Unity Grass in VR

Question

I'm working on a VR game in Unity and I just discovered that trees and grass added to a terrain bend in funky ways when you move your VR headset which is really nauseating and weird.

This is a known issue with VR and trees / grass in the terrain editor - https://forum.unity3d.com/threads/unity-tree-billboard-bug-with-oculus-unity-what-is-going-on.406006/

I opted to add trees manually as GameObjects which fixed my tree issue, but I have no idea how to add the grass since it's just a 2D image (I'm using this - https://www.assetstore.unity3d.com/en/#!/content/52977)

If anyone can point me in the right direction, I'd really appreciate it! I've been reading posts about this for an hour and feeling pretty lost!

Thanks!

Answer 1

The solution is to use 3D grass, which will be expensive in terms of system resources. There's no way around it, even if the billboard problem is fixed, using 2D grass will look strange in VR, because 2D does not have depth and you can see depth in VR. It will essentially look like how a 2D game looks in the editor when you're in 3D mode.

If you have money to risk I suggest taking a look at VolumeGrass or InfiniGRASS.

Disclaimer: I have NOT tested these and do NOT know whether they work as 3D grass or not. Use at your own risk.

If not, try making a cone shape, color it green and just scatter it around. You'll see the difference.

Answer 2

I know this is an old question but I'd thought I'd throw in my two cents.

The reason for this is because Unity terrains use billboards rotation as the same as the camera rotation. Now you don't usuallly notice this on a normal screen, but in VR it looks really strange. The billboards are simply using camera.transform.rotation and really should use something like grass.RotateTowards(camera.transform); but that would be too expensive

The solution is to not use billboard grass and simply have static grass, or as John mentioned, use grash meshes, but they might also be too expensive depending on what VR platform you're using and how many details you have