I need to apply weight paint manually, because the automatic weights method failed. How do I select which bone I want to apply the weight paint to?
1 Answer
There are at least two ways to do this. The way weight painting connects bones to the mesh is through vertex groups. The vertex group that has the weights for a bone has the same name as the bone. So, you can ignore the armature, and simply select the appropriate vertex group in the properties editor.
Or, you can go to object mode, select the armature, shift select the mesh, and enter weight paint mode. In weight paint mode, you can hold Shift while left clicking on a bone to select that bone.
Here's a cube that I've subdivided into three segments. There's also an armature that I've parented the cube to with empty groups:
Notice that I've turned on names in the armature's Viewport Display properties.
As you can see from the Cube's Object Data Properties, there is one vertex group for each bone:
In this screen shot I have the top
vertex group selected. If I enter weight paint mode and start painting, I'll be influencing the top
bone. In weight paint mode I can shift between vertex groups by clicking on them in the Vertex Groups panel.
If I want to use the other technique it helps to turn on In Front in the armature's Viewport Display panel. Here I've shift left clicked on the center
bone. You can see it outlined in blue to indicate I selected it: