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Questions tagged [tetrahedra]

35 questions
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3 answers

tetrahedrizing a mesh

I am looking for an algorithm that receives a 3d surface mesh (i.e comprised of 3d triangles that are a discretization of some manifold) and generates tetrahedra inside the mesh's volume. i.e, I want the 3d equivalent to this 2d problem: given a…
olamundo
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Building the tetrahedra of a set of random points - tetrahedralization

I have a set of points (1 million of them, possibly more in the future, like 10 or 100 million) in 3D space that forms a sphere (they fill the sphere - they're not just on the surface) and I would like to build the tetrahedra that connect each…
user22744
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How to check whether the point is in the tetrahedron or not?

I know all coordinates of tetrahedron and the point I would like to determine. So does anyone know how to do it? I've tried to determine the point's belonging to each triangle of tetrahedron, and if it's true to all triangles then the point is in…
Denis Lolik
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How to draw a Tetrahedron mesh by matplotlib?

I want to plot a tetrahedron mesh by matplotlib, and the following are a simple tetrahedron mesh: xyz = np.array([ [-1,-1,-1], [ 1,-1,-1], [ 1, 1,-1], [-1, 1,-1], [-1,-1, 1], [ 1,-1, 1], [ 1, 1, 1], [-1, 1, 1]],…
Huayi Wei
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Barycentric coordinates of a tetrahedron

I would like to ask for help regarding barycentric coordinates of a tetrahedron: Following an approach I found here: http://www.cdsimpson.net/2014/10/barycentric-coordinates.html i implemented a C++ function for finding barycentric coordinates of a…
christianlehmann
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Given a point and a large number of tetrahedrons, how to efficiently determine in which tetrahedron the point is

Suppose we define a point to be a tuple of three floating-point numbers, and a tetrahedron a tuple of four points. Suppose we have a tetrahedron and a point, we can determine whether the point belongs to the tetrahedron following the solutions…
zell
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Large, mostly empty data structure for tetrahedron faces

I'm trying to link the node id of every face in a tetrahedron with it's corresponding tetra id. tetras = [1 2 3 4 % Tetra 1 5 6 7 8] % Tetra 2 For tetra 1, there are four faces: faces = [1 2 3; 1 2 4; 1 3 4; 2 3 4] % Notice these are…
Alex L
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Faster tetrahedron-tetrahedron intersection

For one project of mine I require reliable detection of intersection between two tetrahedrons in 3D space. I do not need the points/lines/faces just to know if intersection is present or not. Touching is considered intersection too but common…
Spektre
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Volume of two intersecting tetrahedra in CGAL

I am looking for a fast way to compute the volume of the intersection of two tetrahedra using CGAL. If I read and understood the CGAL manual correctly I could create the two tetrahedra as 3D Nef Polyhedra, then compute their intersection as 3D Nef…
Fab
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Creating first triangle in DeWall Algorithm (Delaunay Triangulation)

I am trying to understand a particular approach of the DeWall algorithm to perform a 2D/3D delaunay triangulation/tetrahedralization (DT). I am especially interested in the 3D case. Where other divide and conquer algorithms create partial DT and…
christianl
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tetgen library- tetrahedralize without convex hull

I am trying to tetrahedralize my mesh using tetgen library. However it creates convexhull on the mesh like in the picture. How can I tetrahedralize my mesh while preserving boundary surface of the mesh using tetgen library?
user3117189
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How do I avoid LNK2005 and LNK1169 errors while compiling TetGen in my project?

I am trying to compile TetGen and use the code below to tetrahedralize a .ply file although I am getting these two linker errors: LNK2005 main already defined in tetgen.obj LNK1169 one or more multiply defined symbols found The files that are…
Mineohmight
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CGAL::Polyhedron_3 makes unwanted duplicated vertices using make_tetrahedron(), how to solve it?

I was trying to create a volume mesh using the CGAL::Polyhedron_3 data structure when, doing some tests, I noticed that the make_tetrahedron function duplicates the vertices already present in the polyhedron. Example: Two tetrahedra that share a…
Davide
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How to determine the normal of the triangles faces of tetrahedral?

Tetrahedral is given by the points: p0 = (2, −1,0), p1 = (2,1,0), p2 = (−1,1,0), p3 = (1,0,4) How can I determine the unit normal (facing outside) of the triangles faces of the tetrahedral? And how can I calculate the implicit equation of the planes…
ron
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CGAL 3D Mesh: how to ensure there are always at least two elements between the opposite sides of the domain?

I am using the CGAL package 3D Mesh generation to convert a triangulated model of a turbine blade into a tetrahedral mesh. However, my downstream application requires at least two tetrahedra between the opposite sides of the domain. Unless I set…
Dominik Mokriš
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