Problem with the weight paint mode when there are a lot of geometry on the mesh I have some problem with the weight painting of the mesh,check the attached video and tell me please what's the correct way to operate,in this case. Since there are a lot of geometries on the mesh,I suspect that I need to use the face/vertex selection masking for painting,but I don't know how.

demonstration video

screenshots :






NB : I also tried to use the vertex selection masking and you can see in the video below that it didn't work...

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in Weight Paint mode press M or V to enable Face or Vertice selection masking (you will notice one of the button at the bottom of 3D View will get pressed). after this you can either use simplified selection tools in Weight Paint mode itself or go to Edit mode to use a full specter of selection tools there and then return back to Weight Paint mode with your selection preserved between modes.