Laying image over 3-D surface

I have a 3-D on which surface I'd like to lay an image "on top." The specific surface I have is created from the variable new, which is a 960 x 1280 matrix:

ax = mesh(new);
ax.XLim = [0 1280]; 
ax.YLim = [0 960]; 
box on
view(-37.5,-30);

This plot is viewed from an elevation of -30 degrees. I want to overlay a 2-D image so that when the image is viewed in regular 2-D Cartesian space, its warp gives the effect that the image is "falling in" to the sharp minimum on the surface. What's the best way to do this? Thank you!

Answer 1

[Walter Roberson]

https://www.mathworks.com/help/images/ref/warp.html

[ohmstead]

Getting an error with warp that I'm not sure how to fix.

>> [image,colorMap] = imread('forest.tif');
>> [X,Y] = meshgrid(1:960,1:1280);
>> ax = warp(X,Y,new,image,colorMap);
Warning: Error creating or updating Surface
Error in value of property  ZData
Array is wrong shape or size

>> size(new)
ans =
       960        1280

[Walter Roberson]

Whatever your new is, it is not 1280 x 960. Is it perhaps 960 x 1280? Watch out: rows correspond to Y values, not to X values.

[ohmstead]

I got it working; the image looks like so:

However, when looking down on it, as I stated in my original question, I would like it to reflect the warp somehow. It does not do this when I set the view using view(0,90), as is shown in the second image:

Do you know of a good way to make it look like I'm "stretching" the image when looking down on it orthogonally?

[Walter Roberson]

You could try

pcolor(X, Y, image)

By the way, we recommend against using image as the name of a variable, as it is the name of the fundamental MATLAB function for displaying images, which leads to confusion and bugs.

[ohmstead]

Thanks for the tip! Changed the variable name.

No luck with pcolor.

[Walter Roberson]

Could you post your complete code (in particular how you create new) so I can do some testing? I know what the basic problem is, but I need some test data to try out ideas.

The basic problem is that you are using rectangular pixels in a uniform rectangular grid, and the default lighting model is that the brightness and color of a pixel does not depend upon the depth from the viewer. You either need to move to using X Y that are not uniform rectangular, or else to make changes so that the brightness chances according to depth.