An Image-Space Approach for Collision Detection Between Multiple Volumes and a Surface

Collision detection has been studied for scenes containing only polygonal objects (surfaces) or only volumes. With the evolution of the graphics hardware, surfaces and volumes can be rendered together, demanding new challenges for the area of collision detection. In this order of ideas, the authors propose the first approach for volume-surface collision detection, with GPU support. A mapping from surface space to texture space is established, such as each mesh fragment has a 3D texture coordinate. The volume-surface collision is tested in the fragment shader, verifying if a surface fragment is texturized with an opaque voxel. OpenGL® occlusion query extension is used to count the number of mesh fragments colliding with the volume. Since one surface can be texturized with multiple volume textures, the authors’ approach is naturally extended to discard collision between one surface and several volumes in a single pass, with a minimum impact in the rendering time. The authors’ tests reveal that collision between thousands of volume-mesh pairs can be evaluated in one second, showing that our solution is ideal for real-time applications.