Questions tagged [mesh]
Questions on the use and creation of meshes including the use of MeshRegion, ElementMesh, and TetGenLink.
583
questions
1
vote
1answer
32 views
2
votes
1answer
79 views
Neumann boundary condition ignored
Im trying to solve a system of two PDE (im[t,x] and ia[t,x]) that are dependent on time and distance. I’m using my own anisotropic mesh (thanks to @TimLaska) that is aimed to represent an interface ...
2
votes
0answers
58 views
How to reduce the number of triangles in a mesh? [duplicate]
I am trying to turn a Graphics3D object (the Stanford Bunny) into a mesh. The result from using DiscretizeGraphics has too many ...
5
votes
1answer
180 views
Create a voxelized mesh from an STL mesh file
I would like to create a cubic or 3d grid mesh with a constant size for a surface mesh that represents a hollow torus saved in an STL file. mesh
I am import the vertex using:
...
2
votes
1answer
111 views
Using ParametricNDSolveValue with parameter-dependent region to solve for a flow field around an airfoil via FEM
I am looking for a way to have a parametric solution to a potential flow problem using FEM around an airfoil (as an initial bc for the inviscid bc problem), where the parameter to be varied has direct ...
4
votes
3answers
264 views
How to make a high resolution mesh from RegionIntersection in 3D
I want to make a high-resolution 3d model of the Reuleaux tetrahedron by using Mathematica
The Reuleaux tetrahedron is the intersection of four balls of radius s centered at the vertices of a ...
3
votes
2answers
70 views
5
votes
3answers
114 views
How to convert cuboid to mesh efficiently
cuboids =
Table[Cuboid @@ (pts = RandomReal[100, {2, 3}]), {i, 10000}];
Method1:
...
5
votes
4answers
177 views
CantorMesh for a fat cantor set
CantorMesh[n] gives the $n$-th level approximation to the standard no-middle-(1/3)-Cantor set.
Is there a quick way to obtain a similar mesh region for the no-...
4
votes
3answers
236 views
How can I add a few specific mesh (altitude-like level) curves to a plot?
I'm plotting the numerical solution of a differential equations, using the altitude-like level curves as a mesh. It's fine, but I would like to add three specific altitude levels as thick red, green ...
3
votes
2answers
85 views
4
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3answers
173 views
How to draw borders around tiles of the same color?
I'm having difficulties with a project to show random tiles with a few random colors. Here's the code that I need to modify:
...
4
votes
1answer
85 views
ElementMeshInterpolation on a BoundaryMesh
It appears as though ElementMeshInterpolation does not play nice with the element meshes produced by BoundaryMesh
...
4
votes
2answers
187 views
1D mesh generation for PDE solution
I'm trying to solve a system of two PDE that are dependent on time and distance (H[x,t] and P[x,t]). I'm solving the problem using the method of lines but I want to generate myself the mesh and ...
0
votes
0answers
33 views
Define BoundaryMeshRegion from matrix of data
Say I have a matrix 'm' with 2 columns and 'r' rows. I want to define a mesh region using each row in the matrix as a point coordinate. Something like the R=BoundaryMeshRegion[{m},Line[1,2,3....,r]] . ...
6
votes
3answers
213 views
Regions for numerically defined Toroidal surfaces
I have data like this:
DataVisualizationPlot = ListPointPlot3D[data]
And would like to obtain the representing surface like this:
...
4
votes
1answer
65 views
How to obtain a Region from a numerical (!) function
I'd like to achieve a Region from a purely numerically defined function.
Like this one:
...
16
votes
2answers
403 views
3D Inclusion with structured mesh and coarse and arbitrary matrix
I am wondering if there is a simple way to define a structured 3D mesh (inclusion) like e.g. that
and surround it with a corse and unstructured Matrix. It should be possible to refine both more or ...
14
votes
2answers
1k views
Smoother jelly / water effect on an image
I'm trying to achieve a jelly / water surface effect. I'd like it to be a bit smoother. Here I am taking a triangulated rectangle and perturbing all points by a little random noise for each frame. ...
3
votes
1answer
52 views
How do I create an STL file from nearest neighbour graph edges?
I'm trying to figure out to deal with (and design) .stl files within Mathematica.
As an example, I would like to generate a FCC lattice without the atoms (but connecting all nearest neighbours), and ...
2
votes
1answer
96 views
Exporting several Pyramid to a stl file
I made some 3D structure including several Pyramid and tried to export it to stl file.
(I have referenced this link : Exporting several prisms (or Polyhedrons) to stl (with filled inner space))
It ...
2
votes
1answer
38 views
5
votes
2answers
292 views
Using fewer mesh lines, 3D graphics
I want to make the Final use fewer mesh lines,
the ideal version will look like the second image.
Where the triangle shape is more clear and clean. Can anyone give me some advice on how to fix my code?...
1
vote
0answers
57 views
MeshRegion automatically merges vertices that have the same position in space
I sometimes work with surface meshes that have self-intersections (immersions rather than embeddings). MeshRegion usually doesn't have any problems dealing with ...
0
votes
0answers
49 views
Intersection Region of two Conic Hull
I have the following semi-infinite conic hull,
r1=ConicHullRegion[{{0,0,0}},{{-1,0,0},{0,-1,0},{1,0,1}}];
r2=ConicHullRegion[{{0,0,0}},{{-1,0,0},{0,-1,0},{0,1,1}}];
...
4
votes
0answers
44 views
Drawing tools eyedropper crashes Mathematica 12.1 with MengerMesh
Mathematica 12.1.1 under macOS Catalina 10.15.7.
In a new notebook, evaluate: MengerMesh[0, 3]
Click once on the output's graphic image, which causes the bounding ...
