[Next-Gen Soft-Shadows 2] Sophisticated dynamic penumbra Shadows for Unity

I've included some quick profiling in the v.1.9.0 video but here is a more realistic approach (without the GPU profiling overhead):


Performance got increased by a huge marge!
I was doing something funny with the number of samplers when the camera was close to a surface where the algorithm will generate 600+ samplers per pixel, overkill! This explain the strange slowdowns people had when looking down.
Thanks to @larsbertram1 that brought back the long forgotten issue.
Also the same view dependency I had in my algorithm produced stretched raysteps, it was a tad ugly and unpredictable. No more of that either!

 

Folks,
Version 1.9.0 is out and just submitted v1.9.1 to the Store. I forgot one little detail with the new Bilateral Contact Shadows and it was adjusting the kernel size over distance, so far away objects won't display the same amount of softness as close range objects.
If you can't wait for the update, open NGSS_ContactShadows.shader go to line 220 (before for loop) and paste this:
offsets /= depth;
The rest of the additions are related to optimizations.

Features and changes v1.9.1:
- More optimizations for Bilateral Contact Shadows
- Sampling scale over distance. Makes far away shadows less detailed than close range ones
- Bilateral kernel size over distance. Makes far away shadows less softer than close range ones

[EDIT] NGSS v1.9.1 is out on the store!

 

Hi,
I bought NGSS yesterday, visually everything seems to be working pretty well, but I have some issues with performance.
Scenes in my game where I normally would get around a 100 fps (GTX 1080 @ 1440p) now crawls down to as low as 15-20 fps on the same settings. Changing shadows to Hard and Low Resolution helps a bit but still cuts performance down by more than half. I've tried turning off all other effects like volumetric lighting and processing but that didn't help. I have to admit I probably don't have the most optimized game out there but I feel like these kinds of frame times with NGSS enabled aren't quite as intented.

Unity:


NGSS:


I only really use point lights and spot lights in my scenes (everything is indoors), and I do use a lot of mixed and realtime lights since volumetric lighting is a big part of my game. I'm running Unity 2018.3.0b3. If you need any other info please let me know

 

@luuktito
Unity local shadows cannot be considered soft as they only do 4 taps PCF. NGSS by default does 64 taps PCSS (optimized with early bail out algorithms to sample only the penumbra area) but still both are very different and they cannot be compared visually/performance-wise. So yeah, with local lights, Unity is faster cause it's close to be a hard-shadows method. A good comparison performance wise is Unity Directional Soft-shadows vs NGSS Directional Soft-shadows (with PCSS off).
Still the performance hit you are having is kinda strange. NGSS is being used in lot of commercial games, some of them are very large open world games with zillions dynamic lighting, Rust from Facepunch is one of them and I've never saw such slowdowns unless you are already GPU bound?
Can you pack one of those scenes that shows the issue and send it to me (google drive or dropbox) so I can deep profile it on my end?

 

Heads up onto raytracing and NGSS (HDRP renderer).
Just received my new RTX 2080 but still waiting for Unity DXR integration to implement all my tests projects from nVIDIA Optix into Unity. Hopefully I will ship NGSS HDRP with the new raytraced shadows. I got a crazy sh*ton ideas and hybrid effects (gbuffer + raytrace) to try in Unity!

Furtermore I have plans for all this (sometime in 2019, cause now I need to finish NGSS 2.0 products first):
- NGAO (Next-Gen Ambient Occlusion)
- NGRR (Next-Gen Raytraced Reflections)
- NGGI (Next-Gen Global Illumination)

NGPT (Next-Gen Path Trace)?

 

The NGSS Contact Shadows component on my camera disables itself after a short time. I'm in 2018.3b3 on a mac.
Any ideas what is going on?

 

That's a great roadmap!

 

@transat
Make sure to set your game camera Rendering Path to either Forward or Deferred. If it's set to "Use Graphics Settings" or something the script will disable itself. The script also log a console warning message about the Rendering Path before disabling itself.

