Understanding Signed Distance Calculation Between Two Meshes

[Gihong-Yim]

VertScalars scalarVertId = findSignedDistances(meshCompareIn, meshTargetIn);

When applying findSignedDistances(meshCompareIn, meshTargetIn), most of the distance values are negative, but some points have positive values. I think this happens because the criterion for determining whether a point is inside or outside is ambiguous. I would like to understand how the vertices of meshCompareIn are determined to be inside or outside based on the vertices of meshTargetIn.

[Grantim]

Hello!

Inside/Outside classification in findSignedDistance functions is done by this function:

MeshLib/source/MRMesh/MRMesh.h

Lines 252 to 255 in 3f13d6a

	/// computes whether a point (pt) is located outside the object surrounded by this mesh
	/// using pseudonormal at the closest point to in on mesh (proj);
	/// this method works much faster than \ref isOutside but can return wrong sign if the closest point is located on self-intersecting part of the mesh
	[[nodiscard]] MRMESH_API bool isOutsideByProjNorm( const Vector3f & pt, const MeshProjectionResult & proj, const FaceBitSet * region = nullptr ) const;