Prism - Z-Transparency vs. TayTracing

Hi,
Did anybody of you ever try to build a glass prism with a light beam going through it that is getting broken and splitted up into various colors?

I am at the beginning, and of course am already facing a problem, where I hope I can get your advises here.

The prism is supposed to be glassy, so transparent. I know how to get that. But then a light stream is supposed to go through it, getting fussy when going through the glass.

The weird thing here is that the penetrating light stream only gets visible when Z-Transparency is used. When switched to Raytracing, the penetrating part of the light gets lost.

Here the to renders:

[ATTACH]119338[/ATTACH], [ATTACH]119339[/ATTACH]
(prisma7_4_with_light_cone_wr_2.blend (575 KB))

Can anybody tell me what I am doing wrong here?

The next step would be:

  • breaking the light stream (IOR ?)
  • splitting the light stream into different colours (???)

Thanks in advance!
Robert