Merge code , glass material on imported mesh

Questions
1

hey Guys,
i have been trying to use the skull.babylon mesh from here :
https://www.babylonjs-playground.com/?fbclid=IwAR2VMpGV0jyjMYnTTP0xLUL5nJUiP2Rfr31wRwU6CPIenTBhzNjq2v6WZeY#UKNERM#0
to replace the sphere from this code aka ( having the skull in glass):
https://www.babylonjs-playground.com/?fbclid=IwAR2VMpGV0jyjMYnTTP0xLUL5nJUiP2Rfr31wRwU6CPIenTBhzNjq2v6WZeY#19JGPR#13

any pointers to what i am missing?

thanks

2

Hey!

something like that?
https://www.babylonjs-playground.com/#19JGPR#56