechnic Institute. Document. 2016.
• Shen, Han Wi. "cse5542-2013-spring Environment Mapping." Spring 2013. Departmen of Computer Science and Engineering Ohio State University. Slides. February 2016.
• Tze-Yiu Ho ˇ°Unicube for Dynamic Environment Mappingˇ± 2010 Visualization and Computer Graphics