I have a set of point cloud with this format:

```
x = [1.2, 1.3, .....]
y = [2.1, 1.2, .....]
z = [0.5, 0.8, .....]

```

And I use `plot_trisurf` to plot(by Delauney triangulation) a 3D surface that "represents" the point cloud.

My question is: is there a quick/decent method to project the surface generated by `plot_trisurf` to xy plane and only plot the outline of the projection as a 2D plot?

For example, suppose all my points in the point cloud are on a sphere surface, then `plot_trisurf` will plot a (not-that-perfect) sphere for me. Then my target is to "project" this sphere to xy plane and then draw its outline as **2D** plot(which is a circle). 

Edit:

Kindly note that this **2D**
 plot is a 2D curve(possibly closed curve).