start by adding a new spotlight, rather than changing the default lamp into a spotlight, which creates problems in my experience. check the docs for specifics.
you make the object translucent by adjusting the translucency slider.
not sure what you are asking.
for the material that receives the shadow, set to ‘trashad’ ( transparent shadow )
I want the spotlight to hit the cube and illuminate the whole thing, kind of like a laser pointer in a pane of glass how it’ll disperse but still pass through.
I want the halo to filter through the cube and go from white to purple, and project purple onto the green plane beyond it.
If possible, I want the light to pick up the nor texture on the texture and project that as well.
Actually, it isn’t. If you look closely at your image, the green surface is just visible in the spot. Purple tinted light on a green surface isn’t going to show up well anyway, and the intensity of the light is fairly low by the time it gets there, so the result is at the threshold of detection. Increase the energy of the lamp, or make the colours less nearly complementary, and the spot on the surface will be obvious.
I want the spotlight to hit the cube and illuminate the whole thing, kind of like a laser pointer in a pane of glass how it’ll disperse but still pass through.
Turn down the gloss on the Ray transparency (possibly with some Fresnel as well) and add a dose of Translucency to the shader. But this probably won’t give you enough illumination, and you may need to fake it with some Emit as well.
I want the halo to filter through the cube and go from white to purple, and project purple onto the green plane beyond it.
Unfortunately, AFAIK halos are only affected by intervening objects if you use buffer shadows, not ray shadows.
If possible, I want the light to pick up the nor texture on the texture and project that as well.
Alpha or Colour textures do project, but you’d need something like Global Illumination before Normal textures (or even Displacements) could do so. Refraction currently only affects the path of rays from the illuminated surface to the camera, not those from the lamp to the surface; if it did, we’d automatically have support for caustics. This is also why you will probably need some faking for the dispersed illumination in the block.
You can get part of the effect you want by adding a point lamp inside your block, making it light only objects on the same layer, and putting it and the block on its own layer.
Also, don’t overlook the possibilities of compositing nodes. Sometimes the best (and cheapest) way to achieve a lighting-effect is to construct it by combining simpler things. That is to say, deal with each part separately.
Basically, what I did was ended up changing the spotlight’s projection distance, adding an area light inside the cube, and adding a second spotlight with the color of halo I wanted. I’m having trouble getting this to look right, though…
When I switched the spotlight to ‘buffered shadow’ it did not filter the halo through the object, even when I set the object to ztransparency.
