MATLAB: 3D plotted shape is not following curvature of data points

concave hull

I am writing a code that creates a 3D shape from a set of data points and am running into this problem where the shape does not properly follow the curvature of the data points and rather draws a straight line. This can be seen on the sides of the figure below where the shape isn't properly following the data points into the curves.
My code:
load('seg_info.mat');
x = seg_info(:, 1);
y = seg_info(:, 2);
z = seg_info(:, 3);
colors = seg_info(:, 4);
scatter3(x,y,z);
hold on;
DT = delaunayTriangulation(x, y, z);
[K, v] = convexHull(DT);
trisurf(K, DT.Points(:,1), DT.Points(:,2), DT.Points(:,3), ...
	'FaceAlpha', 0.5, 'EdgeColor', 'none', ...
	'CData', colors, 'FaceColor', 'interp');
Does anyone know how I can improve my code to better fit these sides? I have tried using alpha shapes and boundary in an attempt to derive the concave hull but neither worked.
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