[EDIT]
Normally, Use Graphics Settings should not disable the Script, that was silly on my part. I've already changed that behaviour for the next patch update (v1.9.2) to detect only if Rendering Path is set to Vertex Lit which is the only path it doesn't support.

 

I enabled it but it doesn't have any effect on neither my iOS device nor the editor with iOS as the selected platform.

 

@halilkayim
Are you using GLES 2.0 as target renderer? If so it won't work. Minimum SM is 3.0 which GLES 2.0 doesn't support.
Other than that, it's really your Project Graphics Settings Cascaded Shadows being disabled. By default is disabled on mobile.

 

Yeah you were right. I was looking at the Quality Settings instead of Graphics Settings. I enabled it now on Graphics Tier 2 and the shadows look great on my iPhone!

 

I'm trying to get really high quality global shadowing in Unity using NGSS directional & NGSS contact shadows and for the most part it looks really good. The only problem I'm having is trying to get rid of shadow acne in cascades 3/4, e.g.

I have my shadow bias set to 0.3, normal bias 0.0 and global softness 1.0, obviously just increasing bias or reducing softness removes the acne, but introduces other artifacts. My camera is normally looking across the terrain, but if I am looking down on the terrain the effect is far worse.
Is there any way I can modify the softness or bias per cascade to try and remove this? Anything else I could try?

 

@roland-xpi,
You can try enabling PCSS and/or reduce the softness a bit.
Unfortunately, shadowmap artifacts cannot be entirely removed, only mitigated.
PS: Try all that in a game scene, empty white scene is super easy to spot shadows imperfections.

 

@tatoforever thanks for your quick response, I tried PCSS and that did reduce the general appearance of the artifacts but still had the problems in some areas, and performance was lower as you'd expect. In our test db (lots of low contrast flat surfaces) the effect is very obvious like the image, but in our terrains it's a more subtle encroaching shadow. I'll try balancing the softness / bias to minimise the most obvious effects and performance testing PCSS again.

 

Did you tried rising the bias and enabling ContactShadows? This combo can help, hence the whole idea of contact shadows is to help with peter panning (side effect of removing shadows acne).

 

@tatoforever I have contact shadows enabled, but to fix the shadow acne with global softness = 1.0 I have to set the bias to ~1.0, which contact shadows can't compensate for as a load of artifacts start appearing, which then require increasing contact shadow width etc.
So I think I'll try increasing bias a bit, adding a tiny amount of normal bias and if that doesn't do enough I'll try enabling PCSS and see how it affects performance again, hopefully I'll manage to get a good enough balance between appearance, aliasing, acne and performance with those.
Thanks for the suggestions

 

I am trying to create a shader that only renders the directional soft shadows and the albedo color but does not apply any specular, diffuse and ambient lighting.

I can do this with a fragment / vertex shader and forward rendering path but that does not create the soft shadows.


With a surface shader I managed to disable the lighting but that also disables the shadows.


Just for reference, here is an image of the soft shadow working with a standard surface shader + deferred rendering.


Any suggestions to how I can achieve an unlit shading effect with NGSS soft shadows would be much appreciated.

 

@mrkhnstn
Find the modified shader attached. It will work will forward, deferred, local and directional shadows. You can add ambient by removing the noambient pragma directive.
Tested with example scene from NGSS:

 

I noticed a new version 1.9.1 is out. Does it support semi transparent shadows now?

Thanks,

Alejandro.

 

@tatoforever
Thanks for the swift response! The shadows show up now with your modified shader but unfortunately
they are hard.




Wondering whether there is something wrong with my NGSS setup. With a standard surface shader I only see the soft penumbra with the rendering path set to deferred. I never see any soft penumbra with forward rendering.

I am on Unity 2018.2.9f1 on a Mac and targeting iOS. My Graphics and Quality Settings below.

