Better Performance when setting shadows to high

[mr.g-c 6]

Hi, i just had a short session trying to further improve the performance of me and my brothers Arma installation (actually playing 1.12b), and through a coincidence i found out that when having shadows set to "high", rather than to "low" i got around ~3FPS more and my brother on high machine got even ~5 FPS more.

Isn't that strange?

Its a great deal because you have better Optics (shadows drawed on houses for instance) and more FPS...

Just wanted to share this with you, since 3FPS more is much in Arma, especially when you are under 30FPS in certain locations.

Best Regards, Christian

[maddogx 13]

This is already known, but it doesn't apply to everyone.

The high and very high settings use a different draw method than medium and low. On some computers that method is more performant than the "lower" method, for some reason. You are one of the lucky ones.

[-DirTyDeeDs--Ziggy- 0]

could you please post your computer specs, game settings and scene in which you benchmarked your fps.

thanks

I'll see if the same goes for my game.

[maruk 80]

Shadow detail high is more demanding ont he GPU power than shadow detail Normal or Low but it is also less demanding on the CPU so that may explain it for some configurations.

Using shadow detail high is probably best choice for any powerful modern GPU.

Shadow detail very high requires more VRAM than high otherwise there's no difference.

[lee_h._oswald 0]

Hi Maruk.

I'm using a GF8800GTX 768MB and shadows on Very High.

Can you please tell me, why some shadows(like in the picture or tree shadows) on normal(Cpu rendered?) look crisp and blocky on very high(Gpu rendered?)?

Thanks.

MfG Lee

[mr.g-c 6]

Quote[/b] ]Shadow detail high is more demanding ont he GPU power than shadow detail Normal or Low but it is also less demanding on the CPU so that may explain it for some configurations.

Using shadow detail high is probably best choice for any powerful modern GPU.

Ahh that explains it....

Thanks for that........ my GPU is a GF9600GT, but my Processor and the rest of the system is pretty old....

Best Regards, Christian

[kegetys 2]

why some shadows(like in the picture or tree shadows) on normal(Cpu rendered?) look crisp and blocky on very high(Gpu rendered?)?

I believe 'normal' uses stencil shadows (sharp edges) everywhere, while with high you get either shadow map shadows (smoother looking edges) or stencil shadows depending on how the model is configured. With high the shadows are also cast on smoke etc. particles.

[volkov956 0]

u may also notice the same Blocky shadows on a plane kinda being jittery as well when on High

[lee_h._oswald 0]

Thank you Kegetys.

What do you think, is there any way I(we) can use high/very high shadows without the "blocky mode"? (addon, config, model change?!

Edit: @volkov956

Yes, I noticed them, they look terrible.

Edit2:

Just had a look at the aircraft shadows and found the next strange behavior:

MfG Lee

[TankCommander 3]

Those blocky shadows on the aircraft looking so bad could be fixed if the programmers simply made it so when vehicles self shadow, it is crisp as opposed to blurry. Only larger objects like trees and building look okay with blurry shadows as it is more realistic for an object casting a shadow further from the ground to have a less defined shadow. So when the A-10 casts a shadow on itself, the shadow doesn't travel far so it should be crisp.

It's an idea at least if they want to fix it up a bit and create a better mix of shadow effects.

[-DirTyDeeDs--Ziggy- 0]

... You are one of the lucky ones.

hehehe

I gained framerate changing from low to high shadows

[OrLoK 20]

Hello all

I have no idea how the arma engine works but the Jagged shadows look like its using something called a shadow map.

If you increase the shadow map size you get crisper shadows, but it takes more resources.

It's common in 3d rendering apps, but whether its the same thing and can be altered in any config is a diff matter.

I could be completely wrong but thats how I've always thought of them.

rgds

Lok

[mr.g-c 6]

Don't ask me why, but somehow i like the crispy shadows you get when you turn shadows to "high"

Ok they could be a little bit less crispy......

Regards, Christian

[TankCommander 3]

Yeah blurry shadows are made via shadow maps and the 'raytracing' effect is done with shadow objects. Not too sure how the objects cast shadows as they are, maybe someone else can explain it?

[OrLoK 20]

oh and another thing,

In most apps I have used (Max, XSI etc) shadow maps (the blurry ones) usually take less processing power than the "crispy" "raytracing" ones. I dont know if this is true in arma.

I'm not at me gaming PC so i cant see Armas settings.

Is it crispy at high and above? or blurry? looking at the above posts im confused.

I would assume blurry then crispy in the level settings.

(depending on some caveats I know, but as a rule of thumb this is just about true before i get flamed)

Rgds

LoK

[chALLn(ger) 0]

Not too sure how the objects cast shadows as they are, maybe someone else can explain it?

Here are some in-depth articles about the two shadow-casting techniques:

Shadow Mapping

Shadow Volume

The first one is texture-based and causes those jagged edges, if the texture resolution is low. This can be avoided to some extend by applying a blur effect, such as a gaussian filter.

Performance mainly depends on the resolution of the shadow-texture.

The second method relies on finding silhouettes and projecting them onto world-geometry to create shaded areas. Unfortunately it is kind of hard to get blurry shadows with this approach. Performance mainly depends on the geometric complexity of the objects casting shadows.