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BlenderGIS Delaunay 2.5D – How to enforce breaklines?

Open FraJoMen opened this issue 1 year ago • 1 comments

Hi BlenderGIS developers,

I’ve been exploring BlenderGIS’ built-in Delaunay 2.5D triangulation feature, and I really appreciate how it generates a triangulated surface from a point cloud. However, I’m currently struggling with adding breaklines (discontinuity constraints) to the triangulation.

Here’s my workflow so far: ✅ Step 1: Importing a 3D shapefile with points and discontinuity lines into Blender using BlenderGIS. ✅ Step 2: Running the Delaunay triangulation from BlenderGIS, which correctly triangulates the imported points. ❌ Problem: The imported discontinuity lines are not being used as constraints in the triangulation.

My questions:

Does BlenderGIS' Delaunay support constrained triangulation (i.e., enforcing imported breaklines as edges)? If not, is there a recommended way to introduce these constraints manually? I noticed that BlenderGIS calls delaunay_2d_cdt() from mathutils.geometry. Does this function already support constraints, or does BlenderGIS handle them separately? Initially, I considered using Triangle, but I’d love to see if BlenderGIS already provides a solution before relying on external libraries.

Thanks a lot for your help!

FraJoMen avatar Mar 10 '25 11:03 FraJoMen