I sculpt, apply mask to work on a difficult area, then every brush stroke I do results in broken mesh. Disabling mask don’t help. Neither is deleting multires and starting over. The whole project file is borked now.
On this screenshot this is me applying elastic deform on character hand. It picks random bits it wants to move, holds the rest in place and destroys the model.
I know this sounds like a troll, but the simple answer is don’t use Multires.
I don’t think it’s the masking or the normal problem. It’s Multires problem. It’s buggy since day one and it doesn’t seem to be fixed anytime soon. I had spikes all over the place when I was using Multires, and it was almost two years ago.
Just use a normal subdivision, apply it, and then sculpt it from there. Then repeat for the subsequent subdivision level.
How many faces do you have on your model? I guess it very much depends on your machine.
But speaking from experience, I have a 120k-faces 3D model, fully rigged, and I have never experience any slowness in Pose Mode (unless I turn on some Physics like Collision), and I can easily get 24 fps animation.
And yeah. it works except a very few certain things. If it’s acceptable, then well, Multires is a fine choice. But if it’s not acceptable, like myself who expects things to work all the time and not most of the time, then I’d invite you to join the club and stop using Multires.