# Thread: Is there really no 3D Surface Area Calculation tool?

1. ## Is there really no 3D Surface Area Calculation tool?

I need to caculate the area of a property based on the topography, is there really no tool inherent to Desktop 10 or 3d Analyst to do this? It hasn't been an issue until we acquired a 10,000 acre tract with an extremely steep ridge and valley topography.

The simplest way I can think of doing this would be to create a grid within my property boundary and calculate individual areas for each polygon. Then caculate slope and create an integer grid of the same size and apply a slope calculation to each polygon's area....there's gotta be an easy way to do this. If it can calculate a 3d perimter and volumes etc, why not a 3d surface area??

Please tell me I'm missing something!

2. ## Re: Is there really no 3D Surface Area Calculation tool?

Originally Posted by tcmartin
I need to caculate the area of a property based on the topography, is there really no tool inherent to Desktop 10 or 3d Analyst to do this? It hasn't been an issue until we acquired a 10,000 acre tract with an extremely steep ridge and valley topography.

The simplest way I can think of doing this would be to create a grid within my property boundary and calculate individual areas for each polygon. Then caculate slope and create an integer grid of the same size and apply a slope calculation to each polygon's area....there's gotta be an easy way to do this. If it can calculate a 3d perimter and volumes etc, why not a 3d surface area??

Please tell me I'm missing something!
Google search of "calculating surface area in 3d arcgis" returned this:

Also found this workflow:
http://www.learnarcgis.com/tutorial_...tutorial_id=44

3. ## Re: Is there really no 3D Surface Area Calculation tool?

Originally Posted by tcmartin
I need to caculate the area of a property based on the topography, is there really no tool inherent to Desktop 10 or 3d Analyst to do this? It hasn't been an issue until we acquired a 10,000 acre tract with an extremely steep ridge and valley topography.

The simplest way I can think of doing this would be to create a grid within my property boundary and calculate individual areas for each polygon. Then caculate slope and create an integer grid of the same size and apply a slope calculation to each polygon's area....there's gotta be an easy way to do this. If it can calculate a 3d perimter and volumes etc, why not a 3d surface area??

Please tell me I'm missing something!
Create TIN then export it to a multipatch feature. In version 10 this will also give you 3D area. (Interpolate Polygon to Multipatch)

Multipatch Surface Area output:
surface_area_field (Optional)
The name of the output field containing the 3D area of the resulting multipatches. This area takes the surface undulations into consideration and is always larger than the planimetric area unless the surface is flat, in which case the two are equal.

In legacy version 9.3.1 or older you could use the TIN Polygon volume tool, just create a polygon feature class equal to the area of the surface you which to calculate. Create a "double" height field in this polygon and set it to the maximum elevation (or greater) of the actual surface. The Polygon VOLUME tool (which in your case will be useless) will also give you 3D_Area and 2D_Area of the surface.

4. ## Re: Is there really no 3D Surface Area Calculation tool?

I'm wondering why such a seemingly simple but very useful tool is not working as it should in ArcGIS 10? The 3D analyst Calculate area and statistic gives an erroneous result. I have tested it with a clipped 1x1km DEM (25 m pixel size), it returns 2D area: 950625 sq m, surface area: 992885.32 sq m, which is less than it should be. This problem was present back since ArcGIS 8, and it is an unpleasant surprise that it was not solved so far (correct me if I'm wrong!).

In the method described by Jakubsisak, in ArcGIS 9.3.1 only the 3D area is calculated, and is still incorrectly less than 1 sq km.

Could anybody please recommend a simple and accurate method of 3D surface calculation?