GI water and reflections problem

Started by RArcher, July 05, 2007, 02:28:58 pm

Previous topic - Next topic

Volker Harun

Okay, I can see why you like GI there ,-)
You could use HDR, but the poor thing with TG2TP's OpenEXR-output is that it does not really contain much data to enhance detail in the shadows as well.

bigben

Rarcher, can you try a render with the detail dropped to 0.5   I found my GI problem to be linked to the detail level.. the higher the level the worse it got

Volker Harun

Attached two images - only difference is the surface.
The first shows GI-faults in the reflections. Surface is defined by altitude
The second one does show normal reflections with changed surfaces (only slope defined)
Volker

RArcher

BigBen, Here is the render with the detail down to 0.5... as you can see the problem completely disappears.  The previous renders with the problems were done at 0.7.  You are on to something here...

Volker Harun

Interesting. The first picture I uploaded was Detail .25 - the second one with .38.
I have the files at home and will re-check it.
Volker

bigben

Quote from: Volker Harun on July 10, 2007, 04:13:20 am
Interesting. The first picture I uploaded was Detail .25 - the second one with .38.
I have the files at home and will re-check it.
Volker


I think your problem is more related to reflection issues than GI.

bigben

Quote from: RArcher on July 09, 2007, 08:56:31 pm
BigBen, Here is the render with the detail down to 0.5... as you can see the problem completely disappears.  The previous renders with the problems were done at 0.7.  You are on to something here...


I'm just about to post another test render to my series (been away on holidays). If it is related, then we have two examples of the problem at different scales. My series of images clearly shows the problem gets worse with increasing detail, spreading from the opposite side of the planet. 

Oshyan

Reducing GI to 1:1 or increasing to 8:8 seems to solve the problem. Obviously 8:8 gives more detailed lighting but at tremendous render cost. If the detail lost at 1:1 is not prohibitive then you might give that a try. Of course it may reoccur on some of the other frames.

I do think this scene is a good testbed for these odd GI accuracy and blending issues though so I'm going to pass it on to dev.

- Oshyan