3Dメッシュでの体積測定の描画

Question

私はまだSiteScanを使ってドローン飛行から体積を抽出することに慣れていませんが、処理済みの飛行の3Dメッシュタブで体積測定を行う方法があるかどうか知りたいです。私たちはさらに開発したい岩石採掘場の飛行データを持っており、異なるエリアから取り出される岩石の体積を知りたいと思っています。SiteScanの2D空間でポリゴンを描いて体積を測定し、正味体積を求めることができるのは知っていますが、測定したいエリアは3Dメッシュビューでより明確に定義されているため、3Dメッシュタブでそのポリゴンエリアを描きたいのです（2Dビューでは見えにくい木に覆われた崖があり、その崖が測定ポリゴンに含まれると体積が狂ってしまいます）。2D空間でポリゴンを描いた後、3Dで体積を表示・編集して正しい表面を使うことはできますが、ポリゴン自体は編集できないので、2D空間と3D体積編集ウィンドウを何度も行き来してポリゴンを完璧にするのは非常に手間がかかります。もし問題がArcGIS ProとすべてのProfessional Plus拡張機能で簡単に解決できるならアクセス権がありますが、ArcGIS Proで3Dを扱ったことはありません。<\/P>

NicoBonnafoux · Accepted Answer

Hi @McKenzieBredemeyer,

You can't currently measure volumes from the 3D views in Site Scan.

As you stated, the measurement needs to be made from the 2D view using the Volume Measurement tool, then you can visualize the measurement in 3D, and adjust what base surface is being used for the measurement (a level plane at an elevation you define, lowest/highest elevation plane set at the elevation of the lowest or highest vertex you used to define the boundary, a 3D plane defined by the elevation of all the vertices you used to define the boundary, another mission, or a custom surface you upload as a landXML file).

A tip to help you define the boundary of the area you're trying to measure is to display the Digital Surface Model under the Elevation Data tab, and adjust the display range to highlight the base:

Then, once you open the 3D view of the volume measurement, you can adjust the polygon boundary from the right hand map view. If using a 3D Plane as your comparison surface, make sure all your vertices are at the base elevation to get an accurate measurement, this is particularly important if you are measurement a stockpile on uneven base such as an incline.

For your area covered in part by trees, this can be challenging: you may want to use the Digital Terrain Model (DTM) instead of the DSM. The DTM derived from the point cloud and removes non-ground objects such as trees, but is coarser than the DSM.

I don't have an example that perfectly illustrates your scenario, but here you can see the difference between using the DSM versus DTM, and the tree being removed:

I hope this helps!