Whitted Ray Tracer – Portfolio of Adam Badke

This project gave me my first taste of rendering. It began as an assignment for SFU’s “Introduction to Computer Graphics” course (CMPT 361); I was tasked with writing a basic software 3D renderer capable of performing Phong, Gouraud & flat shading over a span of 10 weeks.

I enjoyed this project so much that I decided to expand it by implementing ray-traced shadows & reflections similar to those described in Whitted’s 1980 paper An Improved Illumination Model for Shaded Display.

This program was written from scratch in C++. Use of external libraries was restricted to minor use of the C++ STL (Standard Template Library), and the QT framework for GUI windowing and pixel set/get operations. All other functionality was created specifically for this project.

GitHub Repository: https://github.com/b1skit/RayTracingRenderer

Sample Renders:

Shading models — A render of four spheres, demonstrating wireframe, flat shading, Gouraud shading & Phong shading

Ray traced sphere reflections — A demonstration of ray traced reflections between sphere objects

A black and white ray traced render of a Ferrari California. Model credit: https://free3d.com/3d-model/ferrari-california-93936.html

Ray traced primitives — A ray traced render of cubes, cylinders, spheres, a torus, capsule, cone and the classic Utah teapot

The Stanford Bunny — A render of the classic 3D scanned Standford Bunny model. Model credit: http://graphics.stanford.edu/data/3Dscanrep/

Vertex color bilinear interpolation — A render of 7 cubes demonstrating bilinear interpolation of vertex colors

Specular highlights — A demonstration of various specular highlights that can be achieved by combining different specular exponent and coefficient values

Renderer Features:

Basic Rasterization:
- Triangle filling
- Line drawing
- Wireframe rendering
- Object transformations via matrices (Translation, rotation, scale of polygons, cameras & lights)
- Bi-linear interpolation (Perspective correct color & normal interpolation)
- Adjustable camera frustum/FOV (Field Of View) settings
Shading Techniques:
- Flat/faceted shading (Lighting calculated once per face & applied to all vertices)
- Gouraud shading (Lighting calculated once per vertex & interpolated across faces)
- Phong shading (Per-pixel lighting)
Lighting:
- Ray traced reflections & shadows
- Point lights (User-controlled world space position, color & attenuation)
- Ambient scene lighting
- Depth cued distance fog
File Interpreter:
- Compatible with Wavefront 3D object format (.obj)
- 3D Scenes of can be fully constructed & controlled using a custom “simple” (.simp) ASCII file format
- Supports command line file rendering
Render Pipeline Optimizations:
- Backface culling (Discards polygons not facing the camera)
- Frustum culling (Discards polygons outside of view frustum)
- Sutherland–Hodgman Polygon clipping (Removes portions of polygons outside of view frustum)
- n-gon Triangulation (Dividing convex polygons with 4 or more sides into triangles)
- Pixel depth/Z-Culling (Early-out if current point is behind the current raster Z buffer depth)
- Bounding boxes (Increased efficiency during ray intersection tests)