Assignment 0. Devops
Table of Contents
- 1 Fork our repo, and clone it and all the libraries
- 2 Build the libraries and the demo app
- 3 Send us a screenshot
See the schedule for due date info.
This assignment is just about building the C++ development environment you’ll use in the coming assignments to build your ray tracing and rasterization pipelines. For this class we are providing a collection of libraries; some are standard external libraries, some are built just for this course to make the specific goals of the assignments easier to achieve with less code.
The external libraries include:
- Embree, Intel’s collection of high performance ray tracing kernels. It provides a quite simple interface that makes it easy to get started, and also provides the parallel and streaming kernels needed to get to higher performance.
- Assimp (stands for “asset importer”), a popular open-source library for reading scenes. It supports lots of scene formats and puts the mesh and hierarchy data into a simple lowest-common-denominator structure that it’s easy to read it from.
- Nanogui, a minimal user interface framework on top of OpenGL. It provides cross-platform UI with no need for any help from the native window system.
- STB, a header-only library providing very simple versions of common graphics needs such as image i/o.
- cpplocate, to simplify finding our assets.
- GLM, a vector math library that uses conventions identical to GLSL.
The libraries we are providing for this course include:
- GLWrap, which provides some simple wrappers around OpenGL objects to support writing OpenGL code in a reasonable C++ style.
- RTUtil, which provides a number of functions for input parsing, geometric computations, reflectance models, and random sampling, as well as ImgGUI, a simple app built on GLWrap and Nanogui that provides the ability to display an image in a window.
The goal for this first week is to get your development environment set up and the libraries all compiled. To get set up follow the steps below, ending with a handin. Please don’t hesitate to reach out for help; C++ development is tricky and if you don’t have much experience it’s likely you will run into one problem or another.
1 Fork our repo, and clone it and all the libraries
First go to our repository at https://github.coecis.cornell.edu/cs5625/Starter22 and make a fork using the GitHub web UI. Your fork should be a private repository. This will let you easily pull updates related to bug fixes and later assignments from our repository into yours. Then clone your repository with:
git clone --recursive https://github.coecis.cornell.edu/<path to your repo>.git
(where you fill in the actual URL for your repository). This gets you
the contents of our repository and also the git submodules that bring in
the various libraries we depend on. If you forget
--recursive (I always do), it’s OK; you can always get the
submodules into the right state by running:
git submodule update --init --recursive
Once the submodules are there, you will see lots of files under
There is one library that’s tricky to build from source, Intel’s TBB (used by Embree), so you’ll want to install it separately (see platform-specific hints below). The Embree API documentation and this guide have more details about TBB.
The starter code is set up to use the CMake build system, which you can install with its own installer or as suggested below.
1.1 Hints for MacOS users
On the Mac the easiest way to get the tools you need is from one of the open-source package managers:
Make sure you’re installing the version of TBB appropriate for your system’s architecture – for example, if you are on an M1 Mac do not install the x86 version of TBB. This will happen if you’re running Homebrew through Rosetta.
By default CMake may try to build for an old OS version that is not
supported by the libraries, so we recommend setting a particular minimum
(substitute the version of your OS if it is older than 12.0).
If your Mac has an Apple CPU (M1, etc.) you will need to mention this
to CMake by giving it the option
-DCMAKE_OSX_ARCHITECTURES=arm64 (on an Intel mac just omit
So where we write just
cmake .. below, you will write
cmake -DCMAKE_OSX_ARCHITECTURES=arm64 -DCMAKE_OSX_DEPLOYMENT_TARGET=12.0 ..
You can use Xcode (Apple’s native IDE) instead of Make if you prefer,
by asking CMake to generate Xcode project files using the option
1.2 Hints for Windows users
You can install CMake with its installer. CMake can work with the
make utility or with Visual Studio. Most students who
use Windows choose Visual Studio.
To use Visual Studio, ask CMake to generate Visual Studio project
files using the option
-G "Visual Studio 17 2022"
(substitute your version if needed;
cmake -G by itself
provides a list of available generators).
To install TBB on Windows there is an installer
or you can download it from here.
You may find that you also need to set the
environment variable to the location of your download if you use the
1.3 Hints for Linux users
On Linux, you’re going to need your distribution’s core development
build-essential on Ubuntu and
base-devel on Arch) which you can install using your
system’s package manager.
You will also need the TBB development libraries –
libbtbb-dev on Ubuntu or
tbb on Arch. If you
get a warning about using an outdated version of TBB, that is okay to
Additionally, you might need packages required for developing an
application that creates windows. This will be
Ubuntu. For other distros, you can see the GLFW info
page about which packages might be required, though their absence is
typically pretty easy to diagnose.
2 Build the libraries and the demo app
To build the demo app, follow this sequence, starting from the root directory of your working copy of our repository:
mkdir build # With CMake you always want to build in a separate directory. cd build cmake .. # This tells CMake to look for its configuration in the parent directory. make -j 5 # CMake just sets up files for Make; this asks Make to actually build the software.
This will take a few minutes. The
-j <n> option
tells Make how many parallel tasks to run; conventional wisdom says that
for the fast builds you should make this the number of CPU cores on your
system + 1. Once you’ve compiled once and are just compiling code
changes as you develop, you might want to omit this option to build with
1 thread, so that the
make output is more sequential and
thus more legible.
At the end, if all goes well, you will have an executable called Demo in the build directory. Run it:
and you should get a colorful window.
If you have problems at this phase they are likely related to compiler setup, development environment, or other things, and you will want to reach out for some help!
3 Send us a screenshot
Finally, take a screen shot of the demo app and hand it in on CMS. The point value of this week’s assignment is very small; the goal is to get you set up while there is still time to get help with build environment issues.