CGAL users discussion list

[Hui Ding <>]

Hello everyone,

 

I have some data files that contain the values 3D points of the object 3D, and I'd like to use CGAL to represent the object. I just looked into the chapter22 of manuel, and i have some questions about both concept of science and use of library, I will appreciate it, if someone gives some helps:

 

1) I can see that a vertex has 0-face, the edge has 1 face, and a facet has 2 faces, but I don't understand how a cell has 3 face? why not 4, if a cell is a 3 simplex(tetrahedron)?

2) From some basic exemple of chapiter 22, i saw that we get the triangulation information by using "ostream", but I dont understand what every value stands for. (the dimention, number of finite, non-combinatorial, the number of cells are clear, but the others i cant figure out, anyone can help?).

3) Could I easily put my 3D points data to Triangulation_3, and then use the ostream to output the triangulation information of this object? and is there any "Viewer" can read this information and show the object in 3D? Or do i need to write it myself what chapiter do i need to read?

4) Once I construct the triangulation of my object 3D, I need the normal of every facet of every cell, is there already some functions who do that? or i need to calculate myself? how?

5) I read only chapter 22 for my work right now(cause someone told me so), but if anyone has some conseils to learn the 3D triangulations like some chapiters or some tuturials corresponding to 3D triangulation or something else, please tell me?

 

Thanks!

 

Best,

Hui DING

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