ArchSite Compass

[paullee]

Slightly off-topic, not directly about Compass but about 'Real World Coordinate' with External Reference.

As of FreeCAD_0.18-16110-Linux-Conda_Py3Qt5_glibc2.12-x86_64.AppImage:-

- *.fcstd are not shown in file open dialog
- *.FCStd are shown
- only BuildingPart is supported
- Better Building (/ Site) or the whole file to be loaded ....?

And as Site has Longitude, Latitude, Declination or OriginOffset, & Elevation, Compass... etc...

Could External Reference (with an option) to automatically use these information as its Placement?

[EDIT]

Could it also be simple External Reference so any acceptable object can be 'Referenced' within same file - bit like Block in AutoCAD then ?

Screenshot from 2019-04-30 03-19-26.png (215.12 KiB) Viewed 1051 times

[yorik]

Indeed there should be some way to "re-position", or switch, in a way or another, between model position and real-world position.
The arch reference might be a very good way to do that, indeed: Reference a site object, and be able to relocate it as in real-world.

There are still some problems, though, the arch site is a quite hybrid object, which has its own shape (unlike Buildings/BuildingParts), so using it in a reference doesn't work quite like buildingparts... And there is the annoying thing that if you reposition a site, the contained buildings should be repositioned as well... It's still not very clear to me how to do that elegantly.

[yorik]

@furti, is there any reason why the compass properties are in the Base part of the site object? They would seem more appropriate to me in the View part, no? Mind if I change?

[furti]

I had it in the view object at the beginning. But then the Update declination property was added and since this is also in the site object i moved the compass there.

But sure. Feel free to move the compass to the view object if it fits better there

[yorik]

Done in git commit ff1fb11af
Since the compass feature is only a few days old, I didn't add any mechanism to migrate older versions of sites...

[furti]

Perfect

Since the compass feature is only a few days old, I didn't add any mechanism to migrate older versions of sites...

I also don't think this is needed at all. Ther is nothing important that can get lost in case someone used the feature already.

[hlg]

This looks pretty cool. I found two minor issues in the 0.19.17433 dev release, not sure whether these are fixed already after that.
1. I have a project in mm where the compass still seems very small (the site and terrain extend over almost 100m, the building over 50m).
2. When I turn the site invisible, the compass disappears as expected. But when I turn it visible again, the compass remains invisible.

[hlg]

I have added some lines to populate declination and compass rotation on IFC import and to export the value to IFC as well: https://github.com/FreeCAD/FreeCAD/pull/2360 This is is based on the IFC2x3 way of specifying true north, which is still available in IFC4. It will probably become obsoled with the work of Dion Moult in PR #2259, where also the new way of georeferencing is supported.

I was wondering whether declination and compass rotation are really the same or rather opposite angles. To my understanding, site declination would be the difference between site CS y-axis and true north, whereas the compass roation would be the difference between true north and the project (WCS) y-axis - hence the inverse value. At the point of IFC import we always have zero site rotation (I think we loose the IFC rotation due to coordinate resolution in IFCOpenShell), which makes things a bit easier. Can someone clarify the intended direction of the declination value?