Hello!.. I have a plan, with a black and white texture… do deform this plan, I want to use the texture as a stencil, but, if I “go” via "make alpha- then alpha make stencil, the resulting stencil has moved, and it is tedious to match exactly the texture, with scaling and rotating… How to use simply the black and white texture as a stencil, without re -positionning it?.. thank you!
Have you tried Spotlight?
Marcel,
Perhaps you can apply the texture on the mesh, then convert it as a Polypainting, then as a Mask and do your sculpting?
You should post some screenshot to help us understand better your problem 
Even with the texture simply applied to the mesh you can use something like Tool>Masking>Mask by Intensity to convert the texture data into a mask. Then turn off the texture and sculpt or deform through the mask.