Convert a Quadrangle to a Triangle

[luonganh89]

Hi all !

I got stuck in establising an method to Convert a Quadrangle mesh to a Triangle mesh (CFD).
I have a mesh file (.dat) which have information:
Number of Element - Node 1 - Node 2 - Node 3 - Node 4
1 1 2 3 4
2 3 4 5 6
Have anyone done like me. Can share me some information thank you so much

luong anh
pfiev

 

[gsal]

You need to be more specific.
What exactly is the problem?
What is the method that you established and where are you stuck?

 

[AlephZero]

The obvious thing to do is turn each quadrilateral into two triangles by drawing a diagonal. But if the quadrilaterals are curved (i.e. a 3D surface) the results may look different depending on which diagonal you choose.

If that is a problem, maybe you need to find the "center" of the quadrilateral (i.e. the average of the 4 corner points) and join that to the corners to make 4 triangles.

As gsal says it really depends what the triangle mesh will be used for.

 

[luonganh89]

:D of course , I've just wanted to remesh my model, and i write a short code to remesh it and open it by using tecplot , but now i come back home , tomorrow i will send my result to you but i got some trouble @@

 

[LudusRex]

sky

Hello Luong Anh and pfievsky,

Converting a quadrangle mesh to a triangle mesh can be a challenging task, but there are a few methods that can be used. One approach is to divide each quadrangle element into two triangles by connecting the opposite midpoints of the quadrangle. This will result in a mesh with twice as many elements, but will still maintain the same overall shape.

Another method is to use a software or script that can automatically convert quadrangle elements to triangles. This can be done by using algorithms such as Delaunay triangulation, which can generate an optimized triangular mesh from a given set of points.

It is important to keep in mind that the quality of the resulting triangle mesh may vary depending on the original quadrangle mesh and the method used for conversion. It is recommended to carefully evaluate the resulting mesh for any potential issues or errors.

I hope this information helps and good luck with your conversion process!