dijkstra surface path - customize edge weights

[czc98]

Hi!
I found the computeGeodesicPathApprox() function computes dijkstra path, does the edge weight in the code depend on the length of the edge?
If I want to customize the edge weights, is there a way meshlib can do that?
If it can customize the edge weights, it is possible for programmers to make the path pass through the desired area.

[Grantim]

Hello!

geodesic paths always use edgeLengthMetric, but we have these functions for custom shortest edge paths

MeshLib/source/MRMesh/MREdgePaths.h

Lines 86 to 106 in 47a1d71

	/// builds shortest path in given metric from start to finish vertices; if no path can be found then empty path is returned
	[[nodiscard]] MRMESH_API EdgePath buildSmallestMetricPath( const MeshTopology & topology, const EdgeMetric & metric,
	VertId start, VertId finish, float maxPathMetric = FLT_MAX );
	/// finds the smallest metric path from start vertex to finish vertex,
	/// using bidirectional modification of Dijkstra algorithm, constructing the path simultaneously from both start and finish, which is faster for long paths;
	/// if no path can be found then empty path is returned
	[[nodiscard]] MRMESH_API EdgePath buildSmallestMetricPathBiDir( const MeshTopology & topology, const EdgeMetric & metric,
	VertId start, VertId finish, float maxPathMetric = FLT_MAX );
	/// finds the smallest metric path from one of start vertices to one of the finish vertices,
	/// using bidirectional modification of Dijkstra algorithm, constructing the path simultaneously from both starts and finishes, which is faster for long paths;
	/// if no path can be found then empty path is returned
	[[nodiscard]] MRMESH_API EdgePath buildSmallestMetricPathBiDir( const MeshTopology & topology, const EdgeMetric & metric,
	const TerminalVertex * starts, int numStarts,
	const TerminalVertex * finishes, int numFinishes,
	VertId * outPathStart = nullptr, // if the path is found then its start vertex will be written here (even if start vertex is the same as finish vertex and the path is empty)
	VertId * outPathFinish = nullptr, // if the path is found then its finish vertex will be written here (even if start vertex is the same as finish vertex and the path is empty)
	float maxPathMetric = FLT_MAX );
	/// builds shortest path in given metric from start to finish vertices; if no path can be found then empty path is returned
	[[nodiscard]] MRMESH_API EdgePath buildSmallestMetricPath( const MeshTopology& topology, const EdgeMetric& metric,
	VertId start, const VertBitSet& finish, float maxPathMetric = FLT_MAX );

common metrics cam be found here:
https://github.com/MeshInspector/MeshLib/blob/master/source/MRMesh/MREdgeMetric.h

[czc98]

If I calculate a weight for each edge, how do I convert to EdgeMeric?

[czc98]

I already know how to do, thank you