Stencil shadows vs Shadow Maps

[DaRkL3AD3R 1]

Update: Ticket added! http://feedback.arma3.com/view.php?id=8233

Please go to the tracker and upvote this to help minimize CPU bottlenecking in Arma 3!

Shadows settings on Low create stencil based shadows. These are shadows that are processed by your CPU, offloading work from your graphics card. It is highly advisable for anyone but those with the weakest of GPU's to raise the setting or completely disable it to avoid these stencil shadows, as Arma is universally always being CPU bottlenecked.

Shadows on medium to Ultra create shadow maps calculated on the GPU, however there are still numerous models in the game that have shadows rendered with stencil instead of the GPU shadow maps. Is there a particular reason why this is so BI? Wouldn't it make sense at this point in time, when CPU bottlenecking is such a big issue, that we fully offload all shadow calculations to the GPU to alleviate some of the rendering stress off the CPU?

Things I have confirmed to use Stencil shadows even on Medium - Ultra Shadows setting:

-Infantry

-Vehicles

-Lamp posts

-Rocks

All of these things and possibly more, should be casting Shadow Maps instead so that the CPU can work on other things. In a game so poorly multithreaded, this unnecessary workload of rendering shadows is just wasting CPU cycles on things that the GPU should be handling. Of course I am no programmer so perhaps this old engine has some issues with doing full shadow maps, but I see no reason why at least static meshes cannot render shadow maps.

Example screenshots how you can tell what's Stencil shadows vs Shadow Maps, Shadow setting is Ultra:

All Shadow maps:

http://imageshack.us/a/img829/3832/2013050500001.jpg

http://imageshack.us/a/img703/4215/2013050500004r.jpg

http://imageshack.us/a/img838/4058/2013050500005.jpg

All Stencil shadows:

http://imageshack.us/a/img703/6167/2013050500003.jpg

http://imageshack.us/a/img689/3281/2013050500006.jpg

Mixed both:

http://imageshack.us/a/img841/8424/2013050500002.jpg

You can tell the difference in that Stencil shadows have hard, often heavily aliased edges where as Shadow maps have soft blurred edges, which is much more realistic.

Another problem with Stencil shadows aside from the fact that they are just another form of wasted CPU cycles, is that they do not function nearly as well as Shadow maps do. For instance, standing underneath a street lamp casting a Stencil shadow, does not have the shadow cast on my first person player model. Example:

Standing under street lamp, shadow over my body and gun, no shadow visible in first person:

http://imageshack.us/a/img543/7227/2013050500007.jpg

Standing under tree, shadow map of branches and leaves appear on my gun:

http://imageshack.us/a/img580/4005/2013050500008.jpg

For these reason I ask that BI consider transitioning to full shadow maps on Medium to Ultra settings for the sake of not only offloading work to GPUs, which at the top end of gaming are starved of work because of CPU bottlenecking, but also to cure some visual artifacts that appear when mixing Stencil shadows with Shadow maps.

Thank you for reading.

Edited January 5, 2014 by DaRkL3AD3R

[old_painless 182]

Nice groundwork! Perhaps a ticket on the feedback tracker could be set up ?

[nodunit 397]

The strange thing about vehicles is that it appears to vary based on the vehicle and camera, for example in first person the offroad has stencil shadows, yet in third person (and looking at it from outside of it) it uses the new method, you can see the same thing in the AH/MH-9, interior uses stencil but from the exterior (or third person?) you can see it uses the new while the pilots are stencil'd. Yet neither the Ifrit nor the Hunter exhibit the new shadows in any way.

Edited May 5, 2013 by NodUnit

[bad benson 1733]

i also noticed that the characters of arma 2 used in arma 3 via AiA have shadowmaps. it seems to work without causing problems.

[metalcraze 290]

BIS needs to use softshadows for everything

No idea why they keep such separation. Character/object shadows will be a part of the same sized shadow map so no loss in quality - only better looks.

[DaRkL3AD3R 1]

Thanks for the posts guys. I haven't made a ticket yet, I'll have to search to make sure there's no others on the topic. Really hope BI just sees this and acknowledges the issue as it really doesn't seem like a lot of work to fix. Probably just a parameter tied to certain entities and models that needs to be updated for the new shadow system. That's a single day's dev build worth of work to be honest, if someone just sat down and did that.

