Skybox: issue with the luminosity of the cameras

Kappa_Delta · March 09, 2011, 10:31:09 AM

Hi everyone!

I'm working on a skybox and I have some troubles with the cameras:

http://img34.imageshack.us/i/skybox.jpg/

As you can see, there is a real difference of luminosity between my cameras.
I have 4 cameras, one for each side. Each camera is linked with a render node. The cameras are identical, only the orientation changes. The renders settingsare also the same.

I already made some skyboxes with the same method and all of them worked well except for this one...

Does somebody have an idea or experienced the same kind of problem?

Thx!

ajcgi · March 09, 2011, 11:00:39 AM

Spotted this issue on Friday. Have you tried upping the samples on your environment?

freelancah · March 09, 2011, 11:35:17 AM

The problem is due GI inconsistency. There are several things that helps. One of the easiest is to render overlapping images so that each turned render has for example 20% of the other. This way you have images where seams overlap eachother. Another thing you might want to try in addition is Ray Detail Region Padding in the advanced render tab. It basically adds an area outside your field of view to your light calculations.

Oshyan · March 09, 2011, 09:47:38 PM

Ray Detail REgion padding won't help GI issues like this, but GI Prepass Padding may. Try a value of 0.5-1.0.

- Oshyan

Floating.Point · March 09, 2011, 10:55:12 PM

I have written a tutorial covering Skyboxes.
The methods I cover eliminate issues with GI mismatch

http://forums.planetside.co.uk/index.php?topic=11608.0

Note:
To render all 6 faces with one click, you need the animation version of TG2,
But if you don't have animation, you can do it manually.

Kappa_Delta · March 10, 2011, 05:14:53 AM

Thanks a lot for your answers! I'll try all that!

freelancah · March 10, 2011, 07:53:36 AM

Oshyan can you explain why that is? Have I understood the function wrongly?

Tangled-Universe · March 10, 2011, 08:25:44 AM

Quote from: freelancah on March 10, 2011, 07:53:36 AM
Oshyan can you explain why that is? Have I understood the function wrongly?

Ray detail region padding is for calculating geometry outside of the camera's frustum/view. Shadows/reflections generated from that outside-camera geometry will be correctly rendered inside the camera frustum/view.

GI region padding works the same, but it is not for geometry but for calculating light/GI.

If you want to know more then you can search the forums for it.
A couple of others and I have explained it half a dozen times I think.

freelancah · March 10, 2011, 08:58:14 AM

Ah okay seems I had those mixed up. Thanks TU.

Oshyan · March 11, 2011, 01:14:33 AM

Yes, they're closely related in how they work, they just operate on different rendering aspects. There was a lot of assumption before the GI Prepass Padding was added that the Ray Detail Region Padding had the effect that GI Prepass Padding actually has, and I think this misconception stuck around.

- Oshyan