How to detect collision in webgl?

Question

How to detect collision in webgl, without using any library like three.js?

Answer 1

A simple approach it to do ray collision detection on the GPU. Checkout the following blogpost about the topic.

http://blog.xeolabs.com/ray-picking-in-scenejs

The main idea is to render the scene to a texture (using a FBO) using a shader that saves object ids instead of color. Then you can very fast do a lookup in this texture to see what a ray collides with.