MATLAB: surf Plot after rotating my data

Question

This question entails rotating an image given as a 3D matrix where the first dimension is width, 2nd dimension is height, and 3rd dimension contains x,y,z coordinates.

Currently I am plotting a surface using the following code

    Fig.sub1im=surf(ToFparam.ROI.XYZ(:,:,1),ToFparam.ROI.XYZ(:,:,2),ToFparam.ROI.XYZ(:,:,3),zeros(ToFparam.ROI.height,ToFparam.ROI.width,3));

Now, I have a 3-D matrix where it's a 100x50x3. All x data is in the first...page or layer of the 3rd dimension, y is the second layer...z the third. Now I need to apply a 3x3 rotation matrix on the x y and z data. I know how to reshape a matrix to do this I think....just put it into a 3 row by...50000 column matrix then apply the matrix.

Next I need to update my plot in a loop. I was going to then do the following, where I have also included my new matrix calculation.

ToFparam.ROI.XYZ_Vector = ToFparam.ROI.XYZ;
ToFparam.ROI.XYZ_Vector = reshape(ToFparam.ROI.XYZ, [size(ToFparam.ROI.XYZ,1)*size(ToFparam.ROI.XYZ,2),3]);
ToFparam.ROI.XYZ_Vector = ToFparam.ROI.XYZ_Vector';
ToFparam.ROI.XYZ_DICOM = inv(DICOMparam.calib.navi2dicom(1:3,1:3))*inv(Naviparam.data.Endo_RefHomMat(1:3,1:3))*ToFparam.ROI.XYZ_Vector;

%refresh plot standard cuts
set(Fig.sub1im,'CData', Color);
set(Fig.sub1im, 'XData', ToFparam.ROI.XYZ_DICOM(1,:) + DICOMPos(1)/Fig.sub2samp);
set(Fig.sub1im, 'YData', ToFparam.ROI.XYZ_DICOM(2,:) + DICOMPos(2)/Fig.sub2samp);
set(Fig.sub1im, 'ZData', ToFparam.ROI.XYZ_DICOM(3,:) + DICOMPos(3)/Fig.sub2samp);

When I update my plot, I get no errors, but it doesn't look like it's plotting it correctly. It seems like it makes a huge offset on my data and positions it somewhere I don't want it to be positioned. I wouldn't expect that a rotation matrix effects the scaling, just the orientation. Let me know if there are any faster/better ways to accomplish this surf plot, thanks!

spaderdabomb spaderdabomb · Accepted Answer · 2013-07-26T06:56:37

For anyone interested, I have found the solution.

If you ever want to rotate a 3-D matrix where the x,y,z data is located in the 3rd dimension, use the following for maximum speed and efficiency.

    [m,n,z]=size(inMatrix);
outMatrix=reshape((A*(reshape(double(inMatrix),[m*n 3]))')',[m n 3]);

Where inMatrix is your initial 3d matrix, outMatrix is your output 3d matrix, and A is your rotation matrix. Can be extremely useful when wanting to code rotations in images, since images will have 2 dimensions along their width and height, and the 3rd dimension will be the x, y and z coordinates. This will allow you to easily plot an initial data set, rotate it, then replot it.

MATLAB: surf Plot after rotating my data

1 Answers