http://www.blendswap.com/blends/view/80449#comment-79003
Or check out this gameplay 
It’s really great looking, but it runs really slow on my computer (which has a fairly good GPU).
You should make sure your textures are power of 2 sized, ie: 256x256 or at most 1024x1024. Those huge giga sized textures are really slowing it down. The rain texture was 1920x1080, that’s as big as my screen resolution.
I shrank them down to 512x512 with no reduction in quality.
The rain is also not very efficient, instead of using alpha blend with a .png texture, try using just a black and white texture, with very dark whites, and set it to “add” type transparency. That doesn’t need any transparency settings other than that. Additive blending will actually give a better result in this case.
You can also use billboard setting and backface culling for much better performance (instead of having a track to actuator on every rain object).
It would also be a good idea to use less lights…
If you make these changes you’ll see huge speed improvements, I go it up to 60 frames per second on my PC (from 17 frames per second when i downloaded it at first) with no visible reduction of quality.
BTW: I loved the mist, that was a really good idea. It works kind of like an AO filter, but really cheap and efficient.
Also bake normalmaps or generate them in GIMP instead of using the diffuse color as normalmap!
Cool scene, cool demo! Though you might want to make the raindrops look less thick than they’re now. I would believe it were snowflakes…
link error… link please
