Build 2 grath in one Profile grapt

[PaulJohns]

Hi everyone, I need to visualize a 3D line above a DEM in a single profile graph. I created a 3D line with an additional height above the DEM (checked in ArcScene — the result looks perfect), and I'm trying to analyze it along its full length using the Interactive Profile tool. I also tried creating a Chart from the Contents pane, but the result is the same — unsuccessful.

ArcGIS generates the profile graph for only one data type at a time: either the DEM (raster) or the 3D line (3D feature). Moreover, the elevation values for the 3D line in the profile are not real — they don’t match the actual Z-values, and I can’t adjust them. The line was created from 3D points using "Feature to 3D by Attribute".

I would be grateful for any advice.

[JinwuMa]

Hi, Paul,

I assume you have two 3D lines. One is the one on the ground, interpolated off the surface, and the other one is above it in the air. You could merge them together into one feature class by using Append GP tool (it doesn't matter which one is merged into which one). After this, in the Contents pane, right-click this merged feature class layer, select Create Chart | Profile Graph (listed at the bottom). Examine the two profile graph lines in the chart window. Their respective height/elevation should be correct. Let me know if there's any problem.

-Jinwu

[PaulJohns]

Hi Jinwu,

Thank you very much for your recommendation. I can now build a "double chart" using your advice, but I still don't understand why the elevation scale is not accurate. I have attached a screenshot — where the red 3D line is 100 meters above the DEM, the green 3D line is at the DEM elevation level only, and the purple points are 3D features labeled with elevation (DEM + 100 m). In the local 3D scene, everything looks correct — but not in the chart. I built both 3D lines (red and green) using 3D points (Points to Line tool). The 3D points were created using "Feature to 3D by Attributes". Could you help me with the elevation scale on the chart?

[JinwuMa]

Hi, Paul,

Thank you for your feedback. Reading your messages, it looks like there's something wrong with the handling of Zs in the data. May I know if it's possible for you to share your test data? You may want to zip it and send it to my email at jma@esri.com. I'd like to take a look at it and find what's causing the problem.

-Jinwu

[PaulJohns · Accepted solution]

Hello everyone. Thanks to @JinwuMa , I finally found a decision. The main idea is to get all data in a planar coordinate system (UTM, Gauss-Kruger, MGRS, etc.). So, the step-by-step algorithm is:

1. Build the project and all your data in a planar coordinate system.
2. Use an operation to extract points from the line (line2point) and extract DEM data to the points.
3. Add the necessary height value to each point using field calculation.
4. Build two lines from the points: one with DEM-only data and one with DEM + height (point to line). Be careful to use 'OrigFID' to ensure the correct line direction.
5. Use the Append GP tool to merge these two lines (see the post above in this topic).
6. Finally, build plots with the two lines (see my attachment).