So, weird stuff happens with Intersect Underlying...

Started by WAS, July 27, 2020, 12:33:56 pm

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I've always had trouble with this feature, getting scales right, effect right, effect to hold over when a new surface layer is added between, etc, etc,

this, well, this is a new one: If the surface layer has smoothing activated, strange things happen. The surface layer has micro displacement for sand, and sand waves, at a tiny scale, that's it. So I assume this is because the layer smooths the terrain for the sand. Just thought I'd show off this quirk and make it known. Lol


I think it looks like it should, but don't know your setup, and what you want it to look like. It should smooth the smaller details out, depending on the compute terrain patch size. If you make that tiny, there's hardly any smoothing, really huge and whole mountains may be smoothed away.
If you need to keep sand textures, better apply them after the intersection.


It seems to extrude the terrain upwards (similar to Vertical Only), along with the texture weirdly. Usually when I add smoothing to finer detail (we're looking at 0.2-1m PFs and some rocks everything but the rocks down to the compute terrain seems to simply vanish, I never noticed any offset


I can see that something is wrong in these examples - there is some strange shading visible in both images. Can you post a .tgc of the nodes involved?
"This year - a factory of semiconductors. Next year - a factory of whole conductors!"


I don't know if this helps but changing the value of the patch size in the Compute terrain node has quite a dramatic effect on the spread of intersect underlying.

You can also add a second Compute terrain node (at a render speed cost of course).

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I have patch size at 5, which probably explains the extrusion along the detail maybe actually. With a patch size of 20 this probably isn't so noticeable on roughage. 

Also never even thought of chaining different patch sizes for shader effects. Brilliant, thanks for that.


Also, you don't need complete smoothing, but can build it up in a line of surface shaders, using intersect in different stages. Like for meltwater off snow, or so.