MATLAB: Using CData to paint some polygons

colourMATLABsometrianglestrisurf

Hi,

is it possible to paint only some of the triangles of a trisurf surface? I have tried to use NaN's as CData for the patches I didn't want to colour but it ended up not colouring any of the triangles at all, including the ones whose CData values weren't NaN. I'm using CData as a n x 1 matrix, with each triangle having its own value.

Thanks in advance

Best Answer

I’m not certain what you want to do, but one option is the alpha function, or setting the Alpha property if you want them transparent. The other option is to colour the ‘uncoloured’ faces white = [1 1 1].

Related Solutions

MATLAB: Shading (or colouring) area under the curve

I just found a MATLAB function area() which will do the job! B

MATLAB: Coloring faces of isosurface corresponding to intensities in a 3D plot.

Yes, you want to set the FaceVertexCData property of the patch object to your data, and the FaceColor property to 'flat'.

Here's a simple example:

%%Create an isosurface
[x y z v] = flow;
p = patch(isosurface(x, y, z, v, -3));
daspect([1 1 1])
view(3)
%%Compute the area of each face
u = p.Vertices(p.Faces(:,2),:) - p.Vertices(p.Faces(:,1),:);
v = p.Vertices(p.Faces(:,3),:) - p.Vertices(p.Faces(:,1),:);
n = cross(u,v);
a = sqrt(n(:,1).^2 + n(:,2).^2 + n(:,3).^2) / 2;
%%Color the faces with the area
p.FaceVertexCData = a; 
p.FaceColor = 'flat';
p.EdgeColor = 'none';

Instead of the area, you would use your calculated data. The FaceVertexCData property should be a vector whose length is the same as the number of faces in your patch.

Best Answer

Related Solutions

MATLAB: Shading (or colouring) area under the curve

MATLAB: Coloring faces of isosurface corresponding to intensities in a 3D plot.

Related Question