I made a mini tutorial for those struggling with assigning joints in Sims. I specifically made this for a individual who asked about it on a tutorial made by someone else on youtube but thought it would be helpful for anyone having trouble with this step so I decided to post it here.
Assigning joints is a critical basic step that is important to learn. Failure to assign joints will result in the object appearing transparent in game, so if this is your issue, likely you did not assign the joints.
Please comment if you need any further clarification and I will be happy to assist you.
Lady Aliah Designs