Working with AutoCAD Linetypes and Linetype Scales

This is an interesting area that appears to cause us issues when working with CAD files from AutoCAD. I worked with Pat over at Severino on this over the last couple of weeks because it was causing him some issues with speed.

Pat was looking at Drafting Styles and improving the quality of his output using TBC and trying to use TBC more for those purposes. He called me because when he selected e.g. a Layer that had contours on it over a large area that were set to By Layer Linetype and he went into Layer Manager to change the Linetype to eg AutoCADs Hidden 2 Linetype (Dashed) - TBC would take a long time to make the change - as it was regenerating the drawing with the new linetype - for a lot of lines. So what drives that “long time” in this process.

When you draw in the Plan View of TBC, when you use Linetypes, they have a Linetype Scale - typically set to a Linetype Scale of 1 by default.

In addition the Plan View has a Plot Scale set up in Project Settings - View - Plan View and that may be set to 1" = 50’ for example. This has an impact on all Linetypes other than Solid - the patterns of the lines will be rescaled based on this Plot Scale so that at different Plot Scales they still look like a Dashed linestyle etc. Smaller Scales like 1"=50’ will have a tighter dash pattern than large plot scales like 1"=500’ or 1"=5000’ etc.

We did find firstly that we were not managing this as well as we could have been and we have already made some changes that speed things up somewhat. Today we found another issue with Linetype Scaling that we are now also addressing. I hope that this will be improved at the next update.