Do most games nowadays render reflection cubemaps every frame, or do they just do it once on initialization? I'm curious since I'd like to add refraction to a water shader for when my character is swimming around.
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Posted 21 February 2013 - 07:39 AM
Calculating cubemaps of the scene, 6 sides, every frame, including most or even all the postprocessing stuff of modern games, is very expensive. Therefor pre-calculated cubemaps (-> often only lightprobes) should be quite common on the current gen. When using cubes maps, the calculation is most likely stretched over multiple frames. There are other ways to calculate refraction/reflection, but the benefit of each technique depends on the engine you have and your goal (a small pond in a jungle or a simple ship on an ocean matters).
Edited by Ashaman73, 21 February 2013 - 07:41 AM.
My game: Gnoblins
Developer journal about Gnoblins
Small goodies: Simple alpha transparency in deferred shader
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Posted 21 February 2013 - 07:59 AM
That's what I was thinking too. For example, if the water is shallow and clear, reflection isn't really necessary and can just be a static cubemap if any at all, but then there's the ocean... I'd want reflection in the shallower parts, maybe. I'll try different things in my code. I've got some code written that'll render environment maps, so I could experiment once I have reflection and working finished.