Hi Houdini friends, Does anyone know how to use mask field in DOP net? I'm doing a simulation of leaves on the ground reacting to a car passing by. I need to control the wind force to affect only where the car is passing, where other leaves remains more still. Is there any way to mask out the affected area and have the wind force only affect that area and have dynamic change on the mask object? Or if there's other ways to do this? Thank you so much!!!