Could someone explain why this happens.
On the left is a sphere that looks fine.
On the right is the same sphere with a bump using a cloud texture.
Why is the shadow all messed up with the bumped version?
Light samples… increase them
There is only one light in the scene. A point light.
I tried changing the Sampling settings, but it didn’t help much.
I raised the “Shadow” “Sampling” to 32 and 64, and that didn’t do much.
I played around with the “Threshold” but that didn’t fix it.
I also tried “Constant QMC” and still nothing.
Any idea?
I think it is self-shadowing. Are the faces roughly where the shading is?
You could try subdividing more, or possibly applying the subsurf at a higher level?
Sorry i was confusing it with a similar texturing problem.
@organic, the does help, but it’s really impractical
I didn’t have a subsurf applied.
I took your suggestion and did apply one, and after setting it to 3, the shadows look pretty good.
It’s odd though that you don’t need a subsurf for good shadows without a bump, but by simply adding a bump texture makes the shadows expose the faces in that weird way.
Hmmmm…Is this a bug?
Thanks
No, not a bug. It is a well known problem in ray tracers. I think it is called the shadow terminator problem. I’ve been trying to find information online, but I can’t remember the appropriate keywords.
This is the best I can find for now:-
http://www.blender.org/development/release-logs/blender-234/misc-improvements/
http://www.luxrender.net/forum/viewtopic.php?f=14&t=2459
http://www.luxrender.net/forum/viewtopic.php?f=16&t=2358
http://ompf.org/forum/viewtopic.php?f=4&t=563&start=0