Burst Render Gives Twice The FPS as Instancing...

[Leto]

Humus, I have a question for you or anyone that would know the answer.

Is it possible to render the grass in a game like Madden or Fifa with as pretty grass as we see in Farcry or BF: Vietnam using instancing seing it's pretty big scale compared to the small patches we see in Farcry and BFV?

Is rendering 100k grass leafs 10 times as demanding as rendering 10k grass leafs.

It's about time we get some real grass in Madden/Fifa!!!

I haven't played those games so I don't know how things look now, but rendering grass is one of the things where instancing may provide a benefit. If 100k grass leaves end up as 10 times as demanding depends on what's the bottleneck, but it will likely a good deal more demanding though.

Future demo from you maybe?

 

[Humus]

Why would you use instancing for rendering individual grass blades? Seems completely moronic to me, you can just aggregate blades into patches or clumps of grass to reduce call overhead, which you're required to do anyway for any sort of LOD system (which is pretty much required for grass, e.g. full geometry up close, fur/3d textured shells further away and flat geometry with fins even further away). Changing the modelview matrix for EVERY blade of grass doesn't seem very efficient to me, even with instancing. It's not like storing vertices for a couple of hundred blades of grass consumes vast resources anyway.

Nobody said you have to do it with individual grass blades. Instancing applies equally well to patches of grass. You will have many patches to render, so batch all with the same LOD into the same draw call with instancing. Nothing says you have to provide a full modelview matrix for each blade either, or even for each patch. There are no restrictions on what kind of data you can pass per instance. For grass you probably don't care much about rotations, so a position is probably enough.

 

[Humus]

Future demo from you maybe?

Nah, I have more interesting ideas to work on.