Hi NF, There are a several things to watch for. First, don't duplicate Surface Replicators. Just insert new ones. You can make duplicates work but it's sometimes problematic - it's just easier on the system to insert a new one. Secondly, try reducing the minimum distance to zero instead of the default 1.00. Especially for grass and flowers, you don't have to worry about them overlapping. Finally, make sure the quantities are different and enable clumping for organics like grass and flowers. It just makes a little more believable irregularity. Mark