step-54 extends to 3d geometry

[yy.wayne]

I'm running step-54 on some different geometries. I think there are two core manifold projection: line projector for edge & surface projector for cells(in 2d) or faces(in 3d).

First, I refine mesh for a plane 2d geometry so face projector is not needed. Only ArclengthProjectionLineManifold is applied and refined successfully. Here "face of mesh" is 1d and "cell of mesh" is 2d.

Then I met trouble for 3d case. Now "edge of mesh" is 1d and "face of mesh" is 2d. My understanding is now only surface projection is required and line projection is meaningless. However I keep run into error that "point is not on manifold" even tolerance is 100000 times of original iges tolerance.

How shall I modify the tutorial? Thank you.

[Wolfgang Bangerth]

On 10/16/22 09:00, 'yy.wayne' via deal.II User Group wrote:
>
> Then I met trouble for 3d case. Now "edge of mesh" is 1d and "face of mesh" is
> 2d. My understanding is now only surface projection is required and line
> projection is meaningless. However I keep run into error that "point is not on
> manifold" even tolerance is 100000 times of original iges tolerance.

In 3d, we first refine the edges and then the faces. You need manifolds for
both 1d and 2d objects.

Best
W.

--
------------------------------------------------------------------------
Wolfgang Bangerth email: bang...@colostate.edu
www: http://www.math.colostate.edu/~bangerth/

[yy.wayne]

Thanks for your reply.

But I don't find a iterator for edge in CellAccessor. There are cell, face, and vertex iterators, but lArclengthProjectionLineManifold requires a 1d topology. Which part of  mesh should I set manifold?

[yy.wayne]

There are only several typedef of line_iterator, and a private function begin_line. I don't think they works here.

[Wolfgang Bangerth]

On 10/16/22 19:21, 'yy.wayne' via deal.II User Group wrote:
>
> But I don't find a iterator for edge in CellAccessor. There are cell, face,
> and vertex iterators, but lArclengthProjectionLineManifold requires a 1d
> topology. Which part of  mesh should I set manifold?

cell->line(l) or cell->face(f)->line(l) gives you what you want.

[yy.wayne]

Thanks it seems manifold ids are set correctly now.

But I still get "point is not on manifold" error now even with big tolerance.I think my coarse mesh conform to the geometry similar to the bow_surface in step-54. The IGES geometry is generate by COMSOL, and mesh file transformed from COMSOL to msh by gmsh. 

Best,

Wayne

[yy.wayne]

I think my mistake is I only set one wires TODO_Shape and one shell TODO_Shape to the projector...

So for a imported geometry one has to manually set these properties to corresponding faces and lines? What's the suggested CAD software to view IGES's TODO_Shape? In my case, reading the sphere shell into deal.II gives 9 shell, but from GMSH or COMSOL I cannot view those 9 shells.

Secondlly, which mesh format keeps boundary information & solid information when imported to deal.ii? I read the .msh file from GMSH but boundary tags are discarded by deal.ii. It's ideal if internal boundary tags are kept.

Best,

Wayne

[Wolfgang Bangerth]

On 10/17/22 00:09, 'yy.wayne' via deal.II User Group wrote:
>
> So for a imported geometry one has to manually set these properties to
> corresponding faces and lines? What's the suggested CAD software to view
> IGES's TODO_Shape? In my case, reading the sphere shell into deal.II gives 9
> shell, but from GMSH or COMSOL I cannot view those 9 shells.
>
> Secondlly, which mesh format keeps boundary information & solid information
> when imported to deal.ii? I read the .msh file from GMSH but boundary tags are
> discarded by deal.ii. It's ideal if internal boundary tags are kept.

This exceeds my knowledge of meshing and geometry software. Maybe others here
can help with those questions?

[yy.wayne]

Thanks

Let me simplify my question here for someone to answer it later.

In short, I want to import a mesh and a CAD file, set the CAD's manifold to mesh, and refine mesh according to CAD's geometry like step-54 but in 3-dimensional. For example, a sphere shell.

1. What's the best CAD and MESH software to generate the files for deal.ii to read and process? I hope boundary tags on internal faces are kept. COMSOL, GMSH, Cubit, etc.
2. How to adapt the code in step-54? My IGES file gives more than one shell and wires.