How can I transfer a boneless shirt to an rigged body with skeleton?

I have a 3D character and a shirt that has no bones of its own.
the boneless shirt should be made on the character. but because the character already has bones, the shirt should copy the weighting data of the existing character.
but how does it work?
I have been trying for 6 hours without success and felt half searched YOutube in the Blender area …
How can I only connect this simple shirt to my existing character?
Under the shirt is a naked body from which the shirt should then take the mesh transfer data …
But how?

I’m sure there’s a way using the data transfer modifier, but I’m usually using this free addon here.

It’s super easy, convenient, and does the job well.

As dan2 mentioned… you can use the Data Transfer Modifier:

On your Shirt Object:

  1. add the modifier Data Transfer (make it 1st in the Stack)
  2. Check Vertex Data
  3. Check Vertex Group(s)
  4. Source Object the Body Object (rigged mesh body)
  5. Click on Generate Data Layers
  6. Apply the modifier
  7. parent the shirt onto the armature selecting “…Empty Groups”

make sure that your armature is in resting position and that the armature and body object is in 0,0,0 location and unscaled (meaning scaling 1:1)