I recently ran into an odd problem.
To show you what has been going on, I created this bare bones version, pared down to its basics. As you can see from the attached screenshot, the problem is having part of the image missing during rendering. I say part, since not everything is affected. In this example, the entirety of the bulging, round feature sitting on the spire appears in the preview window but is truncated in the rendering.
I have attached the tgd file in case this might be of some help.
With extreme displacements you might have to increase displacement tolerance in the planet node. Try a little higher at the time (1.1... 1.2...etc), as it increases render time.
What comes to my mind is low RAM issue, but that would be strange on a relatively blank image...
Did you get any error messages? TG sometimes tends to omit render buckets that it finds too memory-consuming to process, leaving out black squares in an image. This is especially true on older systems. Are there any reflective / glass surfaces on this spherical rock?
Afaik it's displacement tolerance.
Thanks for the advice, everyone! I'll see what happens!
Adjusting the displacement tolerance did the trick!
Thanks!
I'll go back now to the original project and apply the fix there.