[Edit]
It seems to be an iOS platform issue. When I switch to PC, MacOS and Linux Standalone the soft shadows show up in forward and deferred mode.

[SOLVED]
My bad. Had to switch on Cascaded Shadows in the Mobile tap of the Tier Settings in Graphics Settings. It all works now in forward and deferred rendering on iOS platform. Thanks again for swift response!

 

Semi-Transparent surfaces casting shadows have been there since ~Unity 5. If you mean, semi-transparent materials that receive shadows then no, because NGSS 1 uses Unity internal depth maps and render files which where designed like this.
You can still create a custom shader that receives shadows in a hacky way like we did (rusty leaks on the walls and spider web):

Basically, the provided shader, does AlphaBlending (to soft the edges of the Cutoff) and decal blending to properly blend semi-transparent part of the surface. The shadow receiving is attained with the AlphaTest trick. You can experiment with different Rendering Queues, the one that works the best is AlphaTest. Is not bullet prof but it works most of the time. Just avoid putting a huge transparent plane in the middle of the scene and you should be fine. This works best with materials that goes on top of other surfaces.
The proper way to have semi-transparent surfaces receive shadows is to alter the internal rendering files but I just don't have time for that now. Sadly.
PS: This shot is from our game, it also uses NGSS and it's coming to consoles next year.
Enjoy!

 

Hi,
I really like your soft shadow solution and am currently trying to use it to help objects in an ARKit scene to blend in better with the rest.
Performance is totally ok when disabling PCSS and using only a single cascade.

But there is a bug that I don't really understand enough to troubleshoot any further and thought maybe you could help.

On an iPad (2017 with iOS 12.1) the shadow shows up fine and looks like this:

But on iPhone (tested with 7 and 8) the shadow is somehow too far away and also gets drawn on top of the emitting object:



I can not reproduce this behavior in editor even when changing tier of the hardware emulation.

maybe you have an idea to point me in the right direction.

Thanks,
Philipp

 

@iamfist
This looks like a matrix projection bug (with shadows coordinates) or Unity is doing something funny with depth reversion on those devices.
Did you tried with stock Unity shadows?

 

Yes, I tried that. Just to make sure I made a build again where I only disabled the NGSS component on the light.
The stock shadows work as expected.

 

@iamfist
Can you provide a repro project to support?
What version of Unity are you building your project?

 

I tried Unity 2018.1.6f1 and 218.8.12f2 but it is the same for both. I would have to reate a sample project without customer data but I there is not much going on with the camera so I think it will happen in any project on iPhone 7 and 8.

 

Fake penumbra distance based soft shadows for local lights coming in the next update (v1.9.2).
It makes your uniformly based PCF shadows looks better as shadows softness scale with distance:


A bit hard to see but the shadows casted by the character on the wall is ultra super soft and the ones on his clothes are less softer (similar to how PCSS behaves).
The best is that is super cheap, only 2 simple math operations on top of PCF code.
You can turn this new option on/off by commenting a line on the provided shadow library (by default will be on).
Also fixed an issue with local PCSS shadows and 16/25 samplers option if early bail out was enabled.
Let me know what you think.
PS: In this example I'm using only 16 samplers and this game is for Nintendo Switch!

@iamfist
I have a new version that will be submited later today that might fixed your issue. Would you like to give it a go?

 

Along with the rest of additions in next update, there's new shadows visuals and performance improvements coming in v1.9.2. Guess how many samplers we have here?

Only 16 samplers!
Imagine how 32 and 64 versions looks...

PS: I will submit the update on Sunday night.

 

The new shadowing algorithms im adding to next update creates the disks on the fly, with kernels evenly distributed in a way that reduces empty spaces a lot more (less noisy). So the default quality now is 25 samplers as it looks close to the old 64 samplers and the 16 samplers looks better than 32 samplers.
Another nice side effect of the new algorithm is that blocker search for PCSS is speeded up by 4x and doesn't produce any artefacts anymore because the on the fly generated disk maps exactly to the early bailed out frag coords (if the frag bails out = it will map the resulting test 1:1). So it's internally enabled by default and removed from the directional component. Overall everything looks prettier and is a lot faster.

