[vtkusers] vtkImageContinuousDilate3D + vtkMarchingCubes

[Mathieu Malaterre]

Hi all,

	Here is my VTK pipeline: my input is a Black&White image (=result a of 
segmentation process).

                       reader
              |                       |
              |                       |
vtkImageContinuousDilate3D           |
    (dilatation of 2mm)               |
              |                       |
      vtkMarchingCubes         vtkMarchingCubes
              |                       |
            Result1                Result2

	So my results are:
- Result1 is what I call my external mold,
- Result2 is my internal mold.

	With this pipeline I would like Result1 to be distant from 2mm to 
Result2. But to be sure I check the results using M.E.S.H.: 
(http://mesh.epfl.ch/). And I get this result:

http://www.creatis.insa-lyon.fr/~malaterre/vtk/mesh.jpg

	Does anyone knows where could theses errors come from ? How come I get 
a zero distance between my two meshes ?



Thanks for any clue,
mathieu





//------------------------------------------------------------------------
I have also included the text output of M.E.S.H.:

Reading /home/malat/Kitware/Test/DilateMesh/bin/internal-mold.vtk.iv ... 
Done (0.56 secs)
Reading /home/malat/Kitware/Test/DilateMesh/bin/external-mold.vtk.iv ... 
Done (0.58 secs)

                       Model information
      (degenerate faces ignored for manifold/closed info)

Number of vertices:      	     143388	     145808
Number of triangles:     	     286562	     291374
Degenerate triangles:    	          0	          0
BoundingBox diagonal:    	        376	    377.594
Number of disjoint parts:	          1	          1
Manifold:                	        yes	        yes
Originally oriented:     	        yes	        yes
Orientable:              	        yes	        yes
Closed:                  	         no	         no
Surface area:            	     109842	     113310

        Distance from model 1 to model 2

         	   Absolute	% BBox diag
         	           	  (Model 2)
Min:    	          0	          0
Max:    	    17.2337	    4.56408
Mean:   	    0.78959	   0.209111
RMS:    	    1.45881	   0.386344

        Distance from model 2 to model 1

         	   Absolute	% BBox diag
         	           	  (Model 2)
Min:    	          0	          0
Max:    	    1.73206	    0.45871
Mean:   	   0.699088	   0.185143
RMS:    	   0.848846	   0.224804

        Symmetric distance between model 1 and model 2

         	   Absolute	% BBox diag
         	           	  (Model 2)
Min:    	          0	          0
Max:    	    17.2337	    4.56408
Mean:   	    0.78959	   0.209111
RMS:    	    1.45881	   0.386344

                  	Absolute	   % BBox diag	     Expected samples
                  	        	   model 2     	   model 1	model 2
Sampling step:   	 1.88797	       0.5     	     30816	  31789

         	    Total	    Avg. / triangle		Tot (%) area of
         	         	model 1 	model 2 	sampled triang.
Samples (1->2):	   859686	      3	              3	            100.00
Samples (2->1):	   874122	    3.1	              3	            100.00

                                 	     X	    Y	   Z	   Total
Partitioning grid size (1 to 2):	    64	  139	  59	  524864
Partitioning grid size (2 to 1):	    64	  139	  59	  524864

Avg. number of triangles per non-empty cell (1 to 2):	21.46
Avg. number of triangles per non-empty cell (2 to 1):	21.66
Proportion of non-empty cells (1 to 2):          	4.96%
Proportion of non-empty cells (2 to 1):          	4.84%

Analysis and measuring time (secs.):	18.94