Friday, 5 September 2008

Deferred Tentacles

Further work on the deferred rendering side. I finally found an example online using FBOs with a stencil buffer, and thereby discovered that despite using a combined depth-stencil renderbuffer it needs to be attached to the frame buffer object twice, once as a depth attachment and once as a stencil attachment. Sigh.

That done, efficient rendering of small lights via z-and-stencil-tested spheres works nicely!

Behold the scene, containing no less than fifty ickle lights, plus the large shadow-casting light from the player's avatar.

The majority of the screen is taken up by the final composite image. On the right, small sections show a sample of the buffers involved (yes, I don't even turn off my debugging chuffle before posting, I'm that lazy). Top is the SSAO term (very low intensity in the final image, as it looks pants). Below that are the lighting accumulation buffer, world-space normal, and finally unlit diffuse buffers.

Lastly, the image displays some filthy aliasing as the source render targets are only 512x512, violently scaled up to match the screen resolution. I should fix that.

Edit: here's a version using 1024x768 buffers throughout. Ouch, bye-bye framerate. Need to fix my absurd pixel shader usage methinks.

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