This Rep contains some C++ experiments from our Ray Tracing Harmonic Functions paper. It was mostly used to debug code that I wrote for our Blender implementation, but may be useful on its own. But be warned: this code is messy research code hacked together while running experiments on a deadline. So feel free to reach out if you have problems using it.

On mac/linux, you can set up this project with the following commands.

git clone --recursive https://github.com/MarkGillespie/harnack-polyscope.git
cd harnack-polyscope
mkdir build
cd build
cmake -DCMAKE_BUILD_TYPE=RelWithDebInfo ..
make -j7
bin/run

Running the program with no arguments will load up a collection of simple nonplanar polygons used in our experiments. You can also pass in an obj file to load its faces as (possibly-nonplanar) polygons, or pass in a polygon specified as a *.loops file, where each line lists out the xyz coordinates of each vertex in a loop, e.g.:

v1.x v1.y v1.z v2.x v2.y v2.z .... vk.x vk.y vk.z

By default, only the first face of an obj file or first loop in a *.loops file is intersected by Harnack tracing queries. You can adjust which face/loop is considered via Parameters > loop_id.

The number of rays which are shot can be modified through Parameters > resolution x and Parameters > resolution y.

In the UI there is a button to attempt to mesh the 2π solid angle level set of the input loops (Sphere Tracing > Build Sphere Tracing Mesh), but this function uses a lot of questionable heuristics, and was only ever used on very simple polygons. If you pass it a complicated input, it will probably produce garbage.