[roberthammer 582]

I think those Stencil shadows are easy to render for our gpu so thats why bis is still using it for the most things but still i liked to see more quality shadows :)

[DaRkL3AD3R 1]

I think those Stencil shadows are easy to render for our gpu so thats why bis is still using it for the most things but still i liked to see more quality shadows :)

Do you understand the current performance dilemma in Arma games?

Things are NOT hard enough for the GPU. Anything that puts more work for the CPU instead of the GPU is a bad thing. We need all the CPU cycles we can get to go towards bumping that minimum framerate. Removing all stencil shadows from the game would alleviate some stress from the CPU and put it on the graphics card. This is exactly what Arma players have been looking for in thousands of posts "low gpu utilization poor fps" well, change your Shadows from Low to Medium and watch not only better shadow graphics but also better FPS because you're using more your GPU instead of processor...

We need full shadow maps... stencil shadows are ancient, almost 10 years old technology when looking at realtime implementation in commercial gaming. Shadow maps are where it's at, and I hope BI fixes this issue.

[metalcraze 290]

For soft shadows there's almost no difference if you will add a character or 10 to the shadow map. It's rendered based on hundreds of other objects at all times anyway.

[jumpinghubert 49]

for me the main problem are the completely not antialiased edges on parts of shadowed objects, soldiers, vehicles http://feedback.arma3.com/view.php?id=1353. In arma2 the soldiers for example are completely antialiased.

[DaRkL3AD3R 1]

for me the main problem are the completely not antialiased edges on parts of shadowed objects, soldiers, vehicles http://feedback.arma3.com/view.php?id=1353. In arma2 the soldiers for example are completely antialiased.

That ticket really should be closed. Shadows cannot be antialiased. They are a texture map at a pretty low resolution, and the only semi proper solution to your jagged edges problem is to increase shadow map resolution. This comes at a tremendous hit on performance and is not worth it. If you want to experience what I'm talking about, load up either Skyrim or Crysis and modify the shadow map resolution to 2048x2048 or 4096x4096 and watch how your FPS plummets compared to the normal 1024x1024.

That also doesn't really have anything to do with this topic, as we're discussing why BI has some assets using archaic shadow technology when they already implemented much newer and more efficient rendering abilities in the same game/engine.

[jumpinghubert 49]

sorry hijacking your thread with this problem. I think we speak about different things, I mean parts of the objects WHEN the sun is shining and IF there is some selfshadowing on the object. Not easy to explain with my crap english. It has nothing to do with shadowresolution because arma2 has well antialiased objects still on sunny day :-)

[DaRkL3AD3R 1]

sorry hijacking your thread with this problem. I think we speak about different things, I mean parts of the objects WHEN the sun is shining and IF there is some selfshadowing on the object. Not easy to explain with my crap english. It has nothing to do with shadowresolution because arma2 has well antialiased objects still on sunny day :-)

That's because Arma 2 uses completely different and ancient shadow rendering technology called Stencil shadows. These types of shadows create hard edges which can be anti-aliased. Shadow maps which are the current and most advanced/efficient form of shadow rendering, cannot be anti-aliased because it works in a completely different manner.

It's okay don't worry about hijacking. But I am just warning you that the only way you can get anti-aliased shadows is if you set Shadows to Low setting and then it will work. But this will hurt your performance a lot and not look as good as soft shadows using the higher setting.

[bad benson 1733]

i always thought that those rough edges on the shadows are really a minor issue. sure fix it if you can but who cares. you'll only notice it when looking for flaws. if you just play and perceive everything in a peripheral way, all you need is consistency and overall good lighting. to me the shadow lod geometry based shadows always looked totally unconvincing because they are always sharp.

[max power 21]

That's because Arma 2 uses completely different and ancient shadow rendering technology called Stencil shadows.

It has both and which it uses most often can be affected by the shadow detail settings.

[DaRkL3AD3R 1]

It has both and which it uses most often can be affected by the shadow detail settings.

I stand corrected. It must have been patched in at some point because I had release Arma 2 and it was purely stencil. Looked really bad.

Either way Arma 3 should continue the trend that the patched Arma 2 and OA have set in motion. We really should be using full Shadow Maps on Medium to Ultra shadow setting, no Stencil shadows whatsoever. Hopefully this is just a bug from the alpha and we can see it eventually get fixed. The sooner the better.

