I have a scene with a cube inside an icosphere. the cube in the middle is my viewpoint object and i want to render a cube environment map. my environment is the textured inside of the icosphere and some other objects inside the icosphere. now my question is how can i achieve getting a blur effect on any of my objects inside the icosphere? if i put the objects i want blurred in another render layer and set up notes (blur) for it, it doesnt render the effects when i create the environment map. is there any solution for me?
If your environment texture on the icosphere is unblurred:
Render everything into 1 equirectangular environment map. Blur it in your favourite 2d app (it is seamless so tile it before blurring) or inside cycles nodes with noising the mapping inputs with b-wide node pack.
Then render this blurred environment into the cube map.
If your environment texture on the icosphere is already blurred:
Render the objects inside the icosphere only. Lit them with the environment texture but exclude the icosphere to not reflect on the cube.
Blur this equirectangular inside 2d app to match blur of the enviro and merge them into 1 environment (you will need an alpha channel for this also).
Then render a cube map from this blurred enviro.
You can use material indexes: select all materials - one by one - wich you want to blur and assign them a "1" index, all the rest can remain with the default "0" index. If a material is shared between obiects, create a copy. You can reach material index in the material proprieties: Blender Internal - option - pass index; Cycles - settings - pass index.
In your single render layer check the "material index" button under "pass" tab.
Then you can use this simple node setup in the compositor:
Working with object indexes is quite similar, of course.