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Grass Foliage Lag

Hey everyone. So recently I started using Unreal’s Free Open World assets for my game. I just started playing around with the foliage tool by placing grass in my world. However, I really want pretty dense foliage and am experiencing heavy lag because of it. What are the best practices to still have dense grass foliage but not have huge frame drops?

Kite Demo’s assets are not optimized enough for an open world game.
Also UE4 doesn’t handle dense foliage very well compared to other engines.

Set the end cull distance to a reasonable distance, like 10,000-20,000 units, and don’t use more than 4-10 polygons per mesh.

I see. What type of grass assets do you guys recommend to have optimized foliage?

Overdraw is the most important thing here. Your grass should have the minimum overdraw possible since even then you’ll still have a lot of whites in shader complexity when using grass tool.

That is true. If you can save more instructions at the cost of a couple extra polygons, do it.

Could you tell me what is overdraw here? Is it something to avoid or to apply? Thank you.

It’s the transparent areas of the grass mesh. When you apply an alpha map to your grass model it only shows the grass blades and the rest of the model has 0 opacity. This 0 opacity part is toxic for performance so you have to model your grass meshes with a few more polygons and minimize these transparent areas as much as possible. (Also avoid spending so much polygons too).

Thank you very much. Your explanation really help me understanding better.