Unity Sprite Uber Shader
An Uber Shader for Unity specialised in rendering Alpha Blended objects like sprites. It has a ton of features and a nifty Shader GUI meaning its very easy to use. It's also modular so features you don't use don't impact performance at all. Because it supports all its feaures in a one pass Vertex lit mode it can be used on skeleon based animation or sprites with submeshes (eg Spine animations) whilst preserving soft alpha edges, this includeds per pixel effects like normal mapping and specular.
Above shows single pass normal mapping, specular, emission and rim lighting on Unity's example robot sprite.
Features
Lighting
The shader supports both multi-pass Pixel Lighting and single-pass Vertex Lighting as well as simple unlit.
Normal/Bump Mapping
The shaders support Normal maps even when using single pass Vertex Lighting. For Normals maps to work you need a mesh with Tangents.
Blend Modes
The shaders support easily changing the blend mode between Opaque, Standard Alpha, Pre Multiplied Alpha, Additive, Soft Additive, Multiply and Multiply x2 blending modes.
Depth Writing
The shaders allow you to optionally write to depth using a Cutoff alpha value. Included are also several shaders that can be used by a camera to render a Depth or DepthNormals texture with soft edged Depth rendered for objects using these shaders that don't write to depth. Meaning you can have Post Effects like Depth of field or Ambient Obscurance working with soft edged sprites.
Specular
The shaders optionally support physically based BRDF specular in both Pixel Lit and single-pass Vertex Lit lighting modes. This is based off the metallic specular in Unity's Standard Shader. (It uses a Metallic Gloss Map and a Smoothness Value).
Emission
The shaders optionally support an Emission map in both Pixel Lit and single-pass Vertex Lit lighting modes. This again mimics Unity's Standard Shader.
Fixed Normals
The shaders optionally support using a Fixed Normal instead of Mesh Normals. This can be usefull for rendering objects that don't have normals (like a TextMesh for example). Also sprites can use a view-space Fixed Normal to make it look less flat than using its own normal when it rotates around the Y axis. (it stop's it looking like a sheet of paper because it tricks the lighting into thinking its still facing the same way). When using a fixed normal the shaders can also automatically flip the tangents of a mesh if its rendering the wrong side of it, meaning normal maps can work for both front and back faces.
Shadows
Shadows are supported in all lighting modes (including unlit) using an alpha cutoff value.
Fog
Fog is optionally supported and works correctly with all blend modes.
Gradient based Ambient lighting
The shaders optionally support using Spherical Harmonics for ambient lighting. In Vertex Lit mode, the Spherical Harmonics is approximated from the ground, equator and sky ambient colors.
Color Adjustment
The shaders allow optional adjustment of hue / saturation and brightness as well as applying a solid color overlay effect this can be used for things like damage effects etc.
Rim Lighting
The shaders allow optional camera-space rim lighting in both lighting modes.
How To Use
Copy the SpriteShaders folder to anywhere inside your Unity Assets folder. On your objects material click the drop down for shader and select either Sprite (Pixel Lit), Sprite (Vertex Lit) or Sprite (Unlit).
Material Property Names
Below are some of the Material Property Names/IDs that are commonly animated from code. You can use these in conjunction with Unity's MaterialPropertyBlock API (MaterialPropertyBlock, Renderer.SetPropreryBlock) to override property value sper renderer. You can also use these with Shader.PropertyToID.
Main Maps
Albedo/Main Texture: (Texture2D) _MainTex (Color) _Color
Normal Map: (Texture2D) _BumpMap , (float) _BumpScale
Diffuse Ramp: (Texture2D) _DiffuseRamp
Secondary Albedo/Blend Texture: (Texture2D) _BlendTexture , (float) _BlendAmount
Specular
Metallic Gloss Map: (Texture2D) _MetallicGlossMap , (float) _GlossMapScale
Smoothness: (float) _Glossiness
Emission
Emission: (Texture2D) _EmissionMap , (Color) _EmissionColor
Emission Power: (float) _EmissionPower
Color Adjustment
Overlay Color: (Color) _OverlayColor
Hue: (float) _Hue
Saturation: (float) _Saturation
Brightness: (float) _Brightness
Rim Lighting
Rim Color: (Color) _RimColor
Rim Power: (float) _RimPower
You can see a more complete list of the material properties by selecting the relevant Shader asset in your Project View and looking at its Inspector. Note that the list of properties may not show up in the inspector if your project has a script that overrides Shader asset inspectors. Some third-party Shader editors such as ShaderForge do this.
Known Issues
When using Unity's Sprite Renderer class, its tangents are incorrect when you use the flip X or flip Y flags. This results in incorrect lighting when using normal maps. If you want to use these shaders with a normal map on a Sprite Renderer then either set a negative scale on the objects transform or rotate it instead (with back face culling turned off).