GMAN
GMAN reads RenderMan Interface Bytestream (RIB) scene files and writes images. RenderMan is Pixar's published interface specification; GMAN is a clean-room implementation of it. RenderMan is a registered trademark of Pixar; GMAN is not associated with or endorsed by Pixar.
History
GMAN started in 1999, was shelved in 2002, and came back in 2026 on a CMake / C++23 build. The repository is public, licensed LGPL-2.1-or-later.
Build and install
Needs CMake 3.25 or newer, a C++23 compiler (clang 16+ or gcc 13+), libtiff, libpng and zlib. POSIX only: macOS and Linux. A VS Code devcontainer is included.
git clone https://github.com/jac18281828/gman.git
cd gman
cmake --preset dev
cmake --build build --parallel
Render your first scene
A RIB file is plain text. Save this as sphere.rib:
Display "sphere.tif" "file" "rgba"
Format 640 480 1
Projection "perspective" "fov" [45]
Translate 0 0 5
WorldBegin
Sphere 1 -1 1 360
WorldEnd
Then render it:
./build/gman sphere.rib
sphere.tif lands next to it.