Questions tagged [mesh]
Questions on the use and creation of meshes including the use of MeshRegion, ElementMesh, and TetGenLink.
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Understanding Energy Function
I am trying to implement as rigid as possible mesh interpolation solution provided in this article called "As-Rigid-As-Possible Surface Morphing"
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10....
4
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1answer
59 views
4
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1answer
56 views
Multiple Boundary Conditions for NDSolve in mesh with multiple interfaces
Here is my problem: I want to solve a Laplacian equation in a 2D geometry with multiple interfaces, each interface presenting a different boundary condition.
As for an example, I am working on a ring ...
9
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2answers
98 views
Distinguish between inner and outer boundary in MeshRegion
For example, this is a 2D MeshRegion with one (or more) holes in it:
...
9
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2answers
321 views
Picking mesh elements that are not on the border of the mesh
As an example, let's say I use a set of random points to create a Voronoi mesh
pts = RandomReal[{-1, 1}, {100, 2}];
VoronoiMesh[pts, {-1, 1}]
and get something ...
0
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0answers
36 views
How to get a “smoother” curve for a “discrete”-type curve?
A very interesting problem from here.
I got the algebra in less than a minute with all 6 solutions (integers). But was puzzled a bit that the graph only gives 4. As now I have waken up and tried it ...
2
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1answer
44 views
Information concerning undocumented function “Region`Mesh`MeshNearestCellIndex[r ]”
I'm looking for further information of the undocumented function Region`Mesh`MeshNearestCellIndex[r] (Thanks to Henrik Schumacher!)
The function considers a ...
12
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2answers
161 views
How to Interpolate a 3D MeshRegion?
If you were given some discrete MeshRegion called r (you don't know R):
...
5
votes
1answer
70 views
How to set a NeumannValue on a given ElementMarker on the boundary of a mesh?
How can one apply a NeumannValue on an ElementMarker on the boundary of an ElementMesh for a ...
0
votes
1answer
26 views
DelaunayMesh error : EmptyRegion
What is wrong with the following list of points?
When I apply DelaunayMesh[listPoints] I get the error ...
6
votes
3answers
92 views
Sometimes Region can't build right region
During my work with NDSolveFEM I found strange behavior of function Region.
...
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1answer
51 views
Mapping a boundary value problem: Jacobian in NDSolve and refining mesh close to a point
I would like to solve the (oversimplified!) BVP
$u''(x)-u(x)=0,\qquad x\in[0,\infty)$
with the condition $u(0)=1$. I thought to remap this into the BVP problem
$D[J^{-1}(\xi)u(\xi)]-J(\xi)u(\xi)=0, ...
3
votes
1answer
76 views
How to control boundary markers for overlapping FEM meshes?
I am trying to create FE meshes from vector or bitmap images and have come across the following issue. This is best shown using the following simplified code.
...
4
votes
1answer
132 views
How to create meshes with multiple regions from 2D images?
I would like to import 2D images to Mathematica and to use them to create meshed regions which can then be used for FEM. I create the images in Adobe illustrator so can either import a vector based ...
4
votes
2answers
106 views
How to make a frustum of a cone
For finite element purposes I need a frustum of a cone with a finite wall thickness, i.e. a tapered pipe.
To make a cone is easy
...
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0answers
46 views
How to create surface mesh from a given 2D mesh toplogy?
I would like to convert a very easy(examplary) mesh(2D)
...
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0answers
40 views
Understanding BoundaryMeshRegion error
I am trying to calculate the difference between two Cuboids:
...
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vote
0answers
84 views
ElementMeshContourPlot and PlotLegend [closed]
Does anybody know why ElementMeshContourPlot ignored PlotLegends->Automatic? I have used the useful topic about Von Mises stress but I vould like a colored scale on the right of the plot. With ...
3
votes
1answer
82 views
ImageMesh for continuous 3D images
I have a 3D image containing distance fields, and would like to produce a mesh region from a contour at a fixed level.
I found two options for this
ImageMesh[], ...
4
votes
1answer
105 views
MeshRefinementFunction for region gives error
I would like to refine a mesh within a given path/volume, that is specified by the MeshRefinementFunction option given in ToElementMesh[].
For starting i took a simple 3D MeshRegion of a Tetrahedron
<...
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4answers
344 views
4
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1answer
68 views
Error in Mesh Region during concave hull
I have the following data:
Data.csv
It crates the following image:
Im trying to make a concave hull so that I can create an outline of the region. I have tried to use all versions of the ...
6
votes
2answers
118 views
Inconsistent mesh generation from BoundaryDiscretizeRegion and ToBoundaryMesh at creases
I'm trying to use BoundaryDiscretizeRegion and/or ToBoundaryMesh to generate polygonal models for 3d printing, but I'm having ...
2
votes
1answer
42 views
Difficulty with making the color gradient in the Parametric3D plot
I am making a parametric 3D plot representing a graphical solution of a nonlinear equation. This explains, why the expression is so heavy.
I would like to plot it with the color gradient such as "...
