View Full Version : Refraction Index

Richard Hebert
09-08-2008, 11:40 AM
In LW 9.3 default refraction is 1.0 When I try to adjust this to anything other than 1.0 my 'glass' polys become opaque. Example, I have a glass canopy that is transparent at 1.0. I adjust the index to 1.05 while viewing the canopy from the side. The side facing the camera is transparent but the polys forming the glass surface on the other side becomes opaque. No radiosity is on so this is not a bounce issue that I'm aware of. Any thoughts?

Richard Hebert
09-08-2008, 02:32 PM
Does the refraction index feature work on a background image in 9.3 or 9.5?

09-08-2008, 02:51 PM
Do you have enabled Render Globals > RayTracing Refractions?

09-08-2008, 03:26 PM
Ray recursion over 1?

09-09-2008, 01:20 PM
The problem would be a lot easier to diagnose if you post a render.

Richard Hebert
09-10-2008, 05:26 PM
Sorry about the lateness. Ray refraction is on and recursion is at the default 16. The problem persists whether the refraction is higher or lower in value. Refraction works fine on an image texture, just wondering if it is supposed to work on a Background image as well. I've got a movie file that I have to superimpose the model over but need the cockpit to refract the image.

09-10-2008, 05:36 PM
just wondering if it is supposed to work on a Background image as well.
Those are the magic words.
No, it doesn't and it can't (basically because the background image is just "virtual" in the sense that it has no position in 3D space and this can't be intersected by rays).
You can just create a simple polygon and (using front projection) map your background image to it.


Richard Hebert
09-10-2008, 06:00 PM
Any way to get the camera to ignore certain objects when dof is not needed on a per object basis?