When generating 3D meshes from 2D contours (especially bitmap-derived), applying Douglas-Peucker simplification via shapely's LineString.simplify() removes collinear points that would create degenerate triangles. Use tolerance around 0.5-0.7 pixels for typical bitmap resolutions, and always set preserve_topology=True to maintain valid geometry structure.
The simplified contour should then be converted to a Polygon, optionally cleaned with buffer(0), and extruded into a mesh. This pattern is essential for creating watertight meshes suitable for 3D printing, as degenerate triangles break manifold properties. The tolerance parameter controls the trade-off between geometric fidelity and mesh quality - higher values produce smoother but less detailed shapes.
