Map object shape to internal of another object

Hi folks. I’m struggling to find the best way to achieve creating an object to fit the internal space of another.

for example, this isn’t the actual result required but the easiest to explain I can think of.

A glass of water, modelling the glass is no problem, but how would it be best to then model the water inside. Applying the textures isn’t a problem, I’ve got that sorted, it’s just mapping the object.

I’ve been messing about with the Boolean modifier, which for no particular reason seems a reasonable place to start, but can’t find a combination of settings that works.

All help appreciated.


Not sure what you mean by “mapping the object”. However, for your water glass example I would…
a) select the inner faces of the glass up to the water line,
b) Shift-D to duplicate that faces and P to separate them into a new object,
c) add the top surface to the water mesh, make sure the normals are correctly aligned and finally
d) scale the water mesh up a little so that it intersects the glass mesh ever so slightly (to avoid shading artifacts).

Yeah, I know that some IOR purists will complain that this might not be 100% physically correct, but the result is highly appealing and the difference to a “perfect” IOR solution is - imho - not visible.

Thanks Ikari, I hadn’t thought of that approach. It will certainly do for the result I’m after.

Many thanks. :o)