This project implements a ray tracing assignment with an extensible acceleration layer:

• Loads geometry from Wavefront OBJ (v, vt, f) and MTL (Kd, Ks, Ns, d/Tr, map_Kd)
• Supports texture sampling with generated mip levels and trilinear filtering
• Supports two acceleration backends:
  • Embree backend
  • Custom backend (currently baseline traversal, prepared for KD-tree evolution)
• Includes OpenGL scene viewer with fly camera controls
• Uses GLM for camera/vector math
• Writes output as JPG via stb_image_write

On Arch Linux:

sudo pacman -S embree glm stb cmake
cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build -j

On Ubuntu/Debian-like systems:

sudo apt install libembree-dev libglm-dev libstb-dev cmake
cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build -j

This creates executable build/raytracer (compile-time Embree backend).

Raytracing loops are parallelized with OpenMP. You can control thread count with:

OMP_NUM_THREADS=8 ./build/raytracer ...

To build both backend-specific binaries:

cmake --build build --target backends -j

This creates:

• build/raytracer-embree
• build/raytracer-kdtree

Build OpenGL viewer target:

cmake --build build --target raytracer-viewer -j

This creates:

• build/raytracer-viewer

Build interactive raytraced viewer target:

cmake --build build --target raytracer-rtviewer -j

This creates:

• build/raytracer-rtviewer

The interactive raytraced viewer also uses OpenMP for per-frame pixel traversal.

Run automated Embree vs KD benchmark cases:

cmake --build build --target benchmark -j

This generates:

• renders in renders/bench/
• CSV metrics in report/benchmark_results.csv

CSV columns:

• scene path
• backend
• resolution
• build/trace times
• total/shadow ray counts
• rays/s metrics

./build/raytracer <input.obj> <output.jpg> [options]
./build/raytracer <input.obj> -o <output.jpg> [options]

Assignment-style options:

• -vp <x y z> camera position
• -vd <x y z> camera viewing direction
• -up <x y z> camera up vector
• -fovy <deg> vertical field of view in degrees
• -ltcol <r g b> current light color
• -ltpos <x y z> add point light (uses last -ltcol)
• -r <n> recursion depth (0 primary only, 1 adds shadow rays, >=2 adds reflections)
• -normals <default|invert|auto> normal orientation mode (auto tries to detect inward-facing winding)
• -res <width height> output resolution
• -o <path> output image path
• -accel embree|kdtree runtime backend switch (only in non-forced builds)

Legacy aliases (still available):

• --width, --height, --fov, --eye, --target, --up, --lightdir, --background

The eye/target/up/fov parameters map directly to an OpenGL-style camera setup.

./build/raytracer scenes/single_triangle.obj -o out_triangle.jpg \
  -vp 0.0 1.0 3.0 -vd 0.0 -0.2 -1.0 -up 0 1 0 \
  -fovy 55 -ltcol 1 1 1 -ltpos 4 6 2 -r 2 -res 1280 720

./build/raytracer scenes/pyramid_room.obj out_room.jpg \
  -vp 2.8 1.7 3.2 -vd -2.8 -0.9 -3.2 -up 0 1 0 \
  -fovy 52 -ltcol 1 1 1 -ltpos 5 7 2 -r 2 -res 1600 900

Generate all bundled scene renders:

cmake --build build --target render-all -j

Generate a single scene render:

cmake --build build --target render-single-triangle -j

cmake --build build --target render-pyramid-room -j

Outputs are written to renders/.

The program prints required stats at the end:

• acceleration structure build time
• ray tracing time
• total computed rays
• number of shadow rays
• throughput in rays/second (with and without build time)

To download additional internet scenes for experiments:

cmake --build build --target fetch-scenes

Downloaded files are placed in scenes/external/. Track attribution and license notes in scenes/external/SOURCES.md before submission.

Run:

./build/raytracer-viewer scenes/pyramid_room.obj

Controls:

• W/S: forward/backward
• A/D: strafe left/right
• Q/E: down/up
• Shift: speed boost
• hold right mouse button and move mouse: look around
• P: print camera as -vp/-vd/-up arguments for offline raytracing
• Esc: quit

Run:

./build/raytracer-rtviewer scenes/external/spider.obj \
  -vp -19.01 23.4072 109.266 -vd 0.0207327 -0.29089 -0.956532 -up 0 1 0 \
  -res 640 360 -r 1 -normals auto

Controls:

• W/S: forward/backward
• A/D: strafe left/right
• Q/E: down/up
• Shift: speed boost
• hold right mouse button and move mouse: look around
• P: print camera as -vp/-vd/-up arguments
• Esc: quit

• src/main.cpp thin executable entrypoint
• src/raytracer_app.cpp render orchestration and tracing loop
• src/raytracer_app.hpp public entrypoint declaration for raytracer module
• src/raytracer_types.hpp shared domain types (scene/material/ray/camera/stats)
• src/raytracer_io.hpp / src/raytracer_io.cpp CLI and OBJ/MTL loading
• src/raytracer_accel.hpp / src/raytracer_accel.cpp acceleration backends (Embree + custom KD-tree)
• src/raytracer_texture.cpp texture loading and mipmap generation
• src/viewer.cpp OpenGL viewer application
• scenes/*.obj example scenes
• CMakeLists.txt build configuration