[vtkusers] Generating a surface with equilateral triangles from point data

[Steven Koch]

Hello Michael,

Please send me your  "code"....  Thanks much.....

I wrote a 'remesher' a few years ago that generates a 'varying-density 
equilateral' mesh on top of another mesh based on scalar values at each 
vertex.  For example. the remesher would generate smaller triangles in 
regions with higher scalar values and larger triangles in regions with 
lower scalar values.  This would be a common function when the scalar 
values represent the surface's rate of curvature.  However, I was using it 
to generate varying-density meshes based on light-source illumination 
(i.e. meshes with a shadow effect for the laser crystal market) .  It 
works very well.

Are you aware of a similar product?  Should I make my code available? How? 
 Where?  Why?

Best Regards,

Stephen Koch



From:
Michael Jackson <mike.jackson at bluequartz.net>
To:
vtkusers at vtk.org
Date:
11/13/2008 08:43 AM
Subject:
Re: [vtkusers] Generating a surface with equilateral triangles from point 
data



I have the general code to do that if you want it. It is also based on 
the cmu "Quake" library.

Mike

On Nov 13, 2008, at 9:33 AM, Simon Drouin wrote:

> I haven't found a solution to that problem in vtk. vtkDelauney2D 
> will generate similar results. My current workaround is to extract 
> vtkPoints from my actor, feed them into the Triangle library (
http://www.cs.cmu.edu/~quake/triangle.html 
> )  and put the resulting triangulation back in a vtkPolyData. 
> Triangle does a very nice job and allows you to specify the maximum 
> angle you want in your triangle as well as the maximum triangle area.
>
> s.
>
>> On Wed, Nov 12, 2008 at 12:41 PM, Steven Boyd <skboyd at ucalgary.ca> 
>> wrote:
>> Hi,
>>
>> How can I generate more or less equilateral triangles from a series 
>> of
>> points that define the perimeter of a closed loop (e.g., an oval)? 
>> When I
>> use vtkTriangleFilter the resulting triangles have poor aspect 
>> ratios (they
>> have vertices on the perimeter of the oval and therefore are quite
>> stretched).   Can somebody suggest an approach where the triangles 
>> generated
>> would be closer to equilateral?  Adding points to the centre would 
>> seem to
>> be necessary, but I was hoping there might be a filter that could 
>> do this
>> without manually adding points.
>>
>> Thanks,
>>
>> Steve

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