PDA

View Full Version : Unseen by Camera, radiosity/shadowing.



Oedo 808
12-09-2012, 02:51 PM
Could someone please explain the relationship between self-shadowing and radiosity when using Unseen by Camera?

I guess it must be well known but I don't get why I'm getting a soft shadow at the base of an object simply because it is being hidden from the camera. With the first image (UnseenByCamera.png) if you zoom in to where the shadow begins (sorry, should have done some close ups) you'll see the shadow there is soft, the problem is this softness bleeds out in compositing. If I turn off self-shadow (NoSelfShadow.png) the shadow is hard and will not bleed out, but the light area left bleeds out at the back. Likewise with Unseen by Radiosity enabled (UnseenByRadiosity.png) the shadow is hard, though obviously with no radiosity. tt.jpg is a LW render and aa.jpg is a composite, you can see the shadow bleeding from under the box in the composited image. Now it is only a small amount but depending on what you are trying to achieve it can become quite noticeable.

I usually don't bother asking questions and treat most conundrums as an inevitable discovery, but I'm too impatient at the moment, I just don't get why this happens, I hope I'm not just being incredibly dumb, either way any enlightenment would be appreciated. Sorry these test renders are ridiculously small but I'm guessing that to someone who knows they'll be superfluous anyhow.

Thanks.

109702109701109700109703109704

Oedo 808
12-09-2012, 08:42 PM
Never mind, I don't have the issue now, I was being an idiot and using the wrong matte pass.