Foliage Instance Low FPS

Hey guys,

I’m running the new 4.7.2 engine and I’m having issue with my FPS and foliage instancing.

The grass has two different meshes, A and B. Both instanced at around 80 each. Each grass clump is about 500tri-400tri.

When running full screen, 1080p, I’m hitting as low as 11fps. I’ve set the static mesh settings to foliage instancing, but other then that, I’ve no idea how to fix this issue.

Any ideas?


Are you using the new two-sided foliage lighting model for your material? If not, I’d try that, and see if your performance increases. Also, try disabling the dynamic shadows for foliage, as depending on how many instances you have and your current PC specs, you might be generating hundreds of thousands of shadows.

In addition to that, use culling distances to fade out your foliage actors over large distances, and LOD’s for your grass material. 500 tris x 100k meshes can add up, and if you can simplify or billboard those meshes to 5-20 tris, you’ll experience much greater performance.

I’ve ran through all the grass meshes again and now at most I have 76 tris, for the biggest clump. I’ve added up all the instances on screen and it comes to: 11910. They all cast shadows, all 319 instances.

Much higher FPS, but still below 30. Any way to get that lower, or do you think it’s down to specs now?
The textures maps for the grass are 512 by the way.

This is the scene, quite simple:

I forgot to add: Yeah, I’m using the new foliage lighting model.

At this point, its likely your hardware. I’ve got a gtx 970 and I am able to have more than 500k instances before getting a significant performance drops.

I’d also try disabling dynamic shadows to see if that helps.

Yeah… I’m running a GTX 460 haha.

It’s probably the DFAO I forgot to mention. Gonna try some light map baking tests to see if I can get a nice result. Would mean I can’t really do night/day cycles though :confused:

Thanks for your time buddy! Been great help.