Contributing Code

Developing code for BRL-CAD becomes easier when you understand how to obtain and modify the code.

1. Obtaining the Code

You can get the development code for BRL-CAD from our Git code repository using the following command:

git clone

The code will be saved in your /home directory, and you can compile it by following the instructions in the HACKING file located in top-level code directory. That said, the following are a few useful tips to help get you going.

1.1. Obtaining the Development Tools

BRL-CAD uses the CMake build system and will compile with most compilers. Download CMake and install it. If necessary, compile it from the source code.

1.2. Configuring the Environment

Next, set up the build directory and configure the compilation. At compilation time, BRL-CAD considers most warnings to be errors, so it’s best if you lower the level of error logging to debug. To do that, run the following command:

cmake ../brlcad_build -DBRLCAD_BUILD_TYPE=Debug

1.3. Compiling BRL-CAD

It will take anywhere from a few minutes to one hour to compile BRL-CAD, depending on your hardware. Run the following command to compile the software:


If the build fails, run make again and capture the output to a log file (so you can report it and/or get help) by running the following command:

make > build.log 2>&1

If you have a multiple cores, you can request parallel compilation with the -j option, e.g., make -j4 on a 4-core system.

1.4. Installing BRL-CAD

Depending on the version of the source code that you started with, BRL-CAD should install into the following folder:


Where SUBDIR is either rel-VERSION or dev-VERSION.

1.5. Performing a Quick Test

You don’t have to install BRL-CAD. Instead, you can just run the binaries that are found in the brlcad_build/bin directory by running the following commands:

bin/benchmark; bin/mged;

That’s it! If you have a Release compile, you can submit your benchmark results to

2. Discussing Code

After obtaining the source code, you should to join the BRL-CAD developer mailing list and the #brlcad IRC channel at

Joining both lists helps introduce yourself to the BRL-CAD community and gives you the opportunity to regularly communicate with other experienced contributors. You can also ask questions on the mailing list or the IRC channel.

Note that BRL-CAD contributors have a set of rules that they try to respect and follow to enable collaboration and communication. We strongly encourage new contributors to be creative and to be specific when asking questions on the mailing list or on the IRC channel. We also strongly advise you to use interleaved posting when replying on any communication channels. And never be afraid to ask questions.

Finally, when modifying code, it’s advisable to regularly consult with experienced developers and to follow these rules of thumb when adding changes:

  • Test your code to ensure that the change is correct.

  • Document your changes clearly and succinctly to ensure that others understand the change.

  • Write tests for your change so others can use them when testing subsequent changes.

  • Make a handful of patches and submit them to GitHub for review.

  • Obtain commit access.