Geometry Nodes - Grass...

I had a fairly simple idea that I wanted to execute as part of my landscape: wavy, windswept grass that could be displaced by a landing spaceship. Having had very little experience with Geometry Nodes, I was hoping that I could rely mostly on the use of particles and physics simulations. However, in order to create a dense field of grass (at an appropriate scale) I soon realized that my computer would not be able to handle the necessary number of particles (ran out of vram when rendering). So, I had to see if it was possible to do what I wanted to do with nodes. It was a long road.

First off, I learned early on that I would be unable to create a wind effect using actual wind. So, I created some sine waves that ripple across the surface of the curves. Then, I had to change the rotation to match the breeze to give it a sense of scale; tall grass sways differently than short grass. All of that was fairly easy. The hard part was getting it to interact with an object. With instanced meshes or points, I may have been able to save myself some trouble. However, curves are annoyingly stubborn. After hours and hours and hours... In the collection of Hair Curve nodes, there is a shrinkwrap function. It turns out that you can use it (in reverse) on an object that is ABOVE the curves to create a somewhat decent displacement effect.

I think I need to increase the size of the sine waves but this whole thing turned out almost as good as I was hoping for.

Now I just need to try and create a larger environment. Instancing a plane of grass to create a large field will be my next adventure into Geometry Nodes. I have a feeling that my computer will not be happy about it.