Path overlay

[anoved]

Don't know if this would be best as part of hmstl or as a separate program. Given a route - a sequence of waypoint coordinates - generate a route model of constant thickness draped over the terrain mesh. The route model should be printable simultaneous with the terrain mesh using a dual extruder printer. The bottom surface of the route mesh should fit flush against the terrain, meaning it should be composed of triangles of the same scale (or, I suppose, smaller faces that lie flush against them).

Route coordinates can reasonably be required to lie within the extent of the height map and be given in terms of the height map pixel coordinates (eg, user must convert geographic coordinates to HM pixels first).

When/how to generate:

• at same time as terrain mesh
• separately, using same input height map and triangulation algorithm
• separately, using terrain mesh stl as input, and "dropping feelers down" from superimposed route to find first intersection with surface?

The right approach may be to generate 2d path at max elevation first (offset to either side of waypoint path for thickness). Matching mesh tris exactly and entirely does not seem feasible if arbitrary direction lines are to be allowed.

[anoved]

Worked out one way to do this using OpenSCAD to handle the CSG operations.