I have strange artifacts on render of specific frames, and I can not track what is problem. It is not sampling problem, nor double polygons …

And this affects several frames through out entire animation.

Entire animation can be seen here.
http://vimeo.com/36339204 [vimeo.com]
PBR used.

Any suggestions?

Shadow maps could be worth a check.

rob

Tnx for reply.

I think that is somehow related to geometry, even I disable lights I see artifacts, not so strong though. Also I was using raytraced shadows.

One more problem I have with this scene. I can not open it if I have cooking set to auto, upon starting I got memory fault and Houdini crash. Scene however takes 2GB of 12GB I have. If I set cooking to manual, open scene and than set to auto it works ???

As things are now, I will need to choose another, lighter scene to practice more of Houdini ….

Can you upload the file?

Sure, here you go. No tree models and textures uploaded.

In archive is hipnc file and obj file of terrain.

It might be a raytracing bias problem, since your geometry is quite large.
Try increasing it in the shading tab of your rop to 0.1 (seems to work for me)

Yeah, that did it!

Thank you a lot.

About problem with Seg faults and crashes, when I deleted all IMG ops it stopped crashing. I used some to gamma correct textures, and link to them with op/.
How do you guys gamma correct textures in Houdini?

http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&p=92329&highlight=&sid=8ce0dd718e12ad786af4ba7e2f7f2edd [sidefx.com]

This explains how to gamma correct the texture inside of the shader.