Urgent: Invisible Lights?

[CommunTwoc]

I'm working on a job at the moment modelling the exterior of two parallell buildings.
I'm using bevelled polygons at 100% luminosity that are invisble to the camera to light the interior rooms, a technique which i use often and yields excellent results.
HOWEVER, here's the pinch, although the lights are invisible to the camera, i cannot find a way to make them invisble to reflective surfaces. THUS, because the buildings run parallell to each other i can always see a reflection of one in the other and therefore one building is always full of large lumious flying white constructivist shapes. This obviously is not very realistic.
IS THERE A SOLUTION?

[kopperdrake]

Phew!

Having never used that technique I can only think of the obvious...use linear area lights instead? I'm assuming that this is going to hurt rendertimes though :/

Or you could render a version with reflections turned off to get all the opaque surfaces correctly lit, then render a reflective version with for just those that require reflectivity - though that's going to need comping together which is a pain too.

There's probably a more elegant solution but I haven't the experience with that problem to think of it :(

Dunk

[tudor]

Kinda off topic, but still:

What is your setup if you yield excellent results with luminous polygons?
Every time I try this the image turns out extremely grainy.
Do you have some special trick up your sleeve or just a lot of time to spare for huge rays per evaluation?

[Roux]

If your reflective surfaces are only windows, you could try cutting the windows into a separate layer. Exclude the layer(object) from the lights in the properties.

If you are using luminous panels, you could do multipass with ray traced reflection off and then on and comp them in photoshop. That would allow you to fade the areas with the unwanted reflections to a more natural value.

Propably not the easiest method but can't think of anything else ATM.

[etobiason]

Ummm... does making the luminous polys "Unseen by Rays" defeat the purpose (make the polys completely non-luminous)? I've never tried that... but that's how you would make something not reflect.