RayForge: C++ Ray Tracing Engine

This project is part of a Computer Graphics class I took under Crane He Chen at Northeastern University, so not all code in this repository is originally mine.

RayForge is a C++14 ray tracing engine that parses custom .ray scene files and renders physically-inspired images with recursive lighting effects.
The project focuses on core rendering systems: geometric intersections, scene-graph composition, multiple light models, material response, reflections/refractions, texture mapping, and acceleration via bounding boxes.

What This Project Does

• Builds full scenes from a directive-based scene description format (#camera, #light_*, #shape_*, #ray_file, #static_affine, etc.).
• Supports multiple primitives and composite geometry:
  • sphere, triangle, cone, cylinder, torus, box
  • scene composition via union, intersection, difference
  • file instancing and affine transforms
• Implements three light types:
  • point lights (distance attenuation)
  • directional lights (parallel, no attenuation)
  • spot lights (distance + angular falloff with cutoff)
• Uses material terms for emissive/ambient/diffuse/specular/transparent response.
• Performs recursive ray tracing with:
  • specular reflection
  • refraction (index of refraction support)
  • cut-off thresholds for recursion control
• Tracks ray tracing performance statistics:
  • total rays
  • primitive intersections
  • bounding-box intersections

Rendering Pipeline

1. Parse .ray scene directives into global scene data (camera, shader, lights) and local geometry/material/texture data.
2. Initialize scene graph nodes and material/texture references.
3. For each pixel, generate a camera ray using perspective projection.
4. Intersect against scene geometry and compute closest valid hit.
5. Shade hit point with light contributions:
   • ambient term
   • diffuse term
   • specular term
   • transparency along shadow rays
6. Recurse for reflected and refracted rays until depth/cutoff limits are reached.
7. Write final RGB output to image.

Implemented Components

The project extends the provided framework by completing core .todo.cpp tasks across:

• camera.todo.cpp: perspective ray generation (getRay)
• triangle.todo.cpp: triangle intersection + barycentric handling + bounds
• pointLight.todo.cpp: ambient/diffuse/specular, shadowing, transparency
• directionalLight.todo.cpp: directional light shading/shadow/transparency
• spotLight.todo.cpp: cone-limited light with angular falloff
• cone.todo.cpp: cone intersection + bounds
• cylinder.todo.cpp: cylinder body/cap intersection + bounds + inside test
• torus.todo.cpp: torus intersection approximation + bounds + inside test
• scene.todo.cpp: reflection, refraction, recursive color evaluation

Build and Run

Requirements

• CMake (3.10+)
• C++14 compiler (clang++/g++)
• OpenGL + GLUT
• JPEG library

Build

cmake -S . -B build
cmake --build build -j

Run

./build/Bin/Assignment2 --in "test.point.ray" --out "output_point.bmp"

Useful flags:

• --width (default: 640)
• --height (default: 480)
• --rLimit (default: 5)
• --cutOff (default: 0.0001)

Scene Inputs and Assets

• Scene files: test.*.ray, creative*.ray, art_submission*.ray, model scenes like dog.ray, dragon.ray, buddha.ray
• Textures/assets: checker.jpg, funtex8.jpg, unsplash*.jpg
• Extended summary source: submission_summary.html

Results Gallery

Lighting and Baseline Validation

Point Light

Directional Light

Spot Light

Primitive and Geometry Validation

Cone

Cylinder

General Test

Creative / Extended Scenes

Creative Scene

Creative Scene 2

Creative Scene 3

Model-Based Scenes

Dog

Dragon

David

Gargoyle Output

Nefertiti Output

Art Submission Renders

Notes

• gargoyle.ray and nefertiti.ray source scene files are excluded from git because they exceed GitHub's 100MB hard file-size limit.
• Their rendered outputs are still included in this repository for visual results.