On top of all that, Im trying to get it working with Gather functions but need to rethink a way to make it work the new algorithm with (no promise on that).
PS: This improvement also comes to local shadows.

 

When you say the disks are generated on the fly, is that during the pass? or at runtime? It sounds like that would be slower to do, not faster. But maybe I don't quite understand.

 

@ceebeee
During the shadows rendering. It is a couple of maths operations more compared to the poison disks but the result is higher quality shadows with less amount of samplers per frag which translates to huge performance gains.
Maths operations are always faster than sampling + all the operations that comes with. The gains are quite noticeable.
Here is a visual comparison with the new shadows (16 and 64 samplers):
https://drive.google.com/open?id=1JbASXnDx6UnRYcxbocMjHNk8Kr4PxArU
There's some compression in the video, hope you can spot the changes.

 

Is there anything special I need to do or avoid doing to get Directional PCSS to work? Checking and unchecking PCSS_ENABLED does absolutely nothing, neither does tweaking the max and min values.

 

@halilkayim
PCSS requires a minimum of SM3.5 for inline sampling support. Make sure your target APIs support SM3.5 otherwise PCF will be forced internally.

 

@tatoforever My game has large forests (Vegetation Studio) and I'm getting a lot of flickering and poor performance with Unity's (5.6.4f1) built-in shadow system. I'm developing on an older PC with a nVidia GeForce GTX GPU.

A couple questions about PCSS:

• Do you know if it will work with Vegetation Studio?
• Can I expect performance (frames, cpu, tris) improvements over Unity shadows?

Thanks!

[Edit] - After reading more closely and watching the videos, I don't see any reason why it wouldn't work with Vegetation Studio

 

@wwg,
If vegetation studio works with Unity stock shadows then it will work with NGSS.
You can get similar performance with NGSS Directional shadows (depending on the settings and quality). For local shadows no, you won't have any performance benefit as local shadows in Unity are 4tap shadows vs 16taps which is the lowest setting in NGSS. Still they will look way better than stock Unity shadows anytime.
Shadows is something people underestimate a lot in Unity and the reason is because they are not used to have pretty shadows in Unity so people tends to crank everything else up and leave little to no resources to shadows. If you are already GPU bound it won't help.
Let me know if you have any other question.

 

@tatoforever Thanks for the quick response! I bought NGSS and I'm playing around with it now. Shadows look great and seem to perform at (or above) stock shadows. I was hoping for a major performance increase over stock.

One problem I'm seeing with both stock and NGSS is bad flickering as the shadow distance increases. At a distance of 30 they are pretty stable, but they get really bad as I go over 100. Do you have any tips? I'm still using Unity 5.6.4f1. Perhaps it's time to upgrade to U 2018?

 

You should upgrade at least to Unity 2017 where NGSS support PCSS. Below that there's no inline sampling support which is required for PCSS.
Wait for next NGSS update (to be submited for review this week). I rewrote all shadows algorithms thus improved quality and performance a lot more. Also implemented a new trick that I called "cascade stitching" in which i match cascades soft-ness without resampling next cascade and it's only 2 cheaps math operations. Here is an example (notice that cascade blending is disabled in the component):

I made the shadows completly dark so the effect can be seen better.

 

Folks, new Cascaded Shadows in v1.9.5:

Notice at the end of the video the total absence of Cascade Blending and the stitching algorithm (which count only 3 maths operations) still holding them right. Also the algorithm makes PCF usable and removes acne and artifacts from successive cascades.
Btw, not just directional shadows, all shadows algorithms have been rewritten from scratch. If you diff all NGSS files you will see they are completely different! This alone can be a v2.0 but I give it for free to existing users!
I'm finalizing documentation and will soon submit for review.

 

Very impressive!

