3D plot surface

Hello ! I am working on a project that uses ultrasonic sensors to map objects in a room. The module is traveling in a straight line in the middle of a rooom at different altitudes and picking up objects closest to it . I am recording the date in vectors x(module movement) , y(sensor measurements) and z the module altitude. The picture shown illustrates a large object at 40cm floor level and another above it at 100cm between the module flight path and the wall.

I have used plot3 to create this 3d plot and its working fine although the quality will be improved . Is there any way to create a surface over all the points that would have been seen if loooking from the x axis ? I am trying to actually show the objects without the points. I have tried using mesh and other methods found on the matlab help pages but with no luck.

Any help would be much appriated :)

Answer 1

[Sam Chak]

Hi @GibonCZ

The best is the provide a small sample of the spatial data for testing. Otherwise, the function surf can be used to create a surface plot. See the following example:

[x, y] = meshgrid(-pi:0.15:pi, -pi:0.15:pi);
z = (tanh(x - 1) + tanh(x + 1))/2 + ((tanh(x - 1) - tanh(x + 1))/2).*sign(y);
surf(x, y, z)

[GibonCZ]

Thank you Sam for getting back to me ! I am attaching the sample vectors that I am working with ( x,y,z) this is a small scan area of approximatly 1 m width and 40 cm height with two objects (boxes) in the view. All zero values were replaced with NaN with x(x==0) = NaN command.

Figure explanation - the scanning was performed at 3 differents heights with the first points at +- 120 being the wall , second at 60 being the first object and then 3rd object following at the right side of the plot.

I have tried surf function Z = meshgrid(z) , surf (x,y,Z) and this is what Im getting

Its getting closer but not quite there :) I would like for all the points to be joined together, creating a surface that can be seen from the x axis (0-100axis) so the objects can resemble the original ones. Also for some reason the points were duplicated and more were added to the graph , possibly because of the meshgrid. Any ideas for improvements ?