Optimizing for VR performance

    Hi,

    I'm creating this outdoor landscape in Sketchup for VR, by adding trees from the Asset Library.

    But, I realize the Assets don't have different Level of Details (LoD) in it. So the trees in the background will have the same amount of polygon as the ones at the front. Is there any plans on Implementing Automatic LODs like in Unreal Engine? The closer you are to the asset the higher the polygon count, since putting a lot of trees in a scene will decrease performance by a Lot.. Currently I have hundreds of trees and shrubs on my model and I have around 40-ish frames per second in Medium Quality on VR. I'm aiming to get around 70-90-ish frames.


    I think Asset LOD's a must have for VR, especially on outdoor scenes


    pierrenp , thanks a lot for your post.


    Two questions right away:

    - What GPU are you using in combination with Enscape VR?

    - What VR headset are you using?


    Furthermore, we actually do make use of LODs, it's just that the transitions are designed to be as subtle as possible, which is why it can be hard to even see the differences, but it's there, up to a 35% reduction in complexity each which of course saves a lot of performance, and would vice versa otherwise make the scene probably unnavigable with so many models placed.


    Of course, having a LOD system that isn't noticeable is usually the goal - When it comes to your performance problems though, we can only recommend either upgrading your GPU, or for less drastic measures, reducing the scene in complexity (removing some trees which aren't in direct sight or not really required), and/or setting up scenes with certain elements hidden (perhaps specifically for VR navigation), and/or using a section cut.


    Alongside you could also look for low-quality/low-poly tree models online which you could import as a proxy or custom asset. These could be placed further in the distance where it won't be noticeable that they're of low quality. Plus a dedicated custom skybox/background with trees in addition or instead of some may also help with selling the impression of a small forest without taxing the machine too much.


    Last but not least, you may perhaps turn down the rendering resolution of your VR headset a bit further, which in combination with less complexity in the scene should allow you to hit at least 60 FPS after all.

    Hi,


    Thanks for your reply, to answer your questions, here are the answer:

    1. I'm using an RTX 3080;

    2. I'm using an HP Reverb G2 and also tests using an Oculus Quest 2.


    I see, so there was already LOD system implemented to have a 35% reduction in complexity? Any future plans on making the LODs have further reduction, like 50%, 85%, until turning the trees to billboards? This might be so much helpful for creating complex landscapes.


    I did remove a lot of trees actually, but since this project is like an urban forest, people maybe wanting to roam every area of the park, in that sense most trees in the approachable area has to appear realistic. The scale is not as big as the NY Central Park, but it's quite dense.. Having significant complexity reduction will help a lot. I tried replacing distant trees using assets generated on Speedtree, but it didn't help that much..


    DLSS helps, but it makes the screen flicker..


    I hope you guys might consider having more LOD complexity reduction like the ones shown in this image.. Thanks