Custom Block Break "Overlay"

[FireTamer81]

What is the block breaking animation, and how could I do something similar? 

Rather than cracks forming from center to edge, I was wanting to make it just change opacity so the "intensity" of the cracks just gets worse. I am doing this for my "Strong Blocks", but since I am going to have somewhere around 48+ total, I don't want to make 240 textures (5 crack levels each).

So, is the vanilla animation just a texture rendered over another, is it the original block texture being combined with the various stages of the break texture (a + b1, a +b2, etc), or something else?

I also want to avoid just replacing the vanilla break animation itself since I want this "overlay" to stick around rather than just when the player is breaking the block. (if so much damage is taken up until it gets to say "crack_texture_3", it won't go away unless repaired or damaged further)

[FireTamer81]

Sorry for not replying until now, had some stuff to deal with.

From what I understand, wouldn't this only draw the "overlay" when the block is hovered over by the cursor? If so then perhaps a grass block would be a better example. I think it has two layers, one for the dirt, and another for the monochrome grass that has it's color changed dynamically. 

I'll look through what you said first, and then the grass block if your thing doesn't work. Thanks though

[FireTamer81]

Hmm, I might just do some sort of jimmy rig to get around this.

Do something like make a block model in blockbench that is slightly large than a normal block (something like 0.01 on each side to prevent z-fighting), draw the textures and just have the blocks act as a multipart. (I really hope this can end up transparent and not just blackout the texture underneath)

Might be messy, but I really just want to get this done to move onto something else (been working on this one feature for maybe a month because IRL stuff).

Thanks for the suggestions anyways mate (I can probably use them for some other crazy idea later).

[Draco18s]

If you want a tiny fraction of offset, use float.epsilon.

0.01 will actually be noticeable. It's about 1/6th of a texture pixel.