bool GetCurContactGeom(int index, ref d.ContactGeom newcontactgeom)
{
if (ContactgeomsArray == IntPtr.Zero || index >= contactsPerCollision)
return false;
IntPtr contactptr = new IntPtr(ContactgeomsArray.ToInt64() + (index*d.ContactGeom.unmanagedSizeOf));
newcontactgeom = (d.ContactGeom) Marshal.PtrToStructure(contactptr, typeof (d.ContactGeom));
return true;
}