Path Tracer

This work is in progress.

CUDA / C++ path tracer with bounding volume hierarchy (BVH) based on the tutorial series by jbikker

Pure C++ version for CPU

Test scenes

Scene 0: 3 instances	BVH heat map (max 267)

Scene 1: 10,000 instances	BVH heat map (max 600)

Scene 2: Model with vertex attributes	BVH heat map (max 123)

	triangles per mesh	BLAS	time (s)	TLAS	total triangles	max tests
Scene 0	505,848	792,591	0.88	5	1,517,544	267
Scene 1	505,848	792,591	0.88	19,819	5,058,480,000	600
Scene 2	3,828	4,899	0.0049	1	3,828	123

Performance

• Resolution: 1500 x 800
• Samples: 100
• Max bounces: 6
• CPU: 13th Gen Intel Core i7-13700H × 20
• GPU: NVIDIA GeForce RTX 3050 6GB

"Bust of Menelaus" by Scan The World

"Viking room" by nigelgoh (edited)

Environment map from HDR Haven

Features

• BVH (BLAS + TLAS) construction and traversal
• Cook-Torrance
• Trowbridge-Reitz (GGX) specular
• Lambertian diffuse
• BRDF importance sampling

Use

Running outputs parameters and progress to the console

Resulting image is output as output.bmp

• make clean (to remove old executable)
• make build
• make run (with default settings)
• make all (clean, build, run)
• ./PathTracer [options]
  • -d 0: CUDA (default), 1: CPU
  • -w width of rendered image (e.g. -w 512)
  • -h height of rendered image
  • -s samples per pixel
  • -b maximum bounces per ray per sample
  • -t number of threads (ignored when using CUDA)
  • -p preset scene [0, 2]
  • -a output BVH heatmap (ignores -s and -b)

Dependencies

• GLM for maths functions and data structures
• stb for reading and writing images (included in /lib)
• stl_reader for reading STL files (included in /lib)
• tinyobjloader for loading OBJ files (included in /lib)
• C++17
• make (optional)