void Client::setCrack(int level, v3s16 pos)
{
	int old_crack_level = m_crack_level;
	v3s16 old_crack_pos = m_crack_pos;

	m_crack_level = level;
	m_crack_pos = pos;

	if(old_crack_level >= 0 && (level < 0 || pos != old_crack_pos))
	{
		// remove old crack
		addUpdateMeshTaskForNode(old_crack_pos, false, true);
	}
	if(level >= 0 && (old_crack_level < 0 || pos != old_crack_pos))
	{
		// add new crack
		addUpdateMeshTaskForNode(pos, false, true);
	}
}