CGAL users discussion list

[Jane Tournois <>]

Hi,

the feature preservation can indeed preserve only 0D and 1D features.
However, the polyline that makes the junction between the red, blue, and empty areas is a 1D feature. If you want to preserve it, you need to give it as a polyline to the feature protection function.

About surfaces, they cannot be preserved exactly, but all boundary vertices of the output mesh belong to the surface of your input. For an image, the minimum edge length you choose for the surface should be larger than the voxel size, otherwise the output mesh will follow the "steps" of the boundary.

Best,

-- 
Jane Tournois, PhD
R&D Engineer at GeometryFactory
http://www.geometryfactory.com/

Le 14/08/2015 15:49, Andrew Crozier a écrit :

Hi,

I am using CGAL to mesh 3D medical images described with the CGAL::Labeled_image_mesh_domain_3 class. These images have labels assigned to different regions, much as in the example:

http://doc.cgal.org/latest/Mesh_3/index.html#Mesh_3DomainsFromSegmented3DImages

However, while the internal boundary between the different labels in the resulting mesh are smooth, on the external surface there are small 'gaps' in the mesh at the join, which I would like to avoid (as in the image below).



Do you know of some method by which I can enforce a smooth external surface to the mesh? I had a look at the feature preservation (with a view to enforce preservation of the external 2D surface), but it seems that only 0D and 1D features may be preserved.

Best wishes,
Andrew Crozier

---

Andrew Crozier

+43 316 380 7759

Postdoctoral Researcher
Institute for Biophysics
Medical University of Graz

Attachment: pngT3LAszVWHT.png
Description: PNG image