Fenglvv's Toon Shader

Introduction

Shader features

• Outer stroke: use script to smooth normals and transform to tangent space, record to vertex color rgb, use alpha to control stroke thickness
  Inside stroke: The screen space compares the model depth to the surrounding depth, and exceeds the threshold to draw an outside stroke
  Basic coloring: Lambert + GGX highlights + ambient CubeMap + dark overlay gradient mapping
  
  
• SDF Face Shadow: Calculate the step value using the Angle between the character's forward direction and the light, dividing the SDF map into shaded and unshaded areas
  Eyebrows through the hair: Write the hair and face into the template, with the eyebrows drawn at the end, above the face and hair
  Screen Space Fringe Shadow: Write the face to the template, offset the hair along the direction of the light, and draw the shadow color on the template area
  
  
• Use the Vertex Color alpha channel to control the outer stroke thickness and trim the character's hair and face strokes
  
  
• Normals remap to optimize the highlight shape
  The hair normal is mapped to a near-spherical shape to avoid the split between bright and dark bangs and get a smooth distribution of light and dark hair
  
  
• Draw a Flow Map for the hair along the direction of the highlight flow, convert it to the Tangent space and store it in the map
  Drawing Double-layer highlights using the kajiya-kay method
  
  
• Use the parallax mapping to draw the eyeball so that it appears to have depth
  
  
• Use a shadow camera in the same direction as Directional Light to separately record the depth of a specific tag object, and compare the depth of the shadow camera in shader to achieve high-precision character self-projection