I am looking for a way to impose a spherical reflection map (only reflection) on an object. Only that object. Actually, even sub-object restrained by a mask. I want the spherical map (an HDRI) to only contribute to reflection, I don't want it to light the scene.
A bit link a chrome material, except the entire reflection would be artificially imposed by me via and image.
In scanline, I would just plug a bitmap in the reflection slot, set it's coordinates to 'spherical environment', and that's it.