Hello All,
Again I have searched the forum about the topic I have a query about, but I could only find a couple of threads over 6 years old, and even then not exactly about my question.
I was wondering if it is possible to set a relationship between the grid systems (Grid manager) and the Geographical Coordinates? Let me explain in more detail.
Right now it looks as if the grids are all referenced to the design center of the files. So when I set up a grid system it will appear on the same position - relative to the design center "0,0,0" - in all the models in a workset. In a way this makes a lot of sense. As a user we can reference all models to eachother with their origins set to "coincident" and everything works well.
However once we start using the GCS - and make sure it is set to the same coordinate system in all files correctly - there is a new option when referencing models "Geographic" which is very interesting when combining models/drawings with a "local" grid/coordinate system on the one hand together with the "Geographical" grid/coordinate system on the other hand.
Now to the actual question/issue:
I also don't see a workaround for the latter case. I can of course not activate the grid system in this file/model/drawing so it's not on the wrong location. But I don't see a way to reference the grid system in another way because it's stored in a DGNLIB, not just a plain drawing file.
Is my explanation making sense? :) If not, I'll be happy to try and make it clearer!
Hi Johan,
Grid Systems are dynamically displayed (calculated) in the active file controlled by the options selected in the Grid Systems Manager:
These calculations need to take place close to the centre of the design file (i.e. within the SWA); grid system calculation does not perform well at large distances from the design file centre and has been associated with application crashes in some circumstances.
The two ways to use Grid Systems in relation to the real world are:
Geo-referencing is our recommended option.
Regarding the second option:
Prior to update 8 Grid Systems could be exported to a set of models within the active file. However we found a bug in U8 that has broken this function.
Update 9 will include an improved export grids function that exports the grids to a new DGN file:
The workaround for U8 is to manually export grids to a separate DGN.
Marc
Hello Marc, thanks for the answer!
The workaround you suggest, the button "Export Grids To Design" is what you mean is broken in U8?
How does this manual export work then?
Sorry, I omitted the screenshot of the existing tool, "Export Grids To Design" will be added in U9.
Hi marc,
i think I have asked this question a while back also, but in the case of georeferenceing transforms,
Correct me if this has been updated since, but I don't think it is possible to associate a grid with a relative or transformed GCS. ie. i have a project consisting of 4 blocks, 2 are orthogonal to the design file, and 2 are rotated.
Master files are all located with GCS transform close to 0,0, To ensure robust modelling, we create transforms for each block that are orthogonal to design plane. however, the grid still displays in the same location, relative to 0,0 and the other blocks.
I would see it that we should be able to associate a grid with a GCS, or transform or at least have a heirarchy of Site grid v's building grid with origin/placement points, so that when working with multiple blocks and buildings we are able to apply, building grids and site/,
Ideally for a large project, when attaching a building(reference) to a master file, an attachment option should be available relative to project Grid system. so that ie, I can attach building A with Grid A to plot origin or master grid marker A
Hello Duncan,
I think what you are describing is also what I wanted to do at first. However I do understand the reasoning not to link the grids to the GCS because that might result in grids being very far from the design file center.
What you and I would like to do by transforming the grids (mainly the rotation would be important to me) should be done in OBD by using the "Rotate ACS". If I'm not mistaken an ACS is automatically created for each floor and reference plane defined in the "Floor Manager". By using the correct transform on the buildings in the Floor Manager the ACSes will thus be translated and rotated accordingly. This solves most of the issue in my opinion.
Only downside to rotation in the floor manager is that it's only possible to do it by manually entering values. Not in the graphical interface, which makes it not very accurate in case of special angles. When it's just 20deg or 45deg it's no problem of course, but when the rotation must be 12,4687592458deg you actually need to increase the angle accuracy of the interface. And even then it's not 100% accurate because rounding is always present. But this issue is known to Bentley and I think they are working on improvements.
Hello Johan,
I think we are talking about the same principles from ever so slightly different angles. in the Floor Manager we have Floors(levels), Buildings, and Site.
I would effectively like to be able to define a local (or file origin) origin to a grid (say a building that repeats multiple times, modelled at 0,0), and enable placement markers, or plot origin points within the site level of the Floor Manager so I can place multiple references of the same building relative to plot origins through a site.