Hello,

My friend and I have been working on an object and we want some parts to be
transparent. In Milkshape you can make objects transparent, but when you save and then import it with Wings 3D it is solid.

Will it be transparent when I play Sims 2? I haven't got it installed on my computer and only made the mesh for it.

Transparency in sims2 objects is controlled by the TXMT. You will want to assign the transparent parts to one group and the solid (not transparent) parts to a second group. Pixelhate has done a definitive description of the TXMT parameters.

Just looking at the grid in the background, you have a lot of scaling smaller to do.