Sorry if this has been covered, but my search results have been muddled with a lot of talk about baking/capturing cubemaps and skyboxes.
What I’m trying to do is project a cubemap from a point light to give my interior lighting a lot more atmosphere and character, but I can’t figure it out at all.
Is this possible, or do I need to set up 6 (square) spot lights and project each texture separately?
Thanks, but the concept has been misunderstood yet again…
I’m not trying to capture/bake a skybox, I’m trying to project a cubemap from a light, preferably attach all 6 images to 1 point light. Otherwise I would have said I could set up 6 ‘cameras’ instead of 6 ‘lights’, which is the only way I can manage to do it at the moment. The main reason I don’t want to do it that way is because A) it will use a lot more objects in the scene, B) because I would like to rotate them all on funny angles and I worry 6 separate lights will be tricky to manipulate and adjust all settings as 1 entity, and C) because one day we’d like to get this light information out of Blender via a Python script that can dump basic info to a text file, to put them into a real-time 3D engine. I’d rather not need to deal with cleaning up 5 spot lights out of where it should only be 1 point light.
Ideally just 1 point light projecting in all directions would be easier and more manageable.
It seems nobody knows, maybe nobody has tried this before?
One solution I have is to encase the light in a very small cube and render it with shadows casting from that translucent material on the cube. This works good, but I have some trouble figuring out how to make the cube visible/working for only that light and so other lights won’t try to cast the cube’s shadow. Still trying to figure that out. I tried playing with “light groups” but I can’t understand it thoroughly just yet, maybe it’s not what I’m looking for. I guess I need something like 3DSMAX’s include/exclude system?
The other solution is to try to convert all of my cubemaps into single-image spheremaps and set the “projection” to “sphere”, but this doesn’t seem like it will work because when I assign a texture to the point light, unless I’m missing something, this option is not available. I can only choose between “object/view/global” with no projection options. Maybe one of these options will assumedly treat the texture like a spheremap anyway, but I’ll need to do a lot of testing.
So it seems the first solution is probably the best? I’d really appreciate any advice about this, even stabs in the dark…
" I worry 6 separate lights will be tricky to manipulate and adjust all settings as 1 entity" - if you add into this half a bunch one Empty and parent/constraint cameras, spotlights or whatever to this you can manipulate just one object. Drivers could help to deal with separate parameters.
Martinsh did not mention a word about capturing the cubemaps, his article was about cubemaps used for reflections in interiors, conversions needed to get them working properly. I assume if reflections look right, lights coming from such map should look right too. I still somehow doubt because World light is not/should not be treated as a directional; what you try looks exactly opposite to me.
For BI there is option This Layer Only for lamps; you can have object on two layers at once (select object, press M key and Shift click another layer) while different lamps (and enclosing objects) are on separate layers (http://www.pasteall.org/blend/39858). I do not think Cycles has this option.
GL.
Thanks for your advice. I’ve been spending some time reading about layers but I still can’t seem to get it…
I’ve provided a shot and the .blend to make it easier and hopefully I can wrap my mind around the combination.
The cube in the middle of the room casting the shadow should not be ‘visible’ to the green light. You can see its shadow in the middle of the green spot light, but it should not be there. I set that cube to only the 3rd layer, the white light in the middle to 1st and 3rd, and everything else only on the 1st. The green light is only on the 1st layer and the cube is only on the 3rd layer, so they shouldn’t interact with each other? That seems logical in my mind, but obviously not to Blender:-
Checkbox This Layer Only for the green Spotlight? Does this make a difference?
Ah yes, that fixed it! I was toggling this option on the wrong light… Thank you Eppo! 
I’m also trying to figure out if 20 layers would be enough for an entire level. 20 different cubemaps is probably enough, but not 20 shadow-casting objects. I will need to experiment and see if I need 20 different layers for everything, or only in certain areas of the map, etc.
