Cad underlay - extend issue

[Karol_Piroska]

Has anyone else got problem with extend tools not recognising lines from linked CAD? Other tools like align or even detail line does snap to all linework, but the extend tool has somehow issues with many lines.

Screencast:

https://autode.sk/2siwgmz

Thank you

[mariah.ferranti]

Hello @Karol_Piroska,

Thank you for participating in the forums! I was able to reproduce this behavior in Revit 2019, and earlier versions.

It looks like DWG elements that are rectangles, or multi-segment P-lines, all have issues with the trim/extend tool in Revit. I'm currently working with the team to see if this is an expected limitation, or a known issue, and will keep you updated with what we're able to find out! 

[mariah.ferranti]

Hello @Karol_Piroska,

Thank you for your patients while I check in about this! I was able to talk to the team and it looks like multi-line segments (Plines with more than one segment, rectangles, things like that) are a current limitation of the tool. 

To get around this, if the link file is not active and just a reference, you can use EXPLODE in AutoCAD to explode these to individual segments.. but I would not recommend this for any file that is being continually worked on. 

The team did let me know this is something they may be able to consider if logged as a Revit Idea. 

[mariah.ferranti]

Hello @Karol_Piroska,

I wanted to see if you had questions or concerns about the information provided. If helpful, feel free to select accept solution so this post comes up higher in the list of search results for other users, or reply back if you need more help! 

[Karol_Piroska]

@mariah.ferranti thank you for your reply.

I did few trials and mostly it is as you mentioned. The trim/extend does work only for lines or archs.
Ubfortunately, for whatever reason, exploding existing polyline does not work. If I explode it and copy the very same line aside, the tool works for the copied element, but not for the original. It doesn not work always as you can see in the screecast below:

https://autode.sk/2AQy5fg

In fairness this should not be considered as a "new idea" but rather a bug in the software.

[mariah.ferranti · Accepted solution]

Hello  @Karol_Piroska ,

Thank you for your patients while I work with our Development team on this issue. I was able to collaborate with them and come up with a workaround, along with some extra info on why this works the way it does:

• Though this functionality exists for tools like the align tool, the trim/extend tool had not been expanded to parse out these lines that Revit reads as multi-segment lines from the DWG. The team may investigate adding this in a future release, but would like to see it added as an idea in order to see what kind of demand exists for this function. 
• The workaround: When originally working with the team, they suggested exploding the DWG. I had expected this was an explode in AutoCAD, but they actually  meant import/explode in Revit. This does work. If you don't want to import the AutoCAD file directly into your working Revit file, you can do the following:
  • Create a new Revit file
  • Import the DWG to this
  • Explode the imported DWG
  • Save this file as a Revit file
  • Link this new Revit file with exploded DWG into the existing Revit file. This one will be recognized when using the trim/extend tool, and won't bring all of the DWG elements into your file like importing/exploding directly would. 

Please let me know if you have any further questions, concerns or feedback! 

[Karol_Piroska]

thank you @mariah.ferranti 

that workaround could do. Certainly it is not ideal as new drawing revisions cannot be simply reloaded, but at least we know about this issue.

Just to summarize, any lines that are connected at end points Revit reads as multisegmented lines (no matter if it is lines or polylines) and the trim/extend tool does not currently work for these.