Portal Experiments

Continuing my obsession with Portal (the game)


I’m investigating different methods of implementing the portal effect (continuing on from an earlier ill-fated attempt).

Method 1
Masking out the portal area and blending with view through the portal.

Method 2
Applying and clipping the portal view as a texture.

I still have a way to go, and there are a number of teething issues with occlusion, but both methods seem promising if GPU intensive.

Project here
Demo here

Incidentally, along the way, I’ve found a method of keeping items always on top. Great for debug rendering.