CMS on a Uniform Grid

A Python visualisation of the Cubical Marching Squares (CMS) isosurface-extraction algorithm running on a uniform voxel grid.

What it does

1. Evaluates a signed-distance field (SDF) on a regular 3-D grid.
2. Runs Marching Squares independently on each cell face to find isosurface contour segments and Hermite data.
3. Connects per-face feature points into closed 3-D loops (the mesh edges).
4. Displays the result interactively with matplotlib (drag to rotate, scroll to zoom).

Visual legend

Symbol	Meaning
Blue filled circles	Inside corners (SDF < 0)
Orange open circles	Outside corners (SDF ≥ 0)
Green arrows	Surface normals near the isosurface
Grey wireframe	Cell grid

Requirements

• Python 3.10+
• numpy
• matplotlib

pip install numpy matplotlib

Usage

python cms_uniform_grid.py [--sdf <shape>]

--sdf choices: box (default), sphere, torus, combo, smooth_union

python cms_uniform_grid.py --sdf torus