When working in Virtual Surveyor, you may notice that certain tools take longer than to process information. 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 a simple boundary and complex boundary using the same Virtual Surveyor tools.

## Cut/Fill map

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

Simple boundary | Complex boundary | |
---|---|---|

Boundary area | 28.1 acre | 28.1 acre |

Boundary 3D length | 6004 ft | 8071 ft |

# vertices | 62 | 632 |

Computation time | 3.4 sec | 13.2 sec |

In this use case, there is absolutely no value in using a very complex boundary. The boundary is only used to define the area of interest; the cut/fill results are exactly the same.

## Volume calculation

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

Simple boundary | Complex boundary | |
---|---|---|

Boundary area | 1192 m2 | 1192 m2 |

Boundary 3D length | 131.5 m | 132.7 m |

# vertices | 30 | 277 |

Computation time | 0.95 sec | 2.14 sec |

For stockpile volumes, you need to assess the boundary density while considering the reference surface accuracy. Remember, the boundary is used to create that surface. If your boundary is too simple, the reference surface can be inaccurate, which leads 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 are approximately the same area, except the Yellow boundary has a larger 2D surface with a simpler shape.

Simple boundary | Complex boundary | |
---|---|---|

Boundary area | 18371 m2 | 15331 m2 |

Boundary 3D length | 638 m | 661m |

# vertices | 12 | 88 |

Export Image time | 23.3 sec | 41.3 sec |

Export Elevation time | 12.0 sec | 29.1 sec |

To maintain a faster exporting performance, try using the simplest boundary as possible. Even if the simple boundary covers a larger 2D area, the export is generally two times faster to process.