[max power 21]

I stand corrected. It must have been patched in at some point because I had release Arma 2 and it was purely stencil.

Nope. I believe ArmA 1 also had shadow map shadows as well. Which it used was also dependent on your shadow detail settings.

[DaRkL3AD3R 1]

Nope. I believe ArmA 1 also had shadow map shadows as well. Which it used was also dependent on your shadow detail settings.

Irrelevant lol this topic is about Arma 3 using mixed shadows on even Ultra shadow settings when it shouldn't. Let's please not derail this Mr Moderator :P

[NeuroFunker 11]

I think those Stencil shadows are easy to render for our gpu so thats why bis is still using it for the most things but still i liked to see more quality shadows :)

right now, we are CPU limited, right? Stencil shadows being rendered by CPU, where shadows maps by GPU? Wouldn't that be a small solution, to unload our CPUs, by leting our GPUs do the work, with shadow maps?

---------- Post added at 00:17 ---------- Previous post was at 00:16 ----------

Irrelevant lol this topic is about Arma 3 using mixed shadows on even Ultra shadow settings when it shouldn't. Let's please not derail this Mr Moderator :P

rofl @ pointing on moderator, for derailing the thread! Pro-tro-skillz, brah!

[DaRkL3AD3R 1]

right now, we are CPU limited, right? Stencil shadows being rendered by CPU, where shadows maps by GPU? Wouldn't that be a small solution, to unload our CPUs, by leting our GPUs do the work, with shadow maps?

---------- Post added at 00:17 ---------- Previous post was at 00:16 ----------

rofl @ pointing on moderator, for derailing the thread! Pro-tro-skillz, brah!

1) You are correct, it's better to make the GPU do the same work instead of CPU and that can be achieved by switching to pure Shadow Maps and removing all Stencil shadows :D

2) Thanks ;) I am not concerned about old Arma's at this point. After playing the Alpha there is no going back. I want to see A3 be all that it can be and I think changing to full Shadow Maps is a big improvement in performance and graphics.

[Flash Thunder 10]

I have always wondered about this. Overall for the time being I just disable shadows all together not even worth the performance hit.

I do like the recent change to shadows in alpha.

[max power 21]

Irrelevant lol this topic is about Arma 3 using mixed shadows on even Ultra shadow settings when it shouldn't. Let's please not derail this Mr Moderator :P

I was simply pointing out the inaccuracies in your information, Mr. User. You want the information you give out to be accurate, don't you? Or would you rather just sit there and throw out random inaccuracies? I mean, the facts seemed to be important to you when you brought them up.

---------- Post added at 23:20 ---------- Previous post was at 23:18 ----------

I have always wondered about this. Overall for the time being I just disable shadows all together not even worth the performance hit.

I do like the recent change to shadows in alpha.

I think the BI art directors like the look of the stencil shadows better up close because they aren't so blocky and vague. That's just my guess based on how the shadow detail levels behave.

[DaRkL3AD3R 1]

I was simply pointing out the inaccuracies in your information, Mr. User. You want the information you give out to be accurate, don't you? Or would you rather just sit there and throw out random inaccuracies? I mean, the facts seemed to be important to you when you brought them up.

The only inaccuracy I had was that Arma 1 + 2 + OA did have shadow maps that I wasn't aware of. This however IS irrelevant to my original post which is factually correct.

Do you have inside information from the art people in saying they want stencil shadows for vehicles/infantry? Because that still doesn't explain why rocks, signs, guard rails, street lights and various other static meshes are rendering using stencil shadows.

I personally can agree with the first person weapons, and maybe even vehicle cockpits, using Stencil shadows, but there's no reason for world static mesh objects to be using that technique.

PS - Not trying to be a jerk but what techniques past games use really doesn't matter. This is the Arma 3 Alpha and I'm only concerned in going forward. I don't want to derail this thread talking about the older games so let's drop it.

Edited May 8, 2013 by DaRkL3AD3R

[max power 21]

I don't want to derail this thread talking about the older games so let's drop it.

I guess it would behoove one not to bring up things one doesn't want to talk about in the future then :)

[DaRkL3AD3R 1]

I guess it would behoove one not to bring up things one doesn't want to talk about in the future then :)

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