Scrolling displaced tessellation

Development Rendering
1

Hello,

I’m trying to acheive scrolling lava with some kind of displacement. I have my tessellated mesh looking good… until the displacement scrolls across it - then I get nasty looking jumping as the verts are jostled up and down by the displacement. A higher resolution tesellation could help, but the video shows it at a value of 1.0, and when I try starting from a higher density mesh, the tessellation behaves very differently. (see image later below)

I can’t seem to use bumpoffset because the UV inputs on the maps are being fed by Panner nodes. However, I consider that a backup and assume in-engine tessellation is technically the correct solution for this anyway. But please correct me if I am wrong and/or if there is in fact a way to get the bumpoffset to work, though - see the graph below.
video of the problem:

the high-density mesh with tessellation shader:

793×816 716 KB

and the graph (sorry it’s blurry):
1537×1031 320 KB

Tessellation settings: Flat, crackfree (no), adaptive (yes), max disp (1.0)

Any ideas on how to make this work? It sort of looks cool, like bubbling, from a distance… but is a mess up close. It may be obvious what I am doing wrong - i’m still pretty new to this stuff. :slight_smile:

Thanks a lot in advance!
d

2

Have you checked the lava example in the Elemental scene? It should provide you with everything you need.
Also, incase you end up with weird results when using animated displacement, the first thing to probably check is your mesh’ bounding box.
Sometimes increasing its scale can help.

3

Thanks for the leads, Chesire. Turns out max tessellation is relative to size (i was scaling up), so that fixed it. And I had somehow missed the Elemental scene, which is a great reference. Thanks again!