@Natanox Hi! Yeah it's pretty much the same as that! In general it's good to have as few unique materials as you can, so if I was setting different transparency on different objects I would end up with lots of unique materials. This way the transparency is stored in the surface's vertex data and I only have two unique materials in the project, one for opaque objects and one for transparent ones.
This *may* be premature optimization, but I would like the game to run nicely on low-end hardware!