When working with Virtual Surveyor, you may notice a certain tools taking longer than normal. A common cause of this can be the spatiality of your boundary item(s).

The shape and vertices density of a boundary can influence Virtual Surveyor's processing performance. The most affected workflows are Cut/Fill maps, Volume Calculation and Export. The simpler a boundary, the better the software will perform.

In this article, we compare the processing performances between simple boundary and complex boundary using the same Virtual Surveyor tools.

## Cut/Fill map

We will analyze the time to produce a Cut/Fill map using two similar boundaries. The boundaries have the same 2D shape. The complex boundary has been densified with a point every 10ft.

Simple boundaryComplex boundary
Boundary area28.1 acre28.1 acre
Boundary 3D length6004 ft8071 ft
# vertices62632
Computation time3.4 sec13.2 sec

In that case, there is absolutely no value the use a very dense boundary.  The boundary is only used to defined the area of interest. The cut/fill results are exactly the same.

## Volume calculation

We perform the same exercise when calculating the volume of a stockpile. The boundaries have the same 2D shape. The complex boundary has been regularly densified at 0.5m.

Simple boundaryComplex boundary
Boundary area1192 m2 1192 m2
Boundary 3D length131.5 m132.7 m
# vertices30277
Computation time0.95 sec2.14 sec

For stockpile volumes, you need to assess the boundary density while considering the refence surface accuracy. Remember, the boundary is used to create that surface. If you utilize too simple a boundary, the reference surface can be inaccurate, leading to a miscalculation of the volume results.

## Export

More important than the number of vertices, the shape of a boundary has a significant influence on the performance of image and elevation exports. These two boundaries cover approximately the same area. The Yellow boundary has a larger 2D surface, but a simpler shape.

Simple boundaryComplex boundary
Boundary area18371 m215331 m2
Boundary 3D length638 m661m
# vertices1288
Export Image time23.3 sec41.3 sec
Export Elevation time12.0 sec29.1 sec

To maintain quick exporting performance, try to use the simplest boundary possible. Even if the simple boundary covers a larger 2D area, the export is generally two times quicker.