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[Gear VR] UE 4.12 is the worst build for mobile VR - massive performance issues out of nowhere
I hate to say it, but John Carmack was right when he recommended against using UE4 for Gear VR. While I couldn't have done what I did for my Gear VR app with Unity in the same time frame, I can never get it to perform well in all circumstances. Now I see why Gear VR apps/games are mostly done using Unity.
I narrowed down performance issue I had with 4.11.2 and it finally ran at stable fps no matter what. Now with 4.12.5 I am in the same pickle, except now there isn't any way to fix performance issues (at least I don't see how).
I don't have HISMCs or foliage in my level. The entire game logic is as simple as it can be - just doing 1 trace and revealing / hiding 1 actor base on trace hit results. Shader complexity is nowhere near to be complex (checked it with viewmode shadercomplexity when in ES2 preview), low number of drawcalls, low number of tris in the view.
When I look around and up in the sky, fps is stable. As soon as I look down to my "feet", fps drops significantly. There is absolutely no reason for it to do so!!!!
Here is a video with profiling results:
https://www.youtube.com/watch?v=uBBVrnAPuWA
I narrowed down performance issue I had with 4.11.2 and it finally ran at stable fps no matter what. Now with 4.12.5 I am in the same pickle, except now there isn't any way to fix performance issues (at least I don't see how).
I don't have HISMCs or foliage in my level. The entire game logic is as simple as it can be - just doing 1 trace and revealing / hiding 1 actor base on trace hit results. Shader complexity is nowhere near to be complex (checked it with viewmode shadercomplexity when in ES2 preview), low number of drawcalls, low number of tris in the view.
When I look around and up in the sky, fps is stable. As soon as I look down to my "feet", fps drops significantly. There is absolutely no reason for it to do so!!!!
Here is a video with profiling results:
https://www.youtube.com/watch?v=uBBVrnAPuWA
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- Oculu-bump!
- I am gonna throw away one of the blends in the diffuse part of the material and see if that frees enough instructions for normal map contraption and keeps performance intact.
- Cutting down samplers and instructions helped indeed. I guess I have to settle on less appealing visuals :(
- > performance issues when view distance from cam to terrain is short
It looks like you found it: the terrain's material is costing too much texture bandwidth. If your lighting doesn't change, you should be able to bake it along with the normal maps' contribution for a simpler shader. Looks like you may have already managed to do that?
vrdaveb said:
> performance issues when view distance from cam to terrain is short
It looks like you found it: the terrain's material is costing too much texture bandwidth. If your lighting doesn't change, you should be able to bake it along with the normal maps' contribution for a simpler shader. Looks like you may have already managed to do that?
I solved by simply getting a rid of portion where I blend terrain into sky sphere. That cut one sampler out and provided stable performance.
