Multi variable functions
Another problem I found when trying to export to STL and 3D print was that the functions ended up being zero-thickness objects so they do not appeared in the STL files.
For example the function that you see below does not appears in the STL export.
f(x,y)=x^2+y
![f(x,y)=x^2+y](https://www.geogebra.org/resource/gwp4spgb/DtsvEgeQKME8OGgR/material-gwp4spgb.png)
![Image](https://www.geogebra.org/resource/kbcffcbj/bQcalHnwCZ6R4BDh/material-kbcffcbj.png)
Solution:
This was also solved with a little trick:
We are going to create a simple parametric curve and once again with the surface command we will be able to create a surface that appears in the STL export.
We are going to treat our function as parametric curve using the parametrization: and the surface command:
Surface(r , t, f(r,t) , r , -2 , 2 , t , -2 , 2) Getting the following STL export:
![Image](https://www.geogebra.org/resource/ts8gwspu/fvcM5XMeiCFGovcD/material-ts8gwspu.png)