CUDA OBJ Ray Tracer

A simple GPU-accelerated ray tracing renderer for OBJ mesh models, built with CUDA and C++.

This project is centered in the RayTracer folder and loads .obj geometry with optional .mtl materials and textures. It compiles main.cu with nvcc, renders a scene on an NVIDIA GPU, and outputs the final image as image.ppm.

Project Structure

• RayTracer/
  • render_obj.bat - helper script to compile and run the tracer.
  • models/ - mesh assets and materials.
  • src/ - ray tracer source files, including main.cu and supporting headers.

Requirements

• Windows 10 or 11
• NVIDIA GPU with CUDA support
• CUDA Toolkit installed (includes nvcc)
• Microsoft Visual Studio Build Tools or full Visual Studio with C++ workload
• nvcc and the Visual Studio x64 build environment available to the script

Note: render_obj.bat currently calls Visual Studio 2022 Build Tools at: C:\Program Files (x86)\Microsoft Visual Studio\2022\BuildTools\VC\Auxiliary\Build\vcvarsall.bat Update this path if your Visual Studio installation differs.

Setup

1. Open a PowerShell terminal.
2. Change directory to the ray tracer folder:

cd "C:\Users\lukej\OneDrive\Documentos\Senior_Capstone\Capstone\RayTracer"

3. Confirm that nvcc is available and the CUDA Toolkit is installed.
4. Make sure the Visual Studio x64 environment path in render_obj.bat matches your installed toolchain.

How to Run

Recommended: use the helper script

.
render_obj.bat "models\car\" 1920 1080 50 0 0 100

This will:

• compile RayTracer\src\main.cu into main.exe
• run the ray tracer on the first .obj inside models\car\
• create image.ppm in RayTracer\src

Direct invocation

If you prefer to compile manually:

cd "RayTracer\src"
nvcc main.cu -o main.exe
main.exe "..\models\car\Car.obj" 1280 720 25 0 0 80

Command-Line Options

The executable accepts the OBJ path followed by optional rendering and camera parameters.

main.exe <obj_path_or_directory> [width height samples] [azimuth elevation] [radius]

Parameters

• <obj_path_or_directory> - path to a .obj file or a directory containing a .obj
• width - output image width in pixels (default: 480)
• height - output image height in pixels (default: 360)
• samples - samples per pixel for anti-aliasing (default: 1)
• azimuth / elevation - camera rotation angles in degrees (0–360)
• radius - optional camera distance override from the mesh

Examples

Render using a directory containing an OBJ file:

.
render_obj.bat "models\car\"

Render with custom resolution and samples:

.
render_obj.bat "models\car\" 1280 720 32

Render with explicit spherical camera angles:

.
render_obj.bat "models\car\" 1920 1080 50 180 30 130

Output

• Output file: RayTracer\src\image.ppm
• Format: plain PPM (P3)

Notes

• Rendering high resolutions or many samples can be slow.
• If the script fails to locate vcvarsall.bat, update the path in render_obj.bat.
• If render_obj.bat cannot find a .obj, ensure the provided input path exists and contains at least one .obj file.

Troubleshooting

• nvcc not found: verify CUDA Toolkit installation and add it to your PATH.
• vcvarsall.bat path invalid: update the hard-coded Visual Studio path in render_obj.bat.
• No output image: confirm the program completed successfully and that image.ppm was saved in RayTracer\src.

Math-402 Capstone: The Rendering Equation and Monte Carlo Integration

• For those interested, in Math_Capstone\ you can find my math capstone research of the rendering equation and Monte Carlo integration
• There you can find the PDF of my final paper Capstone_paper.pdf, as well as the latex source code in Math_Capstone/src