themasonx/unitypcss

Nvidia's PCSS soft shadow algorithm implemented in Unity

UnityPCSS

Nvidia's PCSS soft shadow algorithm implemented in Unity3D.

Description

"PCSS" or "Percentage Closer Soft Shadows" is a shadow sampling algorithm invented by Nvidia in 2005 (Original Whitepaper). The intent is to simulate a more realistic falloff where the shadows get progressively softer the further the receiver is from the caster.

This effect is easy to spot in real life, such as when looking at tree shadows:

I thought this photo was really cool, so I did a quick recreation as a test:

Current Limitations

Currently only works with "Directional" light sources, as it's primarily an override of the "Screen Space Shadows" shader in the graphics settings, but I'm looking into the possibility of directly overriding the actual "UnityShadowLibrary.cginc" to affect "Spot" and "Point" lights if possible.

Version Compatibility

Currently working in 2019, though the shadows themselves should still work with 5.5, 5.6, 2017, and 2018 (no modifications necessary, it automatically detects and adapts to any version), but as this is now a Unity 2019.2 project, the materials in the demo scene do not import correctly in earlier versions. There are only 3 or so materials that need their albedo/metallic/specular textures assigned from the nearby "Textures" folder, so it's not that bad, but if anybody has any ideas to fix this, please let me know! :)

Future Development

This asset and any improvements will remain free (both as in beer and speech), but if you wish to support me spending extra time on this, you can donate to me through PayPal. NOTE: Please do not feel pressured to donate it's just an option if anyone wishes to support me spending more time on this, and less on my game, which I can't even use it for.

I obviously didn't do this to make money though; instead, I'd prefer support in the form of you guys contributing back any fixes/improvements, so that we can all benefit :) I made it Open Source rather than just a free asset because I believe that if we work together, we can create something truly amazing. Thanks for the interest, and I hope you guys get some good use out of it! Let me know if you have any issues or ideas, and I'll respond to pull requests ASAP.

unitypcss's Issues

When making a build, it does not work any more:

When I build the project, I dont get the PCSS, but it seems as if the shadows fall back to the Unity standard soft shadows.

When we remove the function: ResetShadowMode(), the shadows work also in the build. Could you isolate and solve the problem?

Not working

Shaders are giving error in unity 5.6.0f1!!

Directional Shadows Messed Up

After adding PCSS and turning on realtime GI shadows started changing resolution randomly and light started bleeding frequently. When I turn camera at some specific angle shadows become blurry and very low res no matter the quality settings.

I can't return shadows back to normal even when I remove PCSS folder and disable GI. This also affects all projects including new empty ones so I'd like to know how to restore default directional shadows. Point and spot lights are normal.

Link to Youtube https://www.youtube.com/watch?v=xRB6QEwvwgE

HDRP

Hey there! Do you think it would be possible to integrate this into HDRP? Not as an asset, but inside HDRP itself.

lack of unitypackage in the release tab

Hope I'm not passing as a jerk but I find the presence of the unitypackage in the release tab a must for unity assets.
Thank you for considering ^^ and kudos on the awesome asset anyway
cheers

PCSS doesn't work in builds

We've tested this in several versions of Unity (5.5, 5.6.0, 5.6.4, 2017.3) and it looks like PCSS is never applied in builds - only standard Unity shadows are visible. All references are correct at runtime (RT is non null, same light is shadow casting in same mode, etc.), and are no errors raised in the logs, so we're a bit stumped as to how to debug this. What might be the reason for shadows working perfectly in editor but disappearing in the final application?

In case that's relevant: we're using Windows 10, Nvidia GPUs, DX11, linear lighting and deferred rendering with aforementioned versions of Unity.

[Fixed] Broken in 2017.1

There's simply little to no effect. No PCSS is being applied. Definitely worked in 5.6.

HFTS?

Have you seen this? It seems to be a far better technique: https://developer.nvidia.com/Hybrid-Frustum-Traced-Shadows

Would this be easy to implement into the current system? Please and thank you for any answers :)