Mapping Refraction in the Surfaces-tab
Norse Graphics
Posts: 0
I once thought it would be cool to create maps for the refraction-tab in the Surfaces, and 'bend' the light passing through a simple flat surface (say a plane). But there is unfortunately no option for this, so you're 'stuck' with geometry-based bending of lights. What I'm thinking of is simply using a grey-scale picture (png) and use this as a reference of the refraction-value. Sort of a cheap way to create lens-artifacts.
Just a thought.
Comments
I'm pretty sure I've done this with Shader Mixer.
Not only should it be quite simple with ShaderMixer, I can think of at least one reason why even Refraction Index should be mappable: lenses of eyes. You'd see everything in a "fish-eye" view if the refraction at the edges didn't compensate for that of the thicker center. So yes, refraction and refraction index should be mappable.
Yes, you could plop a map directly into the Index of Refraction (IOR) channel but since map colours don't go higher than one, you' end up wit a refraction that is lower than one. I've done the shader mixer network below that just adds one so that the IOR is between 1 and 2.
there may be a bug I'm not sure the vanilla Genesis should show as well (the plane is fairly close to Genesis, BTW)
You know, this is an interesting technique! You can really do some crazy stuff. If you use a base-number =,1 and as mentioned, add a map on top, and maybe use a multiplier-function of the map to control refraction/reflection. Then you might possibly get a very large refraction.
This is starting to sound quite interesting.
I think refraction works more like a projection on the surface rather then a true bending of light. That is why you see the objects behind if the surface is transparent. You have to use caustics to get true bending of light and that is not one of the 3Dlight-engins stronger sides. It doesn't help that DS4.0 has messed up the presets either, I don't know if it has been fixed in 4.5.
Cheers! Oom