index of refraction <1 in blender?

well. is there someone working on it? or Am I just not aware how to do it? Would be very Helpful to me, because I want to render some underwater pictures from a river bank. from the view of a fish looking whats going on “outside of the water”. If There was onone working on it… Could someone point me to the relevant code-section of the blender sourcecode? maybe I could provide a patch for it ^^. On the other Hand, This shouldn’t be too difficult to program, so if someone who already knows the blender API could do it for me I would be very grateful ^^…

Greetings, Tom

For what you want, just use an ior of 1.33, but point the normals away from the camera. Point the normals just as you would if you were taking a picture from above the water.

Also, please post these questions in the support fora.

In terms of physics, a IOR of <1 would require a ray to move faster than the speed of light in a vacuum, so I’d have to say that it isn’t possible. A computer could create a theoretical simulation of this, but that would require a little hacking.
The solution IanC mentioned should work… I’m just being a geek here. :slight_smile: