Merging two tetrahedron meshes

[tmedani]

Hi @Kevin-Mattheus-Moerman & all,

I'm wondering if there is any function that allows the merging of two tetrahedral volumes.
For example, I want to merge a rectangular prism inside a sphere, where both are represented as tetrahedral meshes.

I can't use the surfaces since the rectangle has 2 different materials as shown in the figure.

Is there any function in Gibbons that can handle it, any help or orientation is welcome.

Thank you.