mesh light turn off spread

[Skyslicer]

does anyone know how to make it so when I create a mesh light there is no spread for arnold. I want to create a light that is just the shape of the light with a hard edge

[lee_griggs]

Do you have any images of what you mean? Maybe standard_surface.emission would work better in this case?

[madsd]

I think he wants no penumbra, but the nature is omni presence of distribution since there are no barn doors, the rays just emit in all directions.

What I do in those cases is create a physical object in the shape I want, for a square that would be a box where both bottom and top is removed and place it over the square, then hide the actual mesh from render, this will create sharp lightning.

This is also the exact procedure you would use in real life as there are no focus angles available on a normal surface emitting light, unless nested in some kind of restricted closure.

I also use this to create very sharp and long lazor beams in volumes using plane lights and very long hidden boxes.

[Skyslicer]

I am trying to get a light outline on this but the object light won't work with subsurface scattering which I am using to make the shadow puppets 

[lee_griggs]

Why does it have to be a mesh_light? Wouldn't this effect work better with a spot_light where you can use different light filters to refine the effect?

https://docs.arnoldrenderer.com/display/ARNUG/Light+Filters

https://docs.arnoldrenderer.com/display/A5AFMUG/Spot+Light