CSCI 580 Final Project — Toon Shader (CPU Ray Tracer)

Toon Shading with Ramp, Diffuse, Hard-Edge Specular, Rim Light, and Dual Outlines

Team

• Haoran Jia — Haoranji@usc.edu banded specular + rim light tuning, integration/support
• Shengjie Lin — slin0570@usc.edu rim integration, cleanup/documentation
• Weibo Xu — weiboxu@usc.edu ramp diffuse, depth buffer + depth edge support
• Raymond Zhang — yanzhezh@usc.edu toon shader core, silhouette integration

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Overview

This project extends the CSCI 580 ray tracing homework framework with a stylized toon shading model.
We replace the original shading, adjust several modules, and add a depth-based post-processing step since the original pipeline does not provide a depth buffer.

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Features

• Toon diffuse with color ramp (colors + positions)
• Hard-Edge Specular with two thresholds
• Rim Light (Fresnel-like, view-dependent)
• Outlines
  • Silhouette using |N·V|
  • Depth Edge using Sobel on a generated depth buffer
• OBJ mesh support + basic primitives (e.g., spheres)

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Pipeline (High-Level)

1. Set up camera and allocate buffers
2. Parse OBJ into triangles (retain simple primitives)
3. Fire primary rays → intersection → toon shading
4. Fill fragment buffer
5. Apply depth-based outline post-process in place

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Key Parameters

Configured in main.cpp via ToonParams:

• Ramp: rampColors, rampPositions
• Specular: specularThreshold1/2, specColorA/B, material shininess
• Rim: enableRim, rimColor, rimIntensity, rimPower, rimThreshold
• Outlines: silhouetteThreshold, outlineColor, enableDepthEdges, depthEdgeThreshold

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Build & Run

clang++ -std=gnu++17 -O2 src/*.cpp -o toon
./toon