Occasional Render Issue

[RichTwo]

This happens occasionally, and seems to rear its ugly head unexpectedly and repeatedly when I am on certain projects.  The render will start, completing the pre-pass smoothly, then at 50% or 66% through the final pass it freezes for about 15 minutes then resumes and completes without a hitch.  All the while during the interruption, the render clock is ticking away while no progress shows on screen.  So in the background something is going on, but what?

I know that there are certain factors such as path tracing, reflections, water, or displacements can slow down a render and I always take those under consideration.  What seems to be associated with the freeze is the convergence between sky and terrain, though I don't know why it would.

I am using a renderer with customized sampling settings, one that Oshyan set up for me when I was experiencing a very slow render time on a certain project.  When I switch to the legacy sampler, the same thing happens so it's not the settings.

Has anyone else experienced this?

[WAS]

This could be related to your POV. If you can see the terrain cascading off the horizon of the sphere, plus v2 clouds or v3 clouds off in the distance, and again like you said any calculation factors therein.

What you could try is culling any reflections and such with a distance shader.

Though the heavy pause does seem like something else. You could be peaking RAM and system creating cache files in virtual memory on C drive which will already be under load with the OS and other apps

[RichTwo]

Thanks, Jordan. I believe that I have found the cause. When I render a scene with certain .tgc's the freeze occurs. With them removed all is right with the world. I'll just have to make the sacrifice if I want to use them.

[WAS]

Yeah, some TGCs are heavy, or have scales relating to specific scenes that can throw things off big time. A lot of my old shaders are very high fidely because of freeware quality limitations.