I,m replying from home, but I believe I used the grass preset from the "Fur" shelf. Then I used the "Convert paint effects to polygons" from the "Convert" menu. I'm trying to get grass to grow up through a box that has an eight bin grid. It grows up just fine but the grass blades pertrude through the sides. Using the active/passive rigid body dynamics workflow doesn't seem to be working. Although I may have missed something there. Don't think so though.