Symmasolan's PBR-Lite Cel Shader (for Unity BiRP)

An elegant, lightweight PBR-lite Surface Cel Shader for Unity BiRP

Features:

• Built-in Render Pipeline (BiRP) Support (Unity 2019.4+).
  • Works with both Forward and Deferred rendering!
• Cel-shaded stylized lighting with PBR-lite surface options like:
  • Normal map
  • Metallic and Smoothness maps
  • Height map
  • Occlusion map
  • Emissive map
• Basic Outline support (Reverse Hull, unlit).
  • Note: Outline shader variants only function in Forward rendering.
• Forward Rendering Ambient Spherical Harmonics support for real-time and baked lighting.
• Included variants for:
  • Opaque (& Outline)
  • Transparent (& Outline)
  • Transparent Cutout (& Outline)
• Support for as many Pixel Lights as your project allows for in quality settings!
• Support for up to 4 Vertex/Unimportant Point Lights.
• Highly customizable per-material with a user-friendly interface for each property (LWGUI).
• Exposed variables for advanced rendering options, including:
  • Blend RGB, Blend Alpha, and their respective basic BlendOps
  • Stencil Buffer values
  • Depth ZWrite, ZTest, and Offset
  • Alpha to Coverage
  • Color Mask
  • Cull Mode

Limitations:

• The Outline currently only supports:
  • Forward Rendering. The outlines do not function in Deferred rendering due to pipeline differences in how the resulting shader is rendered.
  • Transparent Cutout Outline for Opaque/Transparent Cutout material types
  • Transparent Outline for Transparent material types.
    • Supporting both basic render types (Opaque, Transparent) for the Outline is planned to be expanded upon and supported somewhere in the future.
• Only supports up to 4 Vertex/Unimportant lights per surface maximum for Forward rendering due to base Unity shader functionality/limitations.
• Spot Light Vertex lights are unsupported.
  • They are possible to support, but would require a particularly cursed implementation that doesn't always function as intended/desired in Forward/Deferred rendering. There are no plans to support them at this time.
• Currently, Pixel and Vertex lights do not visibly mix well when overlapping, often producing a visible artifact.
• RGB and Alpha BlendOp enums are currently just the basic selection (D3D11 & Advanced OpenGL BlendOps removed) due to current LWGUI limitations.
• Use of a different ShaderGUI/CustomEditor that is not LWGUI (the project's implemented CustomEditor) would require significant extra footwork.
• The "KeyWords: System.String[] or Index: 15 Error!", error, is an LWGUI error of unknown nature, and has been reported to the developer. It does not prevent you from compiling scripts or building.

Installation:

• Double-click the downloaded `.unitypackage` to Import it.
  • If that does not work, you can also drag and drop it into your open project.
• In your project explorer, right-click -> Create -> Material.
• Selecting the newly made Material, there is a drop-down at the top of the Inspector that currently says "Standard". Select the dropdown, and find the included shaders under the "Symm/*" folder. Select the shader variant you wish for this Material to use!
  • Note: There are tooltips for most of the parameters in the editor that tell you what that thing does! Hover your mouse over any parameter and a small tooltip box will appear if that parameter has a tooltip to display.
    • Note about the Note: The tooltips seem to break sometimes on initial inclusion to the project. Restarting Unity seems to fix this (most of the time).

Licensing and Terms of Service:

• I do not take any responsibility for any possible damage that this shader can cause/causes.
• All sales (free, with donation, or otherwise) are final, and cannot be refunded as this is a digital product.
• Do not claim this shader as your own work. It'd be cool if you credited me where possible (I've put a lot of time and love into this!), but is not required.
  • Additional information sources are available within the shader's source code and/or from the ASE graph.
• DO NOT remove source comments from the shader, either in the Amplify graph, Amplify metadata, or in the final shader's text file.
• You are allowed to edit and customize the shader for your own personal use. (Effectively requires Amplify Shader Editor [v1.9.1.5+] to make significant changes easily)

All this said, the included code is all MIT licensed and the package is free. Tag me on twitter (@Symmasolan) with your cool creations using it! 

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Not distributed with the project are the textures shown in the screenshots above. Here's a short list of what they are and where to get them!

• Opal_Fish_Tiles texture set by my good friend, Vulcure! (No socials, sorry!)
• Stylized_13_Roof texture set from:
  • Texture Pack: Stylized 02 by JulioV
• StylizedWoodPlanks_04 texture set from:
  • Stylized PBR Wood Planks Textures by Neurotremolo
    

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Un-ending thank yous to the following amazing people who directly helped this project come to life:

• Vulcure
  • For being a motivational engine and supporting me at every difficult turn in the project. This project would not have been completed without seeing the cool watercolor textures he created during pre-alpha when I was still figuring all the magical math out.
• Tap
  • For getting me into contact with the first person interested in testing the shader!
• Ether Trogg (Sekathi)
  • For helping with rigorous testing and giving constant amazing feedback through the later stages of the project's pre-alpha and beta cycle.
• aiLar
  • For testing out the Shader through various versions on their own personal work.

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Known Issues:

• None currently!

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Recent Changelog:

• v2-01-01:
  • Fixed Opaque Outline using the wrong type of Outline masking.
  • Fixed Transparent texture being pure white by default. Changed to gray.
    • With this, I realized that there's a need for a Main Texture tint value. This minor feature will be added in the near future!
  • Fixed issue with missing LWGUI files from previous release.
• v2-01-00:
  • Re-added the Transparent shader variants.
  • Fixed "Alpha to Coverage" for Opaque variants.