3D Clouds and FPS

Tuor2112

Tuor2112

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After trying all the resized textures and settings I could find I still can't select 3D clouds without dropping fps to 5-10. My laptop seems to run everything else maxed out fine so why do 3d clouds have such a performance hit ? I have updated drivers but wonder if the ATI card is a problem. Cheers

MSI GX710 (MS-171A) laptop
Turion 64 X2 TL-66
4.0GB RAM
ATI Mobility Radeon HD2600
Vista 32
FS9.1
 
3D clouds can be a frame rate killer more than anything else. I have found that 2D clouds kill frame rates even faster for some odd reason. I have my 3d Cloud detail set to max, but cloud density set to about 50%. This, on my machine at any rate, gives the best compromise between detail and frame rates.

OBIO
 
Also, you can install some low resolution alternative cloud textures (like the HiFPS textures proposed in FS Skyworld 2004 - freeware) that GREATLY improve the performance in FS9.
 
3d clouds are very "expensive" for the GPU to handle.

this is due to a technical thing called "overdraw." Because clouds are transparent, they rely on alpha maps to make them appear. However, the transparent part will require the GPU to "think" which object comes first. It needs to draw everything first, then draw the cloud, then re-draw the stuff behind the cloud...thus drawing the scene twice. Now imagine you have layered clouds...it needs to draw and re-draw the scene many times...causing heavy overdraw. Slower GPUs (and even fast ones) will all suffer a huge performance hit.

there isn't much you can do about this except to get a faster GPU. Using low-res clouds can help a bit, but not much since over-draw will still exist.

you can try a 50% 3d clouds, and also reduce layering down to only 1.

-feng
 
What I did was create a custom weather scenario and it is the default weather scheme. I created very high cirrus clouds and that reduces the impact on frames, and still gives my sky depth.
 
Yes I have set up several weather situations but it makes using any kind of real weather impossible unless its a clear day of course.
 
Have you tried the alternative cloud textures I have mentionned ?
On one of my old computers (Pentium IV 1,7 GHz with a GeForce Ti4400... wow that was a long time ago...) I was forced to use those textures, else the performance would just free fall down to 5-6 FPS on any rainy day...
 
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