Scripting Reference
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SkinnedCloth.worldVelocityScale

var worldVelocityScale : float

Description

How much world-space movement of the character will affect cloth vertices.

The higher this value is, the more the cloth will move as a reaction to world space movement of the GameObject. Basically, this defines the air friction of the SkinnedCloth.

JavaScript 
    GetComponent(SkinnedCloth).worldVelocityScale = 0.5;
using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
    void Example() {
        GetComponent<SkinnedCloth>().worldVelocityScale = 0.5F;
    }
}
import UnityEngine
import System.Collections

class example(MonoBehaviour):

    def Example():
        GetComponent[of SkinnedCloth]().worldVelocityScale = 0.5F