texture with transparency and performance

I asked a question about how to make effective grass before: [[SOLVED] grass and lightning...)

In that thread I mentioned that I use the technique described here: http.developer.nvidia.com/GPUGem … _ch07.html

So there is another problem now. The framerate on some hardwares seems to drop catastrophically even with so little grass: mediafire.com/?qnji2mywy1m

I get around 30 fps with that simple sample on some modern hardwares. Is there an explanation for this? I probably tried all the alpha modes.

Can you guys try the sample and tell me how much you get?

250 FPS (nVidia 8600 GT).

I get 210-230fps on geforce 9400gt.

130-140 on OpenGl and 200 - 250 on DirectX(GeForce Go 7400).

60 with NVIDIA GT 120 and … wait for it…
53 FPS on a Mobile Intel 945 Express Chipset Family :slight_smile:

OGL : 390
DX9 : 500

What do you most often use DirectX or OpenGL?
(I have one project on DirectX with 1200 FPS :laughing: )

@tallmystcarpet: 60 fps sounds much like your frame-rate is capped at this.

Indeed, I’ve red something about adding a line in config.prc to uncapped it…
As I already faced Anon’s problem with transparency, I remember that the frame rate decrease a lot 20 ≈ 30.
Using MDual transparency mode solved my problem but he already try them all.

the line to put in is:
sync-video #f

Hmm, any suggestions on how to imrpove the performance? The amount of grass is very low compared to the demo and it doesnt have a vertex shader.

What system setting and hardware are you using?

I dont think thats important. Grassblades take up too much resources in any PC I tried.Even if this demo runs in realtime the actual game will slow down when the camera renders the grassblades and will return to normal when you dont look at them.
the hardware on which I got 30 fps was a intel core i5 m430 2.27 ghz 4gb ram and geforce gt320m gfx card. Strangely, I downloaded the newest Panda snapshot build and now its 200 fps… Maybe something important was fixed? Or I forgot to change something in the prc file.
EDIT: Right, with any multisample enabled, the framerate will drop to 30 on this hardware.

My actual game, where other stuff are happening, still slows down when you look at the grass. So I thought there should be a way to improve the performance. Right now I’m using two sided faces, not doubled. The trasnparency mode is binary alpha. I thought experienced people could suggest me a way to improve my performance. the GPU Gems page doesnt mention anything about this.