Adding survey points to Recap pro, result is not showing set height

[Anonymous]

Hello everyone,

I'm having the following issue:

With my current project, i have to add survey points in my pointcloud.

To do this i've followed our usual workflow:

• Registrate/build the project in Scene
• remove unwanted points
• Load the Scene project into Recap to create the pointcloud

After it's done processing/indexing i always update the origin.
The next step is to register the survey points.

After registering all the survey points, the pointcloud doesn't appear to be in the correct height.

The 3 images attached to this post should clear that up, the RecapSurveyPoint is the original point placed by me, in which i have copy pasted the coordinates provided to me with the Autocad file (see AutocadHeight).

Should the Z value be the same or should it be an average of all the survey points on this side of the building?

I've also put the pointcloud in Revit and tried to measure the Z height there (and if this was correct), however i couldn't find an way to do this.

Is this also possible?

Thanks in advance!

Niels

[anil_mistry]

Hi @Anonymous,

Thank you for participating in our Community! Z value in Survey points you are providing is just reference point for you to align with other scans. Your height of the building should be Z coordinate when you click on that point. Looks like you are comparing two different thing. Do you know the actual height of location that you are trying to find? Did you compare your x,y,z in ACAD?

Thank you and have a great day! 

[Anonymous]

Hi @anil_mistry,

I don't know the height of the building only of the area surrounding it. I can reference these by using the data provided in Autocad.
This is the important part (the height of the ground). So i thought adding several survey points to the ground (which are in the same spot as the surveyor measured), and setting the Autocad XYZ values in the XYZ values of the sureypoint would set the ground to the correct height.

So to set the ground to the correct height i have to measure the height of the building, add this to the surveyed points and put this into the Z value?

[berson.guillaume]

Hi @Anonymous, how many survey points did you add to your project ? Two won't be enough to change de coordinates in Recap. I also see that your RMS is 192839235mm, should be around 20 or 30mm to be good...

You talked about Revit. Coordinates system are not convenient in Revit. You should be able to control that everything is good in Recap and/or in Scene.

I just don't understand why you don't use your survey points in Scene ? You should do all the registrations / coordinates thing in Scene and then import it in Recap so it would already be in the good coordinates. 

[Anonymous]

Hey @berson.guillaume,

Our points have been measured on the ground with no reference for Scene to auto detect those.

I've tried manually adding the points, but Scene doesn't recognize my points with the survey points.

A Faro Scene representative told me that the survey points are identified trough geometry in Scene, and we use reference spheres for the links between the scans (which haven't been measured).

So the Scene problem is i can't tell scene what (self added) point is a survey point. That's why i went to Recap and added 4 survey points to get the correct height. However Recap refuses to set the correct height.

[berson.guillaume]

Scene also let you pick any point. At least that's what I used to do with SCENE 5. I'm not using SCENE anymore but I'm pretty sure you can do it.

Anyway, it seems you're facing a problem I also had, which is large numbers. Try to truncate your coordinates to have shorter numbers to see if it works. It worked for me (you can't change coordinates once Survey Point is created so you'll have to delete them and add new ones).

[Anonymous]

So i've also tried to truncate the coordinates, that didn't fix the problem. However everytime i update the gps (and return to project) the origin is situated at a different location. Could me updating the origin at the start have something to do with it?

For example,  does the origin have to be at the exact center of the "world"? Or can i update the origin to my prefered spot and let the height be calculated from there (without the origin moving from that spot)?

[berson.guillaume · Accepted solution]

Could me updating the origin at the start have something to do with it?

You don't have to "Update Origin" in order to get your project to the Survey Points location. I would suggest you to "Reset Origin".

[anil_mistry]

Hi @Anonymous,

I'm just checking in to see if you need more help with this. Did the suggestion that @berson.guillaume provided work for you?

If so, please click Accept as Solution on the posts that helped you so others in the community can find them easily.

[Anonymous]

Hi @anil_mistry,

I've tried it, it has not worked yet. But i'm processing a new clean recap (without all my experimenting). And i'll try the solution provided by @berson.guillaume

[anil_mistry]

Hi @Anonymous,

Thank you for your reply. Please, let me know if suggestions that @berson.guillaume provided work for you or need additional assistance. 

Thank you and have a great day!

[danny27585]

Hello there,

Why not try to go back to the building do 4 scans with 4 - 6 black and white targets have a surveyor shoot them and then just use Recap survey points...seems the easier option to me.