Allow canvas cubes (and other shapes) to use transparent textures

[Niz]

Titles pretty self explanatory. One of the first things I wanted to make with the cube was minecraft glass and ice blocks, so I was immediately disappointed that it wasn’t going to work.

[Radek]

Transparency not a thing on canvas blocks?
That’s not just a missing feature. That’s a crime.

[macdguy]

It will be added later.