Cloth simulation - simulate 2 unlinked meshes together as one Gentlemen, I have a problem with the cloth simulation. The object I am simulating consists of 2 or more parts that are not interconnected. As a result, the simulation treats them as two separate objects.

How can I make them behave as a single one?

For example: I am modeling the German flag. It has 3 rectangular parts (Black, Red, Yellow). And the sews have stitches (which is another separate object).

Now, I want the entire flag to fall onto something but all these individual pieces don't interact as one. What is the solution? Do I need to merge it somehow? (If so, how? Boolean operations...?)
Let's assume the stitches or other details can be represented by some cubes close to the flag geometry.



Duplicate the Flag mesh. The FlagDupe should also do the same simulation as the original. We will create a cage from it for the extras.

Add a displace modifier, and a solidify modifier. The value of the second modifier should be twice the value of the first modifier.



Select the stitched extra object, add a MeshCage Modifier to them and bind the object to the FlagDupe by clicking on the bind button.



The bound object will follow the FlageDupe object.