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View Full Version : Faking reflections and refractions?

fxgogo
11-12-2004, 10:00 AM
Does anyone have any ideas for faking reflections and refractions, or a clever technique that will cut render times dramatically?

We have a project on the go that has scenes that are filled with glass. So as you can guess the render times are around 1 hour a frame and since we have 6000 odd frames to get through, you can see our problem.

Our camera in most of the scenes does no move at all, so I started to think of a way to fake the relfections and refractions, or optimise it heavily. The final result does not need to be totally accurate.
stew
11-12-2004, 10:39 AM
You can use reflection/refraction maps. In most apps, reflection apps are known as environment maps. I don't think many renderers support refraction maps out of the box, you will probably need a custom shader.
fxgogo
11-13-2004, 08:18 PM
Yeah those are going to be no good. As you say, it is the refraction that is going to be the problem more than the relfection.
rendermaniac
11-13-2004, 09:18 PM
Getting more than one level of refraction can be difficult. Sometimes you can use a distort type filter in 2D using the facing ratio to tell you how much to distort it by. However this is a hack and may not stand up if you need very specific refractions.

Simon
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