Need to extract X, Y, Z of Point Clouds in schedules - But how?

[alexliz]

I am using the IES-05 Object Inventory schedule as a starting point. I am reporting on Objects only, which are located in the Point Cloud layer in my project.

Fields reported in my schedule are Library Part Name (so I see which Point Cloud it is), together with the three 'Survey Coordinate' fields. I thought I was getting the real coordinates of where the point clouds in my project are, but it turns out that I am not.

Anyone could please advise what the 3 fields are returning?

The project Survey point is set at Easting/Northing/Elevation all set to 0.0000.

EDIT: I am now thinking that this has to do with the fact that I have set the project location, using the Latitude and Longitude fields - am I right? At any rate, what is the way to get a table with the values for X/Y/Z values for a number of objects in my project (or other elements as well)?

Thanks.

[alexliz]

Good morning Ricardo,

Thanks for your replies. I am struggling with understanding the usefulness of the Survey Point coordinates, their logic even. Here's what I am doing:

I place the Survey Point at Project Zero, so that North is up (i.e. North is at 90°, on the positive Y axis).

I create a few elements in my plan: a couple of hotspots; a simple chair, and a point cloud; all at specific positions - easy, round X and Y values from that Project Zero/Survey point. Their X and Y coordinates are now reflected in the Coordinate 17 labels which I have added for each of those elements, except for the ones of the point cloud.

By the way, if North is set to anything other than 90°, then X,Y do not show correctly; Archicad returns the trigonometric calculations of these, based on North rotation. In my view there should be another way to extract the correct X,Y for any element in some schedule. To achieve this currently, I have to make North upwards (i.e. at 90°), then export my X,Y values, then remember to point North where it should be in reality.

EDIT - SADLY, UPON FURTHER INVESTIGATION, WHAT I MENTION BELOW IS NOT THE SOLUTION. But I do feel I'm getting closer. I'll come back with a later post when I get time. Please read the remaining of this 'with a pinch of salt'.

But I have now solved the issue - it's Graphisoft's bad; I would say a case of really bad programming and/or user interface. I explain:

The point cloud is entered by clicking in plan view, and its 'handle' is somewhere within the point cloud. This point (i.e. the location of the handle hotspot) is likely determined by the Lidar scanner output file, by how the data is imported into Archicad, and how Archicad builds the corresponding LCF and GDL files.

Once placed, the hotspot still gets displayed in plan view (when the point cloud is selected). It's the point that shows as selected when you select the point cloud. It also shows in the Object Selection Settings, in the 'Preview and Positioning' section, the only spot you can see. You can select the point cloud by clicking on any of the many (hundreds, thousands etc) points making it up, but you will only ever see that hotspot as a selected point in any view.

It turns out that Archicad ignores that special spot when calculating the position of the placed point cloud. What it does is, it calculates the bottom left corner of the imaginary bounding box around the point cloud and shows the coordinates for that point instead (!!!). <--- THIS IS THE POINT THAT I HAVE NOW DISCOVERED TO BE SLIGHTLY INACCURATE. THE LOCATION RETURNED BY THE SURVEY COORDINATE X,Y FIELDS IS VERY NEAR BUT NOT EXACTLY THAT CORNER POINT.

You can confirm this by selecting the point cloud, then issuing a Move or Rotate etc command. Upon clicking the first click after that (to move or to rotate it etc) you see the virtual bounding box appearing.

If anyone from Graphisoft is reading this and cares enough please fix.

See also screen grabs.

 

 

[Erik Bjornhage]

@alexliz 

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Thanks for your replies. I am struggling with understanding the usefulness of the Survey Point coordinates, their logic even. Here's what I am doing:

It turns out that Archicad ignores that special spot when calculating the position of the placed point cloud. What it does is, it calculates the bottom left corner of the imaginary bounding box around the point cloud and shows the coordinates for that point instead (!!!).

I'm not exactly sure what you are trying to achieve but from my perspective, the Survey Point is an extremely useful tool - when dealing with information exchange in real world coordinates (RWC). When it comes to you point cloud it really depends if it is GeoReferenced or not. If it is then, when placed at 0,0,0, it should be located very far from you Project Origin.

If you need to exchange your model in RWC then you cannot model in that location, so you model near project origin but export using your Survey Point as origin.

If you need coordinates for objects placed in your model, whether they are RWC or Local - then, as @Ricardo Lopez said, use the Coordinate Dimensions-object. If you place you objects correctly it should display the right coordinates in your schedule.

You can set one object with coordinates relative to your Survey Point and another object with Local Cordinates. We do this all the time when it comes to delivering set-out plans for slabs and such - works perfectly.

Your Project North also changes your Survey Point Coordinates as you are, in effect, rotating your entire coordinate grid.

If I have misunderstood your problem, then please explain what I have missed.
Good luck.