7
votes
2answers
168 views
ToElementMesh ignores Boundaries and MeshRefinemet
I'm building a mesh of a pit storage in Mathematica which I then export to another FEM-software.
I follow the workflow for creating a ElementMesh from the documentation, but it won't work in the way ...
0
votes
1answer
61 views
How to increase the thickness and change colors of the edges in a mesh?
Consider 10 random points as
pts = RandomReal[{-1, 1}, {10, 3}];
The edges of the polyhedron formed by these points can be visualized as
...
7
votes
2answers
122 views
MomentOfInertia for Polyhedra incorrectly computed?
The moment of inertia for Regions seems to be wrongly calculated. Simple example:
...
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0answers
56 views
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1answer
89 views
Mesh does not have a valid dimension as a plotting domain in 11.0
In Version 11.0, it appears that one cannot plot over a mesh. The following code worked in Version 10.2:
...
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vote
0answers
45 views
Options problem for 3D plots
If I'm not mistaken, the code below should produce two identical pictures of a torus. But it does not. The MeshStyle->Thick option seems to be ignored for the first. Obviously the second code ...
4
votes
1answer
174 views
Voronoi mesh from non-parametric surfaces for 3D printing
I am trying to make a Voronoi mesh from the Stanford Bunny surface for 3D printing, intended as a test case to make a Voronoi mesh from any arbitrary, non-parametric 3D surface. Related techniques ...
4
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0answers
76 views
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1answer
136 views
Projecting 3D Mesh Region onto 2D Plane
For vizualization purposes in a beamer presentation I would like to project a 3D MeshRegion like ConvexHullMesh[RandomReal[{-1, 1}, {50, 3}]] onto a 2D plane. How ...
4
votes
1answer
79 views
BooleanRegion with .stl files does not work
Im trying to use BooleanRegion[] on an .stl file.
The imported .stl file is called pores and is of type MeshRegion (...
3
votes
1answer
93 views
Performing queries on mesh structure in a clean way
I have the following problem, which can be stated geometrically as follows:
List all pairs of vertex coordinates in a mesh region of measure 2 (a surface consisting of triangles) where these points ...
8
votes
3answers
177 views
Trouble meshing a Corbino disc
I am trying to simulate current flow using FEM through this particular device (a Corbino disk) and I have difficulties generating the mesh for it. Here is the region:
...
3
votes
0answers
67 views
Finding the shortest distance of two points and an area
So I have a region defined by something like MeshRegion[{{0, 0}, {1, 1}, {2, 1/2}, {2, -1/2}}, {Line[{1, 2}], Line[{2, 3}], Line[{3, 4}], Line[{4, 1}]}], and two ...
10
votes
2answers
165 views
How to return the coordinates of the respective 3 vertexes of a DelaunayMesh's face?
I have a set of points pts1 and a point redPts as below:-
...
14
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3answers
549 views
Crop a Voronoi diagram and get a proper MeshRegion
How can I crop a VoronoiMesh (or any similar MeshRegion) to a non-rectangular region and receive the output as a ...
3
votes
3answers
120 views
Volume of HexahedronElement with non-coplanar faces
I would like to calculate the volume of ElementMesh made of HexahedronElement. Even though ...
4
votes
2answers
155 views
How do I convert a mesh region back into the Graphics3D format?
The Graphics3D format has more styling options than mesh based graphics, so I was wondering if there was a way to convert mesh based objects such as region intersections and unions back into the ...
7
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1answer
153 views
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1answer
71 views
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1answer
66 views
Z-map of a MeshRegion
TL;DR
How can I efficiently compute a matrix representing a z-map of a non-convex MeshRegion?
Longer explanation
I'm developing a collision detection algorithm for a 3-axis NC machine. My idea is ...
1
vote
1answer
53 views
ParametricPlot3D coloring based on whether function located inside/outside of another parametric function
I have two parametric shapes: an inclined ring and an elliptic cone whose vertex lies along the x axis.
...
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vote
1answer
35 views
Find vertices of a hypercube given a set of partitions
Problem
The goal is to take a set of $n$ linear partitions $\left\{p_{k}\right\}_{k=1}^{n}$ and create a hypercubic partition:
$$
\mathbf{P}=p_{1}\times p_{2}\times \cdots\times p_{n}
$$
Each ...
5
votes
1answer
51 views
How to define element size with ToBoundaryMesh?
I am trying to make a mesh for finite element analysis with shell elements: I have to define 2D finite elements in 3D space. My code is:
...
7
votes
3answers
159 views
Visualising Finite Element Mesh in 3D with MeshRefinementFunction
How do you check that a MeshRefinementFunction is doing what you want in a 3D mesh where you only see the boundary mesh?
I started by making a block with a hole as ...
43
votes
2answers
1k views
A geometric multigrid solver for Mathematica?
Cross posted to community.wolfram.com
Mathematica ships a variety of linear solvers through the interface
LinearSolve[A, b, Method -> method]
the most ...
7
votes
1answer
168 views
How can I upload MeshRegions to Mathematica.SE?
I know how to upload images to Mathematica.StackExchange. But what about MeshRegions? That's something I'd like to do frequently. Best would also be a programmatic ...
