How can I smooth 'trisurf' surface-plot?

How can I smooth the surface generated by 'trisurf' command?

To create a surface from some scattered data, I use the method suggested here:

% initially, x, y, z are coordinates of scattered data
x = scatteredValuesX;
y = scatteredValuesY;
z = scatteredValuesZ;

% to create a surface from the scattered data, a triangulation is used
% this method is suggested here: https://au.mathworks.com/matlabcentral/fileexchange/5105-making-surface-plots-from-scatter-data
tri = delaunay(x,y);
trisurf(tri, x, y, z);

The result is very noisy and I would like to smooth the surface, but I have not yet discovered the way of how to achieve this goal.

I have found a function 'smoothn' here which could potentially achieve what I need, but I am not sure if it is possible to adapt my data in order to feed this function properly.

Any input would be appreciated.

Answer 1

[Satwik]

Hi,

Here is workflow using which surface smoothening can be achieved for data plotted with 'trisurf', using 'smoothn':

1) Interpolation onto a grid: The scattered data are first interpolated onto a regular grid, which allows 'smoothn' to be used

% Define a grid
[xq, yq] = meshgrid(linspace(min(x),max(x),100), linspace(min(y),max(y),100));

% Interpolate scattered data onto the grid
zq = griddata(x, y, z, xq, yq, 'natural');

2. Smoothing the Surface:

zq_smooth = smoothn(zq); % 'smoothn' is available from the File Exchange

3. Plotting the Smoothed Surface: The smoothed surface is plotted with 'surf', not 'trisurf', since the data are now on a grid.

surf(xq, yq, zq_smooth, 'EdgeColor', 'none');
view(3); axis tight;

I hope this helps!