R, how can I plot two functions in one 3d plot? (I show an example)

Question

Do someone know how to plot two functions in one 3d plot using R as in the left-figure or right-figure shown below? (article reference at the end).

3d plot

For example, in 2d plot you have the argument "add" for the function curve(...)

For what I have searched, the functions I have found (like persp(...)) doesn't have an "add" option.

Thanks!

Reference: Juan M. Astorga, Yuri A. Iriarte, Héctor W. Gómez & Heleno Bolfarine (2019): Modified slashed generalized exponential distribution, Communications in Statistics - Theory and Methods, DOI: 10.1080/03610926.2019.1604959

Answer 1

I already found a function which works perfect for what I need. If anyone are interested, persp3D(...)

https://www.rdocumentation.org/packages/plot3D/versions/1.3/topics/3-D%20perspectives