i have a problem on how to make a prism work on blender render. but every-time i tried it ends with a shadow being a shadow. i mean, i wish there was a way to make a prism work on render, NOT a cycles.
look.
if you want nice results try it with yafaray or luxrender !
happy bl
Internal render doesn’t support caustics at all. If you really want to use internal renderer, you can model caustics as white plane with alpha texture. That’s will be crazy, but seems the only way to go.
To get differential refraction of various light wavelengths (which is what causes the rainbow effect) you need a renderer that treats white light as true white light, i.e. composed of many wavelengths. It will also need to take into account the specific properties of the refracting material, not just IOR (though that is very important). Some real-world materials refract different wavelengths at differing amounts than simple IOR can allow for (which is why modern lenses use different kinds of glass elements). The Blender Internal renderer does not do this at all, instead treats every ray of light as a simple linear path for the purposes of raytracing. That’s OK for basic refractive visual displacement but cannot do full wavelength-differential refraction, nor can it provide true caustics (the rainbow from a prism is a form of caustics).
then if its a form of caustics, then i had to make the entire blender render in cycles? bummer. you don’t know how long it take to load frame after frame. i was trying to make a prism puzzle with crystal prisms that conduct to light and refract the lighter onto other crystals so they can activate the far away power crystals. if the light beam are caustics, then i should have rethink this trough. as for the myst style game, i dont know what the islands would look like or how will the crystals go.
BTW the cycles wont do any good 
it was suppost to be a first gamemaker engine myst game.
I hate to break it to you, but games do not use true refraction and especially not the kind that would allow for a true prismatic effect. Instead it is all faked, very cleverly, of course, but in a way that doesn’t strain a computer or game console. True refractive raytracing would be horrendously expensive in terms of machine cycles, slowing to a crawl any game that tries to use it in real time.
well it would seems to me that i would choose the light beam using the halo of spotlight. that way it wont be impossible to know the difference… i think… i was thinking of posting frame to frame. like myst games have. you see i need to know all the puzzles for the myst game. like the crystal sample. i mean you click on image and takes you to different areas and views.
Even when rendering stills for a Myst-like game, I doubt true refraction would be used, as it would be difficult to control exactly and is really much simpler to fake. Something like colored spotlight cones as you mention, or even image-textured planes, would suffice, and be much simpler to produce & faster to render.
we need to work together in order to make the myst style game. but need some help here.
like this one:
the beta cave age. light-crystals are power complicity, ether for refraction generator or puzzle circuitry. i think both.
