Add automatic weights to specific bones

Question

I have a model that has already been rigged, but is missing weights for a few bones. I would like to be able to use the automatic weight system to add in the weights for these bones. However, since the model has vertex groups already, parenting with automatic weights would mess up the already made weights. How can I add automatic weights to the missing bones while preserving the already made weights?

Answer 1

Select your armature, shift select the mesh object, switch to Weight Paint mode, select the bone you want with left click, select more bones with shift left click, go into the top bar > Weights > Assign Automatic from Bones: