find which tetrahedral element a point belongs to

Question

I have a tetrahedral mesh of a 3d region. The mesh is defined by two files with extensions .node and .ele which contain data related to nodes and elements (this is the format of

Answer 1

If you know the orientation of the faces of your tetrahedra, then you only need to compute the volume of tetrahedra formed by your point p=(x1,y1,z1) and each face of the tetrahedra. Point p is inside a tetrahedron if and only if it makes a positive volume with respect to each face.

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^{Snippet from Computational Geometry in C.}

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