How to weld a model with multiple parts to a players character?

Have been seeing a lot of tutorials on how to weld singular parts onto the player via weld constraints, what about a whole model?


I have build a little backpack with multiple parts and I struggle to weld it onto the starter character. Using a weldconstraint, a1 = torso, a2 = primary part of the model results in chaos since every other part in the model is unanchored/ not welded. Are there any elegant methods?

Off-topic question:
I have also created an animation where the player grabs this backpack, puts it on the ground and opens it when a specific key is grabbed. If the backpack is welded to the player, how would i make it temporarily invisible during the animation? Or how would I be able to animate the backpack on the player since colors, materials of it will be customizable in game? My goal would be to animate the selected, welded backpack on the player itself.

Best regards!

You need to weld all the parts inside the backpack model to the backpack’s primary part. Then, you can weld the backpack’s primary part to the character’s torso.

Is there an easier way? Will too many welds create performance issues, since every player will eventually have one backpack?

Eventually, the number of welds could cause performance issues, but that typically only becomes a problem once you reach thousands of them.

If you’re looking to optimize the backpack further, consider using Unions or simply reducing the overall part count to improve performance.

Weld unanimatable parts with WeldConstraint and for animatable part use Motor6D
Highly suggest to turn it into a mesh,bake texture in blender and reimport aswell set ColisionFidelity to box

It should same a lot of perfomance and be easier to manage without having to have million welds.

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I followed Owl’s advice and managed to make the backpack 3 unions only. That way the backpack is still customizable in colors and texture, for example if i add that as an option in a shop. Now when I press I (Inspect backpack) I would want to play an animation where the player grabs its backpack and places it on the ground. In theory, could I use that now welded backpack model and animate it via Roblox Editor/ Moon Animator 2? I have only animated walking animations for now and I have no experience if it is even possible to animate a backpack opening :slight_smile:

Don’t use unions.
export each part (union) as obj/fbx and reimport
Union keeps a lot of (bloatware) unneeded data that slow down perfomance.

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And afterwards I can animate this? I do not even know if it is possible to have one animation instance which animates parts ^^