MeshCollider.smoothSphereCollisions
var smoothSphereCollisions: bool;
bool smoothSphereCollisions;
smoothSphereCollisions as bool
Description

Uses interpolated normals for sphere collisions instead of flat polygonal normals.

This smoothes out bumps for sphere's rolling over smooth surfaces. The downside is that rolling over steep corners can behave really strangely and appears like it is pulling the sphere in some direction.
	transform.collider.smoothSphereCollisions = true;
using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour {
    void Example() {
        transform.collider.smoothSphereCollisions = true;
    }
}
import UnityEngine
import System.Collections

public class Example(MonoBehaviour):

	def Example() as void:
		transform.collider.smoothSphereCollisions = true