Whenever you're doing 3D measurements, you might get in trouble when there are obstacles blocking your view.
You want to measure a stockpile, but a conveyor belt 🚧 is in your way. You're determining the surface length of a road, but you forgot to move your car 🚗 . You want to measure how much earth you have to move, but a tree 🌳 is blocking your view.
Fear not! Surface Cleanup will help you all in those cases! ⛏
To show you how it works, we'll take a look at the first example: removing a conveyor belt to enable accurate stockpile measurements.
Rather watch a video? Check out this article.
1️⃣ The problem
Before we start explaining the solution, let's first take a look at what the problem looks like. You want to measure the volume of a stockpile, but a conveyor belt is hanging over it. This means the volume between the stockpile and the conveyor belt is included in the result, which is not what you're interested in of course!
2️⃣ The solution
With Surface Cleanup, the solution is rather simple. You'll create an annotation around the conveyor belt to mask it out. You can create a polygon annotation using the Annotate/Measure menu:
Go ahead and draw a polygon around the conveyor belt as follows:
Give a name to the annotation and enable the Surface Cleanup tool:
Save the annotation and voila! 🎉 The conveyor belt is no longer a problem! When you do the stockpile measurement again, the volume is correctly calculated.
3️⃣ How it works
When looking at the active Surface Cleanup box in the annotation popup, you might have noticed two pieces of information:
Target Surface: This is the surface on which the cleanup will be applied. For now, we only support a single DSM, but that will change in the future. 😉
Surface Type: This is the type of surface that will be used as a replacement. For now, we only support an interpolated replacement surface. In the future, we'll add the other types you already know from the volume measurements.
The Surface Type is the important part here. It determines how we actually clean up the surface. For now, we only support an interpolated replacement surface. This means we try to mimic the surface by looking at the elevation on the vertices of the polygon that you drew. Adding more points to your polygon will thus allow us to smoothen the surface even more. Placing the points on specific edges will also allow the replacement surface to follow those edges better. In this example, you might want to place two points on the edge of the stockpile to make sure we don't cut off the corners there.
4️⃣ Tips & Tricks
The surface cleanup will linearly interpolate between the points you draw. This means it's drawing straight lines between the points you draw to replace the surface. When the surface curves a lot, it's best to place more points, so the surface cleanup will follow the surface better.
Surface cleanups work for all types of 3D measurements, so surface lengths or elevation profiles will also use them.
The digital surface model you can download from the Layer Downloads pane doesn't include surface cleanups. It's the original model.