RTXplay

A lab for playing around with NVIDIA's realtime raytracing concept. The lab intends to migrate Pete Shirley's raytracer presented in his book series Raytracing in one weekend (RTOW) to become Raytracing with OptiX (RTWO) which utilizes the new RT cores introduced by NVIDIA with Turing microarchitecture.

Code in the top-level folder was created while working through the first book of Pete's series. Creation followed the suggested method of typing yourself and foregoing copy and paste. Doing so there have been few changes to the code logic. Most changes concerned with style guide and naming.

The optx folder contains RTWO. Work started out with the optixTriangle sample from the OptiX SDK which has been modified step by step as shown by the repository's commit history.

First aim was a 1:1 port of RTOW to OptiX to get RTWO. Result is in manastra branch. After that, work proceeded with arbitrarily picked objectives to explore various OptiX features. See commit history of main branch for details.

Build

Due to lack of appropriate hardware development and tests had been split on Windows and Linux respectively.

Windows (Development)

• Install Cygwin 3.1[^1] with development tools (GCC, make etc.)
• Install Visual Studio 2017 Community
• Install CUDA 11.4 (omit driver if lacking a GPU)
• Install Optix 7.3 SDK
• Add nvcc.exe and cl.exe to PATH
• Install ImageMagick 7 (Windows installer)
• Run make in top-level directory of repo to get RTOW
• Run make in optx directory to check compilation (no linking) of RTWO

[^1]: NVCC may fail with newer versions.

Linux

• Get appropriate hardware, e.g. AWS EC2 instance type g4dn.xlarge with Amazon Linux 2 AMI

  # on first start
  sudo yum update -y
  sudo reboot

• Install CUDA Toolkit 11

  # prerequisites
  sudo yum group install "Development Tools"
  
  wget https://developer.download.nvidia.com/compute/cuda/11.4.0/local_installers/cuda_11.4.0_470.42.01_linux.run
  sudo sh cuda_11.4.0_470.42.01_linux.run
  
  # environment (~/.bashrc)
  export PATH=/usr/local/cuda/bin:$PATH
  export LD_LIBRARY_PATH=/usr/local/cuda/lib64:$LD_LIBRARY_PATH
  
  # check driver
  nvidia-smi
  
  # check toolkit
  cd NVIDIA_CUDA-11.4_Samples/1_Utilities/deviceQuery
  make ; ../../bin/x86_64/linux/release/deviceQuery ; cd

• Install OptiX 7 SDK

  # prerequisite
  sudo yum install -y cmake3 freeglut-devel libXcursor-devel libXinerama-devel libXrandr-devel
  
  sudo mkdir /usr/local/optix-7.3
  sudo ln -s /usr/local/optix-7.3 /usr/local/optix
  sudo sh NVIDIA-OptiX-SDK-7.3.0-linux64-x86_64.sh --prefix=/usr/local/optix-7.3 --exclude-subdir
  
  # environment (~/.bashrc)
  export LD_LIBRARY_PATH=~/optix-samples/lib:$LD_LIBRARY_PATH
  
  # check
  mkdir optix-samples ; cd optix-samples
  cmake3 /usr/local/optix/SDK ; make ; cd

• Install ImageMagick 7

  # prerequisites
  sudo yum install libpng-devel
  
  git clone https://github.com/ImageMagick/ImageMagick.git
  cd ImageMagick
  ./configure --disable-opencl ; make -j $(nproc) ; sudo make install

• Run make in optx directory of repo

Gallery

RTWO (Raytracing with OptiX) samples
1 spp (samples per pixel) in 189 milliseconds	50 spp in 776 milliseconds
500 spp (default) in 5586 milliseconds	no defocus blur

RTWO samples with experimental	triangle hit correction	made with branch hitcorr
enabled for diffuse only	reflect added	refract added

Sphere (subdivided tetrahedron)	samples made with commit
single triangle, no subdivision	1 subdivision	2 subdivisions
3 subdivisions	4 subdivisions	5 subdivisions
6 subdivisions	sphere (6 subdivisions)	triangled bounding box