3
votes
3answers
122 views
Equipotential surfaces using ParametricPlot
So I'm trying to plot lines on which the following function is a constant
$$
\frac{\left(-\Sigma (r,0.99,\theta )+2 r^2-0.99^2 r \sin ^2(\theta )\right)^2}{\Delta (r,1,0.99) \Sigma (r,0.99,\theta )^3}+...
7
votes
3answers
286 views
Identify the Vertices and Lines around the edges of a free surface - Mesh/DiscreteGraphics
To write a mesher that closes a mesh surface using an implied surface from a boundary spline curve and mesh generated using DiscreteGraphics, I need to identify the Vertices and Lines around the edges ...
0
votes
0answers
68 views
Closing Boundary Mesh with closed 3D Spline Curve
I am trying to make a 3D solid (with BoundaryMeshRegion) from surfaces created by spline curves.
In the follow simple example, I need to close the ends of this irregular tubular shape using boundaries ...
2
votes
1answer
69 views
How to remove the parallelepiped that encloses the writing or make it invisible?
I have this code that I found somewhere and I love what it does, I've been checking the "line" command to remove the line or make it invisible but I can't get it, and the other part of the ...
1
vote
2answers
115 views
Create a “loft” surface from two BSplineCurves?
Is there a way to take two arbitrary BSplineCurves and create a loft surface? I would like to then create a mesh to send to NDSolveValue.
2
votes
1answer
107 views
Create graded mesh
I want to create graded mesh inside a cube, with finer mesh in the left half and a coarser mesh in the right half. My plan was to partition the cube with a 2D plane and then generate boundary mesh ...
3
votes
1answer
52 views
Export Discretized ImplicitRegion as step using OpenCascade
Following the reply by @user21 to this post on exporting a region to a step file, I tried to do the same for a Discretized ImplicitRegion, but OpenCascadeShape didn't appear to work. Is there a switch ...
7
votes
1answer
200 views
1
vote
1answer
81 views
How do I properly define and work with region unions?
Suppose I have two regions defined by two hexahedrons (slightly adapted from this question):
...
1
vote
1answer
41 views
How do I get `ArrayMesh` to reverse the order of data in a 3D array?
The following array has non-zero entries in the cells where all three indices are equal:
foo = SparseArray[{i_, i_, i_} -> 1, {4, 4, 4}]
When I try to render ...
3
votes
2answers
111 views
OpenCascadeLink Viewing and Assigning Element Markers
I recently upgraded to MM 12.1 so I could use OpenCascadeLink for 3D meshing following the excellent answer to a question regarding 3D meshing:
3D Meshing Internal regions
Assigning boundary element ...
10
votes
1answer
330 views
How to mesh a French biscuit (modulated ellipsoid)
I would like to create a boundary mesh of the following ellipsoid, whose thickness is modulated along its long axis:
The surface parametrization I used for it is:
...
6
votes
1answer
171 views
3D FEM Meshing Internal Regions
I am trying to set up a 3D element mesh with intersecting regions having different mesh densities. I am having difficulty setting up the defining boundary meshes from which I will then apply ...
3
votes
1answer
118 views
Turn a region and points inside that region into a mesh
I have a region defined by a polygon and a few points that are inside that region. I'd like to create a mesh where its boundary is the boundary of the region and the vertices interior to the mesh are ...
0
votes
0answers
35 views
Dump Curvature Information for 3d Models
Is anyone aware of any utility to generate and dump Principal, Gaussian and Mean Curvatures for a 3D Model or a set of points? I have reserched following tools -
meshlab
cloudcompare
They are able to ...
5
votes
1answer
185 views
Mass Transport FEM Using Quad Mesh
This question is a follow-up to my previous question and an attempt to implement @Tim Laska's excellent approach of setting up an anisotropic quad mesh. I'm solving a similar problem to @Tim Laska's ...
1
vote
0answers
92 views
Why is there no heat being transfered in my program?
I have been working on this code and am new to this coding language. I have been trying to model the transfer of heat through a hot plastic being cooled in a water bath. For some reason I have not ...
5
votes
2answers
243 views
How to fill in interior in a mesh region
Say I have a mesh region which encloses a region. How do I get a mesh region where this region is filled? Take for example the meshregion below:
...
1
vote
0answers
47 views
obtain the analytics region from mesh or vtk file
Is it possible to obtain the region inequalities from a mesh file (vtk-file).
On gmsh I build a Sphere, and with Mathematica I would like to obtain the analytics region function, that's is possible?.
...
2
votes
1answer
93 views
ToElementMesh Error/General meshing strategies
I am trying to create a mesh using ToBoundaryMesh as opposed to DiscretizeRegion. I was hoping this would be a better strategy ...
6
votes
1answer
191 views
Improving mesh and NDSolve solution convergence
I have developed the code below to solve two PDEs; first mu[x,y] is solved for, then the results of mu are used to solve for phi[x,y]. The code works and converges on a solution as is, however, I ...
5
votes
2answers
256 views
Mesh Generation help
I am having trouble generating a mesh of a rectangle inside another rectangle. I have been following the steps on this article: https://reference.wolfram.com/language/PDEModels/tutorial/HeatTransfer/...
5
votes
3answers
289 views
How to discretize a parametric polar surface ensuring the correct periodicity of the mesh
I am trying to discretize a polar surface using a combination of ParametricPlot3D and DiscretizeGraphics. Unfortunately, the ...
1
vote
0answers
50 views
Why does ConvexHullMesh give inconsistent output stuctures?
I know much of the stuff in ConvexHullMesh needs some TLC convexhullmesh-inconsistency
But, can anyone see why this would produce inconsistent output:
Case 1 (expected behavior):
...
