Connection with the ground -> solid figure

How can i create solid figure that is connected with the ground so it would like a cutted cube? Just the connection with the ground.. i am new to this.

[Ted Shultz]

Do you just want a picture of this, or would you like to use this 3d object for something?

[Jan Nabo]

no, later i want to convert this into a 3D-printing file and print that solid out

[Jan Nabo]

i want to use this 3D-Object to print this out*

Answer 1

[Chidvi Modala]

‘surf2solid’ takes a surface and converts it into a solid.

You can refer to https://www.mathworks.com/matlabcentral/fileexchange/42876-surf2solid-make-a-solid-volume-from-a-surface-for-3d-printing