Forest Playable Map in VR. How do you do it?


I am trying for the first time to create a playable forest map by using the VR template and the motion controller map. It is just for demo purposes and I am using mostly assets from the marketpalce. Although that I manage to achieve a good result in other non-VR maps, things are really difficult when the HMD (HTC VIVE) is on…

The FPS count dives from 100-120 fps (play on screen) to 30-40 (play with the vive).
I have tried to optimize the performance with various settings and tweaks but the problem is still there. I know that VR demands a really low polygon count, simple materials etc but this is really difficult when the stage is full of grass, flowers, trees, rocks and animals.

Has anyone achieved a decent result (high fps>=60-90) in VR when the map is a natural enviroment e.g. a forest? How do you maintain a high performance and graphic quality in VR?

Any advice would be highly appreciated.

Seems like the forum members are not as active as in the past…

Few things to keep in mind:

  1. Outdoor areas are more expensive in general because you can see lots of stuff
  2. Because of point 1, try to use instances as much as you can, to reduce draw calls, which is the main culprit for low FPS…grass does instancing automatically, but regarding trees, if they’re placed manually, you need to replace them with instances…try to get all their position using Get Actor of All Class, save to an array, feed the array into the transform of the instance
  3. Usually trees LOD looks very bad in VR, so try to have the LOD switch where is less noticeable
  4. Check the polycount, because a forest usually has a lot of geometry, so even if 3-4 milion looks fine on desktop, in VR everything is rendered 2 times
  5. Because of point 4, try using Instance stereo rendering, not sure how many downsides there are for this.

In general, start small, empty terrain with nothing, then add things on top of it and constantly check the polycount and draw calls and see what is your PC limit, basically when your PC drops below 90.

Thanks so much for your reply. I will try some of things that you suggest.
My main problem is that the fps count is a lot less than 90 (usually 40-50) even when I started with an empty landscape by using the VR template (motion controller version). I use landscape materials that proceduraly paint the terrain and are already optimized in a very sufficient way (most of them…I think…). The trees are instanced and so are other types of folliage. The map is not that big, only 2017x2017 and I have sculpted the terrain by hand in order to sculpt only the necessary components.

My PS is a i7-3700@3.2GHz, 32 GB RAM and a RTX 2070 so I think that it is ok for VR.

Seems like natural environments are hard to run sufficiently in VR and I wonder how vast worlds like Skyrim are optimized to run smoothly in VR. I notice that most of the geometry is low poly, e.g the trees look like x-trees but I am trying to make the enviroment to look as good as possible.

Any more ideas or suggestion are more than welcome.

I just read in here ( that “If you have an outdoor scene, set your directional light to dynamic instead of stationary, and then turn on Cascaded Shadow Maps (CSM); adjusting the settings to be as simple as possible while still giving you shadows”.

Does anyone know any good settings for cascaded shadow maps in VR?

And another question…
When I use the foliage system in UE4, doesn’t that mean that the trees or grass that is spawned are automatically instanced?

I just found out that “Foliage tool uses hierarchical instanced static mesh components (HISMCs) since the regular ISMC can not do LOD per instance and you need LOD for foliage.”

Bumping the thread with knowledge! :slight_smile:

Reviving this old thread since I found an awesome example of what I am trying to achieve.

The VR game Torn is something that left me astonished with the quality of the graphics that the developers achieved in VR.

Here is a trailer of the game.

The entry scene is taking place in a dense forest exactly like the one that I am trying to create in VR.

I am really interested about the number of polygons that the trees and other foliage has. Any other info or general guidelines on how to do something like that would be highly appreciated.

Take a look at Epic Zen Garden on Marketplace.
It shows how to make foliage for mobile. Should work for VR too.

Ok I will. Thanks for your reply

Well, I checked it by opening the project and unfortunately that is not what I am looking for. The foliage in Zen Garden is not normal foliage, it’s just static meshes with a foliage material on it.

Most VR content that I found available are low poly and only in Torn I saw quality graphics used to create a natural enviroment.

Do you know any tutorials about natural enviroment creation in VR? I can’t find anything on forums or youtube.

Hi, were you able to make progress on this?