I have been putting some time into getting the grass into the world and then cutting it down. One of the details I found to be necessary was actually cutting where a lawn mower’s blades would be. Here I have a dune buggy, so not quite a zero turn, but I found what I thought would be a reasonably expected area to cut. The red lines forming the tipi are traces to the grass underneath you and will remove any grass that this line collides with. I found that I didn’t need to check the whole circumference because the actual hit box on the grass is a fairly well encapsulated rectangle. It wouldn’t be possible to slip underneath you without getting hit. That said, it might still over cut as a result.
