https://sims4studio.com/thread/9822/mini-tutorial-easy-weight-assigment

This is the final part which will show you how to assign breast bone : b__CAS_L_Breast__ for the left and b__CAS_R_Breast__ for the right.

>> this tutorial will show you how to make hair fits with larger/smaller breast size <<

Now let ‘s start

1. Change into

Wireframe mode

(1 - 2 )

2. Add a new vertex group and change to left view ( 3 - 4 )

3. Use

Weight Gradient

and draw a linear color like the picture, I usually make it end at the shoulders. Remember changing to

Weight Paint mode

first. ( 5 - 6 )

4. Now change to

Edit Mode