Combining the falloff sop with a few groups is a great way to control attributes by distance without having to jump into VEX and VOPs. A lot of sop nodes output groups along with the operations they do so I figure you might as well use them when you have the chance. Here are a few examples of the falloff sop in action.
I had to build a custom fracture setup for a job based on getting a specific look. I was using The Voronoi Fracture sop and I wanted a controllable distance from edge where the inside and outside meet. The Voronoi Fracture sop outputs an inside and outside group and with a bit of group compositing I could find the edge and use the falloff sop from their to create my distance from edge attribute.
![](https://zybrand.xyz/wp-content/uploads/2019/05/falloff_from_edge_01.gif)
Another use is to create a distance attribute from the border of an object with unshared edges. I used the falloff node in this way as a quick base attribute to create a lake with depth from a flat grid.
![](https://zybrand.xyz/wp-content/uploads/2019/05/falloff_from_edge_02.gif)
You could flip that around and create a mountain peck as well by adding to @P.y instead of subtracting. Which could be used as a way to hand sculpt base shapes for driving the terrain tools. So far I have been using the Surface Distance mode as the distance metric in first two examples but if we switch the distance metric to edge we get a result that looks like some erosion has happened which is great for making mountains.
![](https://zybrand.xyz/wp-content/uploads/2019/05/falloff_mountain-1024x600.jpg)
The reason for the vein like uneven appearance of the distance is because of how edge distance is accumulated. Like the Edge Transport sop the distance from a point to the goal point is counted up by travelling along the shortest possible path along the edges to the goal point. So the distance from point A to point B depends on the edge flow of the topology which create the variation and vein like appearance on a poly mesh.
Edge Distance Surface Distance