dengwirda / mesh2d Goto Github PK

I am running into a strange error when meshing a 3-part geometry. The traceback is as follows:

Index in position 1 exceeds array bounds (must not exceed 269).
Error in deltri2 (line 138)
    tmid = vert(tria(:,1),:) ...
Error in refine2>cdtbal0 (line 311)
        tria,tnum] = deltri2(vert,conn, ...
Error in refine2 (line 260)
        cdtbal0(vert,conn,tria,tnum, ...

The index in question exists in the tria variable and has a value of 270 (vert only goes up to 269). Oddly, when I mesh the three parts separately, or even in sets of two parts at a time--i.e. parts 1 and 2, parts 2 and 3, etc.--then I do not encounter this error.

Do you expect that this may be indicative of some kind of input error? Any suggestions of things to try? Let me know if this is simply too difficult to diagnose without some kind of example geometry and I'll see what I can do...

It seems that when a region has a very high aspect ratio (e.g. a triangle with a very small angle), nodes are inserted into the border even when I have ref1 set to preserve. Is this the expected behavior? Is there anything I can do to be more strict about preserving edge nodes?

Excellent work! I found this program very helpful. I'm wondering how can I extract the boundary nodes/edges of the triangular mesh？I'm using the mesh to set up a finite element model

Hey,
I was wondering how you would suggest creating a file like the airfoil.msh or lake.msh from a histological section like this: histological slice. I would want to define the layers as edges so I can refine the mesh at each transition. They might be more complicated than just a straight lines, otherwise I would define them like in tridemo(0)
Cheers!

Hey Darren,

I have a meshing problem where I'd like to constrain the red lines in the blue polygon region below. There's a lot of constraints and what I find is that passing some configurations of constraints lead to non-convergence.

Are there any geometry pre-processing/clean up that I can do with the constraints that I can do to perhaps avoid this?

Thanks!

I am wondering if it is possible to use the refine2() function to generate a mesh in which no new nodes are added on the border of the polygonal geometry. I have experimented with the various refine2 options (RHO1, SIZ1, SIZ2, etc.) and have been unable to achieve this, though my understanding of the effect of some of the options is limited. In my case, I care more about the no-new-border-nodes requirement than the final mesh quality. Is there any way to achieve this, either directly or indirectly?

Hi Professor Darren Engwirda,

I have a narrow region and I hope to get the mesh as that in the picture.
My way in other mesher might be specifying the mesh nodes on the edge and the mesh size for that region. I understand the quality in the region is not very good, but that's just I hope to have.
is it possible/what is the good way to do this with mesh2d?

sorry it is not an issue, but I don't know where to ask.

Thanks!
George.

Hi, this is not an issue per say. I was wondering how to make a constrained delaunay where all triangles are acute ?

Hi, I'm trying to download mesh2d from the github repository. But when I ran some sample code in matlab, it's still saying that the function is not found. Could you suggest the correct way of downloading the function? Thank you!