Gemini IFC issue

JSN

Is it far away from the origin?

Jim.persson

@JSN Yes ít is.

JSN

Yes ít is.

Why? Is there a specific reason for it? Big coordinate values can create lots of issues (not only in Solibri) as computers are not so intelligent as they pretend to be … anyhow usability is in all kind of software much better when you keep it close to the origin.

Matti

Any possibility to get this model or part of it?

Jim.persson

@matti-kannala Yes it is it´s a small IFC. i´ll send it to you. can i have your mail since i´d rather not post it here

Jim.persson

@jsn Yes ther is it is a gorund works modell for produktion so they are modeled in the swedish SWEREF system

JSN

@Jim-persson I do not know about SWEREF system but general recommendation is to locate the IFC Site entity at the Project Origin and you should be working close to the Project Origin. If there is still a need to define model coordinates relative to a national datum you should use the dedicated objects like a Survey Point. This way, a far offset is stored in the IFC file not as part of the element coordinates, but rather generally. So you shouldn’t put the geo referencing coordinates to the transformations. Instead you should provide latitude and longitude to the site and the have the coordinates in relation to them. This is actually the workflow sufficient for UTM-, Gauß-Krüger-, BMN- or Swiss Coordinate System as far as I know.

A site may include a definition of the single geographic reference point for this site (global position using WGS84 with Longitude, Latitude and Elevation). The precision is provided up to millionth of a second and it provides an absolute placement in relation to the real world as used in exchange with geospational information systems. If asserted, the Longitude, Latitude and Elevation establish the point in WGS84 where the point 0.,0.,0. of the LocalPlacement of IfcSite is situated.

http://docs.buildingsmartalliance.org/MVD_WSIE/schema/ifcproductextension/lexical/ifcsite.htm

Anyhow, would be very informative to learn more about the different workflows regarding georeferencing as it seems like there if still a lot of confusion.

Matti

Hello,
I investigated this:

The model has big translations on object and geometry level. If translation is needed it should be done e.g. on Site object.
The objects are moved +6km in x-axis.
The geometries are moved -6km in x-axis and +6km in y-axis.
The x-axis movements are zeroed (6 - 6 = 0)
We could fix this in Solibri and there are some similar open cases. I add this to Solibri bug database.
Workaround is to move big translations to object level from geometry

Jim.persson

@matti-kannala Thanks I see the Issue I´ll investigate some more on our end as well why the software exports like this.

Still interesting that the graphics works well in other softwares

Jim.persson

@jsn That is our usal workflow as well. but in this instance the software uses WCS as an origin.
This is t0 the best of my knowlege how this software handles things as im not working directly with the software