Author Topic: Stretching texture under tessellation?  (Read 958 times)

Would anyone happen to know what could be done about the stretching going on under these blades of grass?

That’s a fundamental limitation of displacement maps, unfortunately.  The rapid falloff in height at the hard edges on each grass blade is covered by only one or two polygons, so the ‘stretched’ look is always going to be an issue.

There are a couple of things that might help, but none will be a perfect solution:

- Make the height falloff at the blade edges not as sharp, by rounding, blurring or bevelling.  Not as crisp-looking or realistic, but will avoid as much ugly polygon shearing.

- Reduce the overall height of your displacement.  Not ideal, but displaced grass won’t work super close-up anyway, so you might get away with it, and this would reduce the problem, too.  Obvious, but worth considering!

- Try to create your grass blades using vector displacement.  Not at all easy to author in substance designer, but it’s been done.  This will allow actual overhangs, but is often really tricky to set up in the target renderer as well.

- Add an opacity map, and create your grass in a couple of layers.  Obviously heavier, but most of your existing work would be directly re-usable.

- Abandon tesselation entirely, and create a tiling mesh from overlapping strip curves.  Throws away a lot of your work, which would be frustrating, but should enable you to maintain the same look.  Might actually be lighter, too.

- Abandon tiling, and go with a mesh scatter solution.  Throws away basically all your existing work, but I figured it was worth adding for completeness.

Thank you Alex! I will give these a try! This is gonna be awesome