Black Area Lights

[user_deleted]

Any time I render an area light with the "visible" option turned on, it renders out black, as opposed to the expected white... anyone know why? I imagine there is a simple solution to this that I am just missing, but I was wondering if this has happened to anyone else and if anyone knows how to fix it. Thanks.

[user_deleted]

Upon examining the alpha channel of the image (which I should have done in the first place), I see that the area light is, in fact, not black, but simply not present. The space in which the light should be has a completely transparent (black) spot in the alpha channel. The light itself works fine, but simply creates a black spot in the alpha channel, displaying whatever background color I have set for the camera behind it in the color image. Again, this only happens when I set the area light to quote-unquote "visible." So, as a correction to my original question, how do I prevent the area light from having this "black hole" effect in my image?

[user_deleted]

Hopefully the last addendum... Still rendering out as a "black hole," but, contrary to my above statement (which, I confess, was stated in theory), it renders out black in the color image, regardless of what my camera's environment color is. Anyway, the basic problem is the same: Area lights set to "visible" render out as black holes. Any help would be greatly appreciated.

[jozvex]

Ok I have some ideas,

What shape light are you using? The Rectangle and Disc shaped lights are only visible from the side in which they are pointing (shown by the normal line), because they are one sided.

And are you using a point light? Because I just tested it with a point light and all the different shapes rendered fine.

[user_deleted]

I am using a spot light, rectangular shape, and, yes, I am looking at it from the direction it is pointing... but, when I use a sphere shape, it does the same thing. I haven't tried it with a point light, I suppose I will try that. Give it a shot with a spot light, see if you get the same results.

[user_deleted]

Well, a point-turned-area light gave the same "black hole" effect... so I don't get it. Especially if others have it working. The lighting works perfectly, I rendered out a very nice cornell box (used a single-poly plane with a 100% luminant white shader applied to "simulate" the visible area light), so everything else works... Just can't have a visible area light. Oh well, no big deal, really. I can continue to use planes or spheres or what-have-you as stand-ins for the visible area lights. I am still very curious to know whats going wrong, but its not top priority. Thanks.

[ben_k]

Perhaps it is an issue of scaling the lightsource and intesity:
I encountered the Problem with lights with a linear+ dropoff, while otherwise the light shows correctly.

I duplicated my lights, turned visibility off with the originals and on with the duplictes, and made sure the new lights did not emit lights or photons.