I am looking for additional alpha "texture paint" brushes online. I keep finding various Brush packs - but they all seem to be sculpting brushes.
Can alpha images for texture paint and sculpting brushes be used interchangeably? (i.e. it's actually the same type of alpha image - it just does different things when it's a sculpting brush (raise geometry in the white parts of the mask) versus a texture paint brush (add or remove color in the white parts of the mask?)
If they are not the same, how do I know if the alpha is for sculpting or texture painting if it doesn't specify in the brush pack's description (i.e. are there differences in the files themselves that can be seen)?
Also - what else goes into a brush besides the alpha? (I saw a sculpting brush set that said it could be used in both ZBrush and Blender. Do all ZBrush sculpting brushes work in Blender? I would assume that's not the case, but I'm very confused). Also, are Photoshop, MyPaint, Krita, etc brushes just alphas? I assume not - but if they are, could those alphas be used with Blende's texture paint? Could the whole brush be used? (I'm virtually certain this isn't the case, but I don't know))?
Are there any good resources for learning exactly how brushes work, how alphas are used in them, and even perhaps how brush formats differ between Blender and other pieces of software? (If such a resource exists, I'm fine if it gets technical into file format details and all).
Thanks
"Can alpha images for texture paint and sculpting brushes be used interchangeably? (i.e. it's actually the same type of alpha image - it just does different things when it's a sculpting brush (raise geometry in the white parts of the mask) versus a texture paint brush (add or remove color in the white parts of the mask?) "
As far as I know, yes.
Suppose you have a piece of plastic, like this:
Now, you can put this on some paper and spray paint over it, basically using it as a mask. Or use oil paint, or water paint, all using the same 'mask'. you could put clay over it and when you remove it, it would leave only clay where the holes are, my, you might even use it to shape cookies.
This piece of plastic is your texture and this is probably where the name Alpha comes from (although the alpha textures in CG are greyscale and not just black and white, but the idea is the same). Whether you use them for Sculpting or Texture Painting is your decision.
So, yes, you can use Sculpting Alphas (or Textures) for Texture Painting. They are not actually Brushes, just greyscale images.
Now, Krita Brushes are files that have more information; not only the texture, but also what kind of brush (spray paint, pencil, chalk, etc.)
(and probably some default settings, like strength, fall-off, etc.).
I don't know about Photoshop or ZBrush (or MyPaint) brushes, but when it says it's for ZBrush and Blender, it will not be a brush, but just a Texture (sometimes called Alpha).
As for resources, there is not (afaik) a single source that explains different brushes for different software, but I can recommend the Krita Manual.