How to create 3D surface with different layers that each have their own colormap in matlab?

How can I create a 3D map of the glacier (bedrock + glacier surface + debris surface) with each a different colormap in Matlab? I tried several things but it does not work. Only 1 colormap is used and not a separate one for each distinct layer. I have tried the code above but the plot generates only 1 colormap for all 3 layers (bedrock + glacier + debris). I want the plot to have a distinct colormap for each of the layers. How can I solve this?

close all;
clear;
clc;

% Load data
bedrock = double(geotiffread('bedrock_oct2023.tif'));
icethick = ncread(file_name, 'icethick');
h_debris = ncread(file_name, 'h_debris');

% Define grid for plotting
[X, Y] = meshgrid(1:size(bedrock, 2), 1:size(bedrock, 1));

% Compute initial elevations
elevation_glacier = bedrock + icethick(:, :, 1);
elevation_debris = bedrock + icethick(:, :, 1) + h_debris(:, :, 1);

% Create figure
figure('Position', [100 100 1200 800]);
ax = axes;
hold(ax, 'on');
% Define colormaps
bedrock_cmap = copper(256);
glacier_cmap = winter(256);
debris_cmap = parula(256);

% Plot initial surfaces with different colormaps manually set using CData
bedrock_alpha = double(icethick(:, :, 1) == 0); % Transparent where glacier exists

% Plot bedrock
bedrock_surf = surf(ax, X, Y, bedrock, 'FaceColor', 'interp', 'FaceAlpha', 1, 'AlphaData', bedrock_alpha);
set(bedrock_surf, 'CData', bedrock, 'EdgeColor', 'none'); % Assign bedrock elevation as CData for coloring

% Plot glacier
glacier_surf = surf(ax, X, Y, elevation_glacier, 'FaceColor', 'interp', 'FaceAlpha', 1);
set(glacier_surf, 'CData', elevation_glacier, 'EdgeColor', 'none'); % Assign glacier elevation as CData for coloring

% Plot debris
debris_surf = surf(ax, X, Y, elevation_debris, 'FaceColor', 'interp', 'FaceAlpha', 1);
set(debris_surf, 'CData', elevation_debris, 'EdgeColor', 'none'); % Assign debris elevation as CData for coloring

% Set different color limits and colormaps
% Bedrock surface color limits
caxis([2000 4500]);
colormap(ax, bedrock_cmap);
% Freeze the colormap for bedrock so that changes to colormap do not affect it
freezeColors(bedrock_surf);

% Glacier surface color limits
caxis([2000 4500]);
colormap(ax, glacier_cmap);
freezeColors(glacier_surf);

% Debris surface color limits
caxis([2000 4500]);
colormap(ax, debris_cmap);
freezeColors(debris_surf);

% Add glacier mask
glacier_mask = double(icethick(:, :, 1) > 0); % Convert mask to double for coloring
glacier_mask_elev = bedrock + icethick(:, :, 1);
mask_surf = surf(ax, X, Y, glacier_mask_elev, 'FaceAlpha', 1, 'EdgeColor', 'w');
set(mask_surf, 'FaceColor', 'white'); % Set mask color to white directly
% Set transparency where elevation equals bedrock (no ice)
alpha_data = (glacier_mask_elev ~= bedrock);
set(mask_surf, 'AlphaData', alpha_data, 'FaceAlpha', 'interp');

% Add colorbars
cb1 = colorbar('Position', [0.92 0.1 0.02 0.2]);
colormap(cb1, bedrock_cmap);
title(cb1, 'Bedrock');
cb2 = colorbar('Position', [0.92 0.4 0.02 0.2]);
colormap(cb2, glacier_cmap);
title(cb2, 'Glacier');
cb3 = colorbar('Position', [0.92 0.7 0.02 0.2]);
colormap(cb3, debris_cmap);
title(cb3, 'Debris');

% Set axis properties
xlabel('X (m)');
ylabel('Y (m)');
zlabel('Elevation (m)');
set(gca, 'XDir', 'reverse', 'FontSize', 14);
title('3D View of Glacier, Debris, Bedrock, and Glacier Mask Surface');
set(gcf, 'color', 'white');

% Set view and lighting
view(45, 35);
shading interp;
camlight('left');
camlight('right');
material dull;  % Adjust material properties
lighting phong;

Answer 1

[Sumukh]

Hi @Yoni Verhaegen -WE-1718-,

Kindly refer to the following MATLAB answer to a very similar question where Adam Danz (MathWorks Staff) has provided a solution for this issue:

https://www.mathworks.com/matlabcentral/answers/2142546-plotting-two-surface-plots-in-the-same-figure-using-two-different-colormaps

The solution recommended by the staff is to use Truecolor arrays that can be applied to the various surface objects in the figure, thereby eliminating the need to assign different colormaps to axes. The colobars to distinguish the different colormaps used can still be added to the figure without affecting the surfaces. The colormaps can be converted into Truecolor arrays using the following helper function:

function tc = colormapToTruecolor(map,ZData)
% map is a n-by-3 colormap matrix
% ZData is a k-by-w matrix of ZData (or CData, I suppose)
% tc is a kxwx3 Truecolor array based on map and ZData values.
tcIdx = round(rescale(ZData,1,height(map)));
tc = reshape(map(tcIdx,:),[size(ZData),3]);
end

I hope this helps resolve the issue.