creating editable 2d linework from a 3d geometry

Dear All,

I'm working with Microstation V8i, and hitting a roadblock when trying to create editable 2d linework from a 3d geometry. 

I know how to create 2d drawing and sheet models from a 3d geometry. The issue is that these are / appear to be merely visualisations of the model, but not editable drawings in themselves. With that I mean drawings that can be manipulated independent from the original 3d geometry.

All tutorials I have found imply that changes are done in the 3d model, which are then referenced into established plan or section callouts. While this may be useful in many instances, I want to pull an accurate 2d section or plan from a 3d geometry, and then work on the linework itself, offsetting existing lines, trimming, etc…

My workaround so far has been to use a ‘clipping plane’, export 'visible edges' and then import the generated .hln file into a 2d drawing. This is quite cumbersome, while at the same time I would prefer to actually us the existing plan and section callouts. I’m hoping for a way to transfer the callouts into an editable set of lines. I hope I’m making myself clear…

Maybe someone is so kind and can point me in the right direction?

Thanks, Urs

  • I know how to create 2d drawing and sheet models from a 3d geometry. The issue is that these are / appear to be merely visualisations of the model, but not editable drawings

    Usually a 3D model is referenced to a 2D sheet.  References are, by definition, read-only (non-editable).  If the 3D model is changed, the new geometry is shown automatically in the 2D sheet.

    I want to pull an accurate 2d section or plan from a 3d geometry, and then work on the linework

    It's an unusual request.  I'll leave others to comment on the wisdom of that approach.

     
    Regards, Jon Summers
    LA Solutions

  • Any linework that can be "manipulated independent from the original 3D geometry" will no longer be updated by 3D geometry changes. They will be "dead" data. Is that really what you want?

    If you really, really want just a set of lines that has no connection to your 3D model, I know that previous versions of MicroStation have the ability to Export...2D, where you choose the view window that shows which direction of the drawing you want to export. I don't use it much at all, so I can't speak to how well it would serve your purpose. I imagine CONNECT has the same file export ability.

    I recommend against that, however. Design changes happen at every point in the process, and once you exported your 2D lines, they would no longer reflect any changes in the design. Your plan sheets could become outdated very quickly, and every time you wanted to "update" them, you would have to do all the cleanup over again. If you DON'T update them with every change, your plans will end up just being wrong.

    I would strongly suggest familiarizing yourself with the 3D viewing tools, clip boundaries, saved views and the other tools that are available in MicroStation to allow you to use your 3D models as references to create sheets.

    MaryB

    Power GeoPak 08.11.09.918
    Power InRoads 08.11.09.918
    OpenRoads Designer 2021 R2

        

  • As a rule in MicroStation, if you have a 3d model and you use the 2d call out tools to generate the 2d views, the 2d views will be lined to the 3d model.  Thus if the 3d model changes the 2d views automatically update.  This is how it has been designed to work.

    I agree, this does limit you in terms of editing line weights colours etc.  In the CONNECT version, there is an option to HIDE Cached elements, but this is unset, if someone switches the drawing view from Dynamic/Cache switch, so you could loose all your hard work.  We generally advise to not use this option.

    However, to overcome your issue .............

    What I have done in the past is to create the 2d view in a different DGN file, there is an option for this in the call out 'create drawing' dialog.

    If you open this 2d DGN drawing, I then copy the reference file so it appears twice. Make sure it is in the same location

    Then on the 2nd copy I merge into master.  

    The reason I do this is. . . . .   . . . . . the element become editable.

    I then edit the line work and turn OFF the reference file.  If the 3d model changes you will be warned of this effect on your Cached file, so to see what the changes are, I simply turn the reference file ON and compare the active data to the reference data

    Ian 

  • Thanks for everyone’s feedback. I agree that in most cases you want your 2d views linked to the 3d model. In this particular situation however I need them detached.

    Ian – Your answer sounds very promising, exactly what I was looking for. But when I “merge into master”, the plan callout disintegrates… (see attached screenshot).

    I thought the model might have issues. But it behaves fine when otherwise manipulated, and if I export a clipped view of the model as ‘visible edges’, the plan comes out clean.

    Can you think of another way to translate the callouts into independent linework?

    best, U

  • I don't use callouts but I assume they are similar to manually placing a clip volume (which I have done many times).

    I would simply activate the Clip Volume (if necessary I would also have an ACS per Clip Volume if the CV was not orthogonally aligned so the relevant ACS would be enabled too), set the view to front plane of the ACS so that its perpendicular to the CV, disable the forward cutting plane (within View Attributes dialog) leaving only the 'Cut' plane active and then use Visible Edges to create the required linework.