I’m creating a scene where I need to achieve the effect of light casting on a wall through textured glass, similar to this image;
I do not need to see the glass itself, the window in my scene is behind the camera and the effect does not need to be quite so dramatic as the example above. I just need to see the light casting on the wall with unusual refraction patterns.
What would be the best most efficient way to do this in Cycles bearing in mind that this will be an animation where items will need to pass between the light source and ‘window’ casting distorted shadows through it?
Looking at the original image, I find it to be very visually-confusing even if it is accurate. I think that what I would do in this case is to – thinking in BI terms here at the moment – emulate what might be done in a theater: create a spotlight that’s shining on the wall, and use it to project a blurry image. Or maybe you could do this with a (node-based) texture that’s on the wall itself.
I see no particular benefit to trying to actuallysimulate what’s going on in the real world: that would be very expensive and also very unpredictable. I wouldn’t even have the window (or something beyond it) actually casting light into the scene. No, I’d “think theater set,” and do it all with spotlights. Make it appear plausible so that it does not “draw my eye.” Get it done quickly and count it “good 'nuff.”