Here's what I've been trying to do. Use Pflow to plant a large number of 2D 'cards' on to a surface, which face the camera. I'm doing a forest.
I have a 'position object' and a 'shape facing' in the first event (there is only one event).
I have chosen the landscape as the emitter source in the position object, by surface. I have chosen the camera in the shape facing.
How on earth do I actually get a card or a rectangular shape on which to apply a tree texture with an opacity map? How do I change the size of said shape also?