Scanning a pipe to obtain many sections, each section has 7000 points, the distance between the points is very close. However, each section is far away, and there are more than 10 such sections. How to construct a pipe 3D model(mesh) through these points?
sxbug
Give here a picture of your pipe scan, cos absolutely unclear where are points settle down on circle or inside the circle sections, and what do you need to get, e.g. only a surface mesh or tetrahedralized volume of your pipe.
Pavel
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Ok sxbug,
Your PLC of scan data could be meshhing with Gmsh or Tetgen and there are own visualizers like
tetview-win and imported to GLScene' TFreeForm with .ply file format
Pavel
Hi Pavel
I can't download their example program. Maybe there's something wrong with their website.
Thank you very much. This may really solve my problem.
sxbug
sxbug,
Strange, it has address http://www.tetgen.org/
If you cannot use make or cmake the source code of tetgen with bcc64 or visual studio c++compilers then use executables in attachment. See Manual for details. We need to include support of tetgen or qhull (qhull.org) in the next v.2.0 of GLScene for 2d/3d meshing and tetrahedralization/voronoi diagrams constraction.
Pavel
Hi Pavel
I've read the documentation of tetgen, which is a very great work if it can also be integrated into glsense. But my point cloud is a special format, only x, y, Z coordinates, and the points on the section are very dense, and the distance between the sections is far, which is more difficult to rebuild the mesh. Thank you for your help. I'll think about it for myself.
sxbug
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Hi Pavel
I've read the documentation of tetgen, which is a very great work if it can also be integrated into glsense. But my point cloud is a special format, only x, y, Z coordinates, and the points on the section are very dense, and the distance between the sections is far, which is more difficult to rebuild the mesh. Thank you for your help. I'll think about it for myself.
sxbug
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Hi, i think you need some extra manipulations :
1st : Remove or weld the points wich are too closed with the tolerance you want
2nd : Generate contours lines from those points
3rd : Use a line simplification algortihm like Ramer-Douglas-Peucker
4th : Smooth lines by using curve (spline or bezier)
5th : Create your mesh by extruding the new edges and adjust normal inside/ouside
Cheers
Last edit: Jerome.D (BeanzMaster) 2020-04-21
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Hi guys,
There are a lot of mesh generators using input points, but more advanced is Gmsh for cunstructive surface meshes. You will see meshing for a scan of an artery in Overview. It's the same task as by sxbug pipes. But for tetrahedralization it includes also Tetgen. All open source and free of charge.
Pavel
With such a set of points, how to get a 3D mesh?
Scanning a pipe to obtain many sections, each section has 7000 points, the distance between the points is very close. However, each section is far away, and there are more than 10 such sections. How to construct a pipe 3D model(mesh) through these points?
Thanks
Sxbug
sxbug
Give here a picture of your pipe scan, cos absolutely unclear where are points settle down on circle or inside the circle sections, and what do you need to get, e.g. only a surface mesh or tetrahedralized volume of your pipe.
Pavel
Hi Pavel
I only have a model now,just like:
Scan a section to get a lot of points. Just like:
I want to get the surface mesh of the inner interface of this pipe through these points of multiple sections.
Thanks
Ok sxbug,
Your PLC of scan data could be meshhing with Gmsh or Tetgen and there are own visualizers like
tetview-win and imported to GLScene' TFreeForm with .ply file format
Pavel
After zooming in many times, the dots on a line may be arranged like this appearance.
Hi Pavel
Thanks. Let me try it !
sxbug
Hi Pavel
I can't download their example program. Maybe there's something wrong with their website.
Thank you very much. This may really solve my problem.
sxbug
sxbug,
Strange, it has address http://www.tetgen.org/
If you cannot use make or cmake the source code of tetgen with bcc64 or visual studio c++compilers then use executables in attachment. See Manual for details. We need to include support of tetgen or qhull (qhull.org) in the next v.2.0 of GLScene for 2d/3d meshing and tetrahedralization/voronoi diagrams constraction.
Pavel
sxbug
Simply type in command line
tetgen example.poly
and it'll generate all elements (edges), faces and nodes.
Pavel
Hi Pavel
I've read the documentation of tetgen, which is a very great work if it can also be integrated into glsense. But my point cloud is a special format, only x, y, Z coordinates, and the points on the section are very dense, and the distance between the sections is far, which is more difficult to rebuild the mesh. Thank you for your help. I'll think about it for myself.
sxbug
Hi Pavel
I've read the documentation of tetgen, which is a very great work if it can also be integrated into glsense. But my point cloud is a special format, only x, y, Z coordinates, and the points on the section are very dense, and the distance between the sections is far, which is more difficult to rebuild the mesh. Thank you for your help. I'll think about it for myself.
sxbug
Hi, i think you need some extra manipulations :
1st : Remove or weld the points wich are too closed with the tolerance you want
2nd : Generate contours lines from those points
3rd : Use a line simplification algortihm like Ramer-Douglas-Peucker
4th : Smooth lines by using curve (spline or bezier)
5th : Create your mesh by extruding the new edges and adjust normal inside/ouside
Cheers
Last edit: Jerome.D (BeanzMaster) 2020-04-21
Hi guys,
There are a lot of mesh generators using input points, but more advanced is Gmsh for cunstructive surface meshes. You will see meshing for a scan of an artery in Overview. It's the same task as by sxbug pipes. But for tetrahedralization it includes also Tetgen. All open source and free of charge.
Pavel
Last edit: Pavel Vassiliev 2020-04-21
@Jerome.D，@Pavel
Thanks for your help. I am trying.
sxbug