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matlabpoint-clouds

How to save a 3D data matrix as pointcloud in Matlab?

I have a 3D data matrix which contains information about a scene (which voxels are free / occupied and belong to which class).

So far to plot the data I have to plot 2D slices using imagesc.

I'd like to plot the data as a pointcloud using Matlabs pcshow which should only display occupied voxels and the display the rest as empty space.

How can I convert my 3D matrix into a pointcloud object?

Solution

  • For some NxMxK matrix A where A == 255 indicates free voxels:

    % make coordinate grid the size of A
[X,Y,Z] = meshgrid(1:size(A,1),1:size(A,2),1:size(A,3));
% move to xyz format
xyz=[X(:) Y(:) Z(:)];
% show points which are not free and where group values are used as color (scaled by to current colormap)
pcshow(xyz(A~=255,:),A(A~=255))