How to set the transparency of model

[xmyykj]

Is there a way to set the transparency of the structure like this.

this function is very important for anatomy.

[ultr4m4n]

I believe we can achieve this by using materials.opacity . Question is how do we fetch the materials to update?

[yvanblanchard]

I would also be very interested ; in mechanical engineering, working with assemblies with housing/fairing parts containing lots of other parts, it's very useful.