Find better blending settings for block breaking textures

[Moondarker]

Current state:

Expected:

[Karang]

By the look of it, it seems to be a different blending mode and not simply a different oppacity. I've changed the blending mode to multiply which i think is close enough (but a bit too dark). There isn't really a way to control how much light/dark the cracks should be without editing the texture. So let me know if you consider it fixed.

[Moondarker]

Yep, it's better, but I'd like to keep the issue for now in case someone wants to further improve it :) Might even try it myself later, gotta get familiar with three.js