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[Zesen Qian <>]

Hi Sebastien,

Thanks for this. I wrote the program myself and I'm using surface_mesh
instead of mesh_3. Question: Why will Mesh_3 be faster? From what I
understand this will not only generate facets but also cells inside
the shape? How will that accelerate the process?

And in particular, if I'm not interested in the cells, how should I
set the parameters concerning it? i.e., cell_radius_edge_ratio and
cell_size.

Best,
Zesen

On Tue, May 22, 2018 at 2:25 PM, Sebastien Loriot (GeometryFactory)
<>
 wrote:
> Note that this PR : https://github.com/CGAL/cgal/pull/3043
> will bring some noticeable speed up as well as parallel mesh algorithm.
>
> Best,
>
> Sebastien.
>
>
> On 05/22/2018 07:18 PM, Zesen Qian wrote:
>>
>> Hi Sebastien,
>>
>> Sorry for keep spamming your inbox - but I found how to sample areas
>> differently based on variety. For future reference, the parameter
>> distance_bound constrols the max distance from every generated facet
>> to the surface. So when the same value applies to different areas, the
>> areas with more details will get sampled more.
>>
>> Thank you so much for the help!
>>
>> Best,
>> Zesen
>>
>> On Tue, May 22, 2018 at 11:11 AM, Zesen Qian 
>> <>
>>  wrote:
>>>
>>> Hi Sebastien,
>>>
>>> I think I was mistaken - I tried it again and it seems that I don't
>>> have to do too much about the angle_bound - adjusting other parameters
>>> would suffice to give a decent result.
>>>
>>> However, it is indeed slow. One feature of my mesh is that it donsn't
>>> have to be evenly sampled - some areas require more details than
>>> others.  Can I do some trick so that those area receive extra
>>> sampling, while other more monotone area get less, so I can save some
>>> processing time?
>>>
>>> Best,
>>> Zesen
>>>
>>> On Tue, May 22, 2018 at 10:26 AM, Zesen Qian 
>>> <>
>>> wrote:
>>>>
>>>> Hi Sebastien,
>>>>
>>>> Thanks for this. I don't know if that's a similiar thing, but I tried
>>>> https://doc.cgal.org/latest/Surface_mesher/
>>>> by a distance function(with AABB_tree and side_of_triangle). Seen from
>>>> the source code of the plugin, it's very similar.
>>>>
>>>> To get a decent result it's quite slow. If I set the angular bound to
>>>> 90 degree(more than 30),  the algorithm is not garanteed to
>>>> terminate(and indeed in my case). My mesh has some very thin layers
>>>> that's easy  to be ignored by meshing, so I don't expect this method
>>>> to work.
>>>>
>>>> What I'm now trying is simply using the "solidify" modifier in
>>>> Blender, and fix the potential self-intersections using refining and
>>>> outer-hull operation, and then use boolean operation with the original
>>>> mesh to get a offseted mesh. I'm using libigl to do these tasks.
>>>>
>>>> Best,
>>>> Zesen
>>>>
>>>> On Tue, May 22, 2018 at 9:59 AM, Sebastien Loriot (GeometryFactory)
>>>> <>
>>>>  wrote:
>>>>>
>>>>> There is indeed nothing official in CGAL. However, in the Polyhedron
>>>>> demo we wrote a small plugin that is meshing the distance function to a
>>>>> mesh
>>>>> and the output is by construction guaranteed to be free from
>>>>> self-intersections. However sharp features are not correctly meshed if
>>>>> not protected.
>>>>>
>>>>> Go into 3D Surface Mesh Generation -> Offset meshing once having loaded
>>>>> a polyhedron.
>>>>>
>>>>> Source code is here:
>>>>>
>>>>> https://github.com/CGAL/cgal/blob/releases/CGAL-4.12-branch/Polyhedron/demo/Polyhedron/Plugins/Surface_mesh/Offset_meshing_plugin.cpp
>>>>>
>>>>> HTH,
>>>>>
>>>>> Sebastien.
>>>>>
>>>>>
>>>>> On 05/17/2018 07:44 PM, Zesen Qian wrote:
>>>>>>
>>>>>>
>>>>>> Hi list,
>>>>>>
>>>>>> I have a triangulated, closed mesh which is free of any degeneracies.
>>>>>> Is there any reliable way to offset this mesh? By reliable I mean the
>>>>>> result mesh should be free of any degeneracies.
>>>>>>
>>>>>> I searched on Internet and there is simply not an library/program
>>>>>> available that can do this. I guess CGAL isn't capable of this either,
>>>>>> but I believe people on this list should be familiar with this topic
>>>>>> and maybe offer some comments.
>>>>>>
>>>>>> Thank you.
>>>>>>
>>>>>> Best,
>>>>>> Zesen
>>>>>>
>>>>>
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>>>>>
>>>>>
>>
>
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