I cant get refractive materials to bend a beam of light. I passed a beam of light (parallel, volume, infinite) right through an object that had an assigned glass material. Regardless of which refractive setting is used, the light beam itself passes through without bending like it should. (I also tried other types of lights, and light settings with the same result.) Scenes viewed through the same object are distorted by the materials refractivity; as they should be; however, the light beam itself slices through the object, and emerges unbent. See page 218 of the Bryce 4.0 manual for a picture that illustrates how a beam of light would be bent in the real world. I reproduced this scene in Bryce, but the beam wont bend. Anyone know why? I presume it has something to do with the way Bryce raytraces. Or am I doing something wrong?

Your assumption is correct. The light will not bend. This would require bryce to behave differently. If a light ray could currently do such a thing, when you shone it on a mirror in Bryce, you would see the light reflect off of the mirror...but it doesnt. To achieve the effect you are trying would require faking a light ray. apply a variation of the "green lit" preset material to cylinder, then where you wish the light to bend put a different cylinder and slight rotate/reposition it to fake the effect. Sorry thats all you can do currently BT

Thanks for explaining all this. I haven't yet had time to try the "green lit" preset trick, but I will try it.

Bryce will not "bounce" or "bend" light sources through or off of materials. You cannot, for instance, shine a light from the ceiling, onto a mirror, bounce off, and have it illuminate the floor. The floor will remain unlit. Try it sometime. That effect would be simpler than the effect you are trying to achieve, and yet Bryce can't even do that. In order to do this, Bryce would have to consider every possible surface in the scene as a light source, and check each to see if it is reflective, a light is shining on it, and that light would bounce to the surface in the pixel currently rendering. It's totally possible, but would slow down the raytracer tremendously and so is not a feature. To get these types of effects, you must fake it as BT suggests above.

Thanks for the explanations. Here's a mystery (to me), though: In Bryce I made a lense using a boolean interection of spheres. Then I assigned a high-refractive-index glass material to the resultant lense. Then I positioned a round surface behind the lense. Half that "rear" surface could be viewed through the lense, whereas the other portion could be viewed to one side of the lense--unobscured. The lense distorts that portion of the image that is viewed through the lense. I now realize that Bryce doesn't bend the light. How then does it distort the image as though the light from the image is being bent? By the way, the lense distortion is "proportional" to its proximity to the interior edge of te lense, just as it would be with a real lense.