# Numbers on Potree

I am new to potree and GIS in general. I am using potree by way of WebODM and I am able to generate a pretty 3D map of the images I took from a drone. But I am having a hard time making sense of the measurements that I get out of the various tools in potree.

Here are a few examples with screenshots.

Let's say I want to measure the volume of top part this decorative bush.

I highlight the parts I want to measure like so:

And I get these numbers.

But what do they mean? What unit is the volume measured in? What are those x,y,z and alpha, beta and Y values and rx,ry and rz?

Next up, the Height profile tool.

Let's say I want a height profile of the entire width of the map. I would select it like so

And then when I open up the 2d profile tab, I would get this:

Again, I am not sure of what those numbers mean. I am guessing the x,y,z are the coordinates from the 3d map and the colour is the RGB value of the point in the point cloud. But what about the rest of those values, and how do I get the height of a point from this?

Questions:

• What unit is the volume measured in?
• How do I measure the height from the height profile?
• Is there an online instructions manual for potree that I can look this stuff up? There seems to be quite a bit more to potree and I would really like to get familiar with it.
• – Fran Raga Aug 5 '19 at 8:08
• Thanks for your reply. Does that mean the volume is in cubic meters? What about the height profile tool? – DrkStr Aug 5 '19 at 10:35

If you're using Potree in your browser, you can open your browser's developer tools and interact with the viewer. If you go to the console, you can enter the following line to get the unit of your x,y,z system (while viewing the Potree Viewer webpage):

viewer.lengthUnit

It will return the string of the unit, such as "m" for meters. If you are using Potree within your site and the above method does not work, you might want to search for your implementation of the PotreeViewer class to use the .lengthUnit method on.

## Edit (height profile):

The height is the Z-value in the height profile. If you hover over the line, you can see the value of your coordinates (x,y,z). Try moving your mouse on a spot where the height changes rapidly, and you'll see your Z coordinate changing correspondingly.

Clicking on 'CSV' or 'LAS' at the top right corner of the height profile allows you to download these numbers if necessary for other purposes or integration in code / other software.

• Thanks for the reply :) Any idea why the unit of measure is not printed alongside the volume reading? Also, what about the height profile, how would I measure the height from the height profile. – DrkStr Aug 10 '19 at 6:18
• Printing the unit of measure everywhere takes up space. I guess the developers decided that this was unnecessary, as the unit is probably based on the input data. Describing which type of data is shown to the user probably happens before any visuals or data are shown, so the user should already know this. There's only so much info you can show before an interface becomes cluttered, and being cluttered would beat the purpose of this viewer. I edited my answer for more info about the height profile. – JiyuuSensei Aug 12 '19 at 8:15
• Wow, thanks a lot man. :) – DrkStr Aug 12 '19 at 12:22