A little while ago, I posted a topic about combining multiple lights into a volumetric texture, then render meshes with the speed of a deferred renderer and the same quality of a forward renderer.
Since that experiment flopped [miserably], I'm reworking my lighting implementation but still trying the texture volume. I've so far rewritten my engine to support hardware instancing (to simulate a volume) but the trouble I'm facing is rendering lights to a volume. 3D textures seem to only include 6 faces rather than an area bound by 6 sides. Are there any rendering methods that actually allow for volumetric textures (something that I could try to access in a shader)? The closes thing I could find was rendering 109 2D textures but that's extremely excessive when I have the rest of an entire scene to render:
What I've done so far is combine a few lighting calculations into a single one. This has so far allowed me to render 34,000,000 vertices at around 47 FPS/0.021 MS but this is only with one light on pretty fast hardware. I imagine that I could draw my lights to a g-buffer and render more but that would cause me to render meshes before the lights (when what I want to do is the opposite; render a light volume, then render meshes).
Long story short: has anyone had success with rendering full volumetric textures at a decent speed?