Amino is library of basic utilities for robotics software. It covers mathematical and linear algebra routines, memory management, time-handling, and various utilities.

• Menagerie of Representations:
  • Rotation and Transformation Matrices
  • Ordinary Quaternions
  • Dual Quaternions
  • Quaternion-Vector
  • Axis-Angle / Rotation-Vector / Log-map
  • Euler Angles
• Derivatives and Exact Integration
• Numerically stable log and exponential

• Container for LIFO-ordered memory allocation
• O(1) allocation and deallocation

• Lightweight LAPACK wrapper: Handles work-array creation for LAPACK using memory regions
• Multiple Runge-Kutta integrators, including adaptive integrators

• Import robot geometry from URDF and Collada
• Generate POV-ray scene files for animation frames
• Distribute POV-ray rendering over multiple machines

./configure && make && make install

See the INSTALL file and ./configure --help for details and dependencies.

Ray tracing is computationally expensive. Here are a few notes to help performance.

Ray tracing is embarassingly parallel, both across multiple frames and across pixels within a frame. The easiest way to render faster is to throw more cores at the problem.

While POV-Ray can use multiple threads to render a frame, parsing the input file uses only a single core. If large meshes are used, this can take a noticeable amount of time, and must be repeated for each frame. Consequently, rather than using multiple threads per frame, it may often be better to render multiple frames in parallel so that parsing is parallelized across the different frames.

Ray tracing is floating-point heavy. A few compilation flags make a small but noticable (~10%) improvement in performance.

• -march=native: optimize for the current CPU. This may take advantage of FPU instructions available on newer CPUs, e.g., AVX.
• -ffast-math: optimize floating-point computation in ways that my violate IEEE semantics. Note that this could flag may slightly change the resulting image.
• -flto: enable link-time optimization. This optimizes across multiple translation units.

• Why dual quaternions?

  • Dual quaternions are more compact and easier, computationally, to normalize and filter than matrices.

• How can I load a URDF file?

  • Use the scene graph compiler, aarxc, to generate code from the URDF file. Note that URDF support has additional dependencies; see ./INSTALL for details.

• How can I reload a modified scene graph file without restarting my program?

  • Compile the scene graph to a shared library and load the library with dlopen(). To reload the scene graph, recompile the scene graph and dlopen() the library again.

• I get error messages about missing .obj files or Blender being unable to convert a .dae to Wavefront OBJ.

  • We use Blender to convert various mesh formats to Wavefront OBJ, then import the OBJ file. The Blender binaries in the Debian and Ubuntu repositories (as of Jessie and Trusty) are not built with COLLADA (.dae) support. You can download the prebuilt binaries from http://www.blender.org/ which do support COLLADA.

• When I try to compile a URDF file, I receive the error "aarx.core: not found".

  • URDF support in amino is only built if the necessary dependencies are installed. Please ensure that you have SBCL, Quicklisp, and Sycamore installed and rebuild amino if necessary. See ./INSTALL for details.

• When building aarx.core, I get an enormous stack trace, starting with: 'Unable to load any of the alternatives: ("libamino_planning.so" (:DEFAULT "libamino_planning"))'.

  • This means that SBCL is unable to load the planning library or one of its dependecies, such as OMPL. Typically, this means your linker is not configured properly. The easiest fix is to set the LD_LIBRARY_PATH variable. First, find the location of libompl.so, e.g., by calling locate libompl.so. Then, add the directory to your LD_LIBRARY_PATH variable. Most commonly, this will mean adding one of the following lines to your shell startup files (e.g., .bashrc):

    export LD_LIBRARY_PATH="/usr/local/lib/:$LD_LIBRARY_PATH"

    export LD_LIBRARY_PATH="/usr/local/lib/x86_64-linux-gnu/:$LD_LIBRARY_PATH"