 

Nice, any chance to get the update via mail already?^^ (via paypal invoice etc.)

 

@Zyblade,
Lol I'm almost done, it should be ready today. You can bomb support afterwards!
Will keep you folks updated.

 

Alright

 

I love you

 

Looks amazing! However I'm confused how you enable/disable it. In both videos your mouse just flys offscreen and it changes. Where are you enabling the feature at?

Also should this be used instead of Cascade blending, or with it, if you use both will there be problems?

 

He probably just uncommented the necessary lines to activate the effect for the showcase. I think there will be checkboxes later on.

 

@ceebeee
As @Zyblade mentioned, by commenting 1 line in the shadows code to enable/disable. This feature will be enabled by default as it cost nothing (couple of maths operation) and in some situations you can disable entirely cascade blending, making the shadows a lot faster (on top of the new optimizations).
How this technique works? In cascade shadowmapping there's discrepancy of shadows kernels as subsequent cascades are smaller in the shawdowmap thus creates softer shadows exponentially for every cascade (notice this effect at the beginning of the video). What I do is based on cascade distances I try to match softness distribution across splits.
How it looks so nice? Well, I get the cascade distribution values from Unity and scale kernels over distance with that value. So it works any any number of cascades, softness or shadowmap size, etc.

[EDIT] Worth notice that if you are not GPU bound, then crank shadows quality up to suit your artistic needs, don't be shy.

 

^very impressive, I could not identify the blend threshold at all in the attached video

 

Folks,
Version v1.9.5 is finished. I'm updating the documentation and making sure everything is alright, I'll do the submission tomorrow and start taking your request if you can't wait till next week.
Here is another demonstration of no Cascade Blending at all, only using my stitching technique:

As you can see in the video, you can ditch cascade blending entirely if you carefully set it up and optimize your shadows rendering even further.
Also notice the new additions to the Directional shadows in the inspector. Lot of customization, visual improvements and optimizations. Far cascades reduces the sampling amount automatically. This is made possible in combination with the stitching technique further away shadows are less blurry thus requires less sampling (kernels are close to each other).
I also added a Global_Softness_Normalization scale value in case you don't want any stitching (match softness across cascades). Added the ability to tweak both test/blocker search samplers and filtering samplers (up to 128). The test sampling dont need that much sampling, so don't go crazy on it.
Lastly, I added a force_hard_shadows property in case you don't want any soft shadows and don't want to remove NGSS_Component. Useful to do changes at runtime.
Ultimatelly, all property is self-documented, just hover your mouse to display the tips.
PS: Now go back and show me your kick ass projects running NGSS!

 

NGSS v1.9.5 just got submitted for review. Features and changes:
- Complete rewriting of all shadows algorithms. In overall shadows now looks better with similar or better performance (depending on hardware)
- You can now tweak all your Directional Shadows settings through the NGSS_Directional component, including cascades properties and shadowmap resolution
- Cascade Stitching. A ground breaking technique that normalizes shadows softness across cascades
- Ability to chose any sample amount for filtering and test/blocker search. Can go as little as 4 samplers up to 128
- Samplers over distance scale for Directional Shadows. The far away the fragment, the less samplers it requires. This saves filtering a lot!
- Samplers over softness scale for Local Shadows. On top of the cache optimization, if you reduce softness on your lights you will be able to render more lights at once.
- Early bailing out optimizations now produces artifacts free shadows and it's internally enabled by default
- Added support to PCSS on mobile and WebGL2.0 platforms Features and changes
- Addition of Screen Space grid patterns on Directional Shadows to stabilized shadows jittery a lot more (disabled by default as currently not so great, look nice at close up but fades to noisy patterns over distance, will get a major improvement in NGSS 2.0 alongside new shiny things)
- Updated documentation

I probably missed other non that much important highlights of the update but you can bomb support now if you want access to it before it hit the stores. I'll take your requests tomorrow morning!
PS: Happy Halloween.

 

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ps: Thanks for this awesome update =)