QuoteWhen the plane is rendered, its surface position determines the texture coordinates for the shaders it's sampling. Power Fractals are 3D textures, so changing the Y position of the plane will change the texture which is generating the terrain. So the plane needs to perfectly match with the undisplaced planet. For complete accuracy you should just render a planet, not a plane, because of the curvature.
I couldn't make projecting the displacement onto a planet work, so I used the Lake object instead as that follows the curvature of the planet - works just as well. Haven't tested it on a very large terrain, but I imagine that's where you might see some misalignment.
I've attached a new TGD file for this, and added a render layer for the Beauty render which hides the water object.
QuotePersonally i would increase the Detail to about 0.8 (or maybe even 1.0) to get the micropolygons to be about the size of a pixel. Otherwise you're not really getting the full benefit of that 4k resolution and potentially producing artefacts as values jump from one micropolygon to the next (because each micropolygon is solid shaded). Anti-aliasing of 3 should be good enough.
Tried it at Detail = 1 and it's better, at a minimal increase in render time.
Dune - no, you don't need a Compute Terrain node. In fact, as mentioned, the Displacement to vector should be taken before that node. The test scene I used is very simple and there's no shading going on that needs the Compute Terrain piped into it, I just didn't delete it.
The next thing to test is add small scale displacement further down the tree into the shading group. My approach has usually been to do large scale displacements / terrain sculpting then a Compute terrain - then adding small scale displacements along with shading after that. It will be interetsting to see how that could work and preseve that extra detail. You say you don't use the Compute Terrain node sometimes, are there certain situations where you don't need it?