For the native Rhino area lights is it possible to add a feature to control the angle of emission of each point in the area light. It will behave like a spotlight, but with a wide emissive area
Cycles does not have angle control for area lights, so it is unlikely to happen any time soon if at all.
If you need to restrict the area light can reach you probably are best off placing an area light in a recess.
Consider using Rhino’s “Hole Wizard” in SolidTools to create the recesses. Using that method makes it very easy to duplicate (copy, array) the recesses and/or delete them later. Only limitation (to my knowledge) is that a “hole” CAN’T be placed directly at the edge of a polysurface which would be nice, since you could then also use the feature for doorways.
This is called “Directionality” in V-Ray. It is much needed in Rhino’s native renderengine (cycles).
Maybe in the near future I could add a special light material based on this
Logged as RH-64696 Directional area light.