topic Re: 3D surface calculations methods in 3D Questions

3D surface calculations methods

NausicaaMontanari — Fri, 07 Apr 2023 10:21:28 GMT

With ArcGIS Pro 3.1.1 I tried to calculate 3D surface area of a Polygon that intersect a DTM.

I used two methods:

1) I created a clipped DTM with this tool: https://pro.arcgis.com/en/pro-app/latest/tool-reference/data-management/clip.htm and then I used a 3D tool: https://pro.arcgis.com/en/pro-app/latest/tool-reference/3d-analyst/surface-volume.htm

2) I used this tool: https://pro.arcgis.com/en/pro-app/latest/tool-reference/3d-analyst/add-surface-information.htm

The first result of 3D area was: 192.300,936 mq the second was: 198.125,101 mq

Which is the best method and why there was this difference?

I attach some data and some images.

Thanks Nausica

Re: 3D surface calculations methods

DanPatterson — Fri, 07 Apr 2023 13:01:56 GMT

If the region for which surface area and volumetric calculations are desired is defined by a non-rectangular extent, consider creating a polygon to delineate the boundary of the area of interest, then use the Polygon Volume tool to determine the calculations for the region between the plane defined by the polygon and a given surface.

A raster surface is evaluated using the extent of the center point of each cell, as opposed to the extent of the entire cell area. The resulting analysis will decrease the data area of the raster by half a cell relative to the data area displayed for the raster.

From your first link.

Compare to Polygon Volume if your extent isn't rectangular

Re: 3D surface calculations methods

NausicaaMontanari — Fri, 07 Apr 2023 13:53:28 GMT

Hi,

to use Polygon Volume, I created a Tin from the DTM with tool: Raster To Tin and after I used the Tool Polygon Volume but the result is still different: 188.931,306 mq.

I attach some images.

Thanks

Re: 3D surface calculations methods

DanPatterson — Fri, 07 Apr 2023 15:17:27 GMT

I think you are looking for a "correct" answer, which there probably isn't given the things that affect the results of all the different methods.

Re: 3D surface calculations methods

cpmgisuser — Thu, 10 Aug 2023 09:16:52 GMT

Have been extracting Surface Areas bounded by a Tenement Polygon on a DTM myself using the "Polygon Volume" 3D Analyst tools in ArcGIS Pro v3.1.2.

My first option to do this though was to use a DTM published as a Elevation Layer (hosted) and go to the Analyze - Measure Area tool.

What surprised me was the tool does NOT give you a Surface Area of the DTM but only the flat area of the polygon, sadly!
May as well use a 2D web map instead.

Reason I posted was because you may know if Esri are going to enable this in the Web Scene tools?

Other than that I was just confirming the use of the "Polygon Volume" tool