Simple 3D Computational Geometry

SCG is a simple, value oriented, MIT License library for 3D computational geometry in C++11.

Examples

Finding the angle between two vectors

point p(1, 1, 0);
point q(-1, -1, 0);
double a = angle_between(p, q);
assert(within_eps(a, 180, 0.00001));

Finding a rotation from one vector onto another

point from(1, 0, 0);
point to(0, 0, 1);

const rotation r = rotate_from_to(from, to);

cout << apply(r, from) << endl;

Loading a mesh from an STL file

auto triangles = parse_stl("./test/stl-files/SlicedCone.stl").triangles;
triangular_mesh m = make_mesh(triangles, 0.001);
cout << "# of triangles = " << m.triangle_list().size() << endl;

Build Instructions

After cloning the repo cd into the top directory of the project. Then do:

cmake .
make -j

This will build several things.

• libutils.a: A utility library used by the main geometry library
• libgeometry.a: The geometry library itself.
• geometry-tests: The unit tests for this library
• run-examples: An executable that contains some samples of how to use this library

To run the tests do:

./geometry-tests 

To run the examples do:

./run-examples

Data Structures

• 3D points
• Planes
• Triangles
• Boxes
• Triangular meshes (stored using a halfedge data structure)
• Rotations and homogeneous transformations
• Height fields
• Voxel volumes

SCG also has a built in binary STL file parser to load data in to triangular meshes.

Dependecies

• boost