Question

I tried to use VTK library from C++.

Is there any example of using VTK just to plot simple 3D contour graph like the one shown below?

The official VTK Wiki has dozens of code examples, but I cannot find any useful example of this simple task.

Answer 1

A while back I wanted to do the very same thing and did some extensive searching. It didn’t turn up much so I want to share with you my solution. It contains some superfluous code but it works. http://pastie.org/4721543

I just rediscovered this question because VTK 6.0 will have a plotsurface function. Which most likely will be far more performant than what my code does. I will try it later and update this post.

A little explanation to my code might be helpful though. It does the following:

1. generate a plane the size of your 2D matrix that holds your z values (cols & rows represent the x & y values).
2. create xyz-points from the input matrix
3. store the z values as scalars for each point
4. warp that plane according to the z values of the matrix and apply colors (mapper->SetScalarRange(..)
5. draw your plot

It also adds a timer and an update command, it outputs rendering statistics, etc. as I said there’s much you can leave out. My blog post elaborates a little bit more on this, but not much.