MATLAB: How to plot some 3-D data using transparency to visualize all values

Question

I have amplitude data that lives in 3-D space that I would like to visualize. Currently I have created a series of cross-sections by creating multiple surfaces using the "surf" function, and stacking them on top of each other. However, this makes it very hard to see the data in the middle, or from other angles. How can I best visualize amplitude data throughout the entire volume?

Answer 1

MATLAB provides many methods for visualizing volumetric data, the list of available functions can be found here:

https://www.mathworks.com/help/matlab/volume-visualization.html

One popular method is to use the "slice" function, in conjunction with transparency to visualize amplitude data living in a dense 3-D space. Below is a link to the Documentation for the "slice" function, along with two links providing nice examples using this function.

Slice: 

https://www.mathworks.com/help/releases/R2017a/matlab/ref/slice.html?searchHighlight=slice&s_tid=doc_srchtitle

Example 1: 

https://www.mathworks.com/help/matlab/visualize/exploring-volumes-with-slice-planes.html

Example 2: 

https://www.mathworks.com/help/matlab/creating_plots/selecting-an-alphamap.html

Below is a sample workflow with spacial data X, Y, and Z, and the data values corresponding to each location in V:

% space slices out without the data
sx = linspace(min(X(:)),max(X(:)),7);
sy = linspace(min(Y(:)),max(Y(:)),4);
sz = linspace(min(Z(:)),max(Z(:)),8);
% create the slices 
% in this example, there are 19 surfaces created
h = slice(X, Y, Z, V, sx, sy, sz);
% set properties for all 19 objects at once using the "set" function
set(h,'EdgeColor','none',...
    'FaceColor','interp',...
    'FaceAlpha','interp');
% set transparency to correlate to the data values.
alpha('color');
colormap(jet);