You will generally get better results by using Insert instead of Import when bringing DGN/DWG/DXF files into Rhino.
There are a few reasons for this, mostly because the Rhino template has good default document settings, layer options, and annotation styles. If you Import using “no template,” it can be more work to get the model scale looking good in Rhino.
Here’s a typical approach for importing a DGN — you’ll need to work with it and see what’s best for your files.
- Begin a new file in the units you want. For example, mm small.
- Drag and drop the DGN/DWG/DXF file and use the Insert option. ← this is very important.
- Insert it as an embedded block, using the origin as the insertion point. Once it’s in,
Explodeit to break it down into individual geometry. - You’ll likely see that the DGN has a huge title block that doesn’t help us. We need to isolate the geometry in the lower left corner and get the text scaled to be readable. If you need the title block, preserve it and turn it into a block for later use.
- After inserting, zoom in and delete the title block geometry. The TB does not belong in the model. It needs to be added to the Layout.
- Confirm that the floor plan geometry is full size in your selected units. If the door opening is 3’, test to make sure the scaling correct. If not, scale the geometry before you continue.
- In Options → Annotation Styles, turn off Layout Space Scaling. For the styles in this model, you should be able to leave Model Space Scaling checked. (See the Help docs for a description of what each of these settings does.) This matters because Rhino handles text scaling differently than MicroStation, AutoCAD, and other CAD programs. If this setting isn’t configured correctly, the symptom is huge text after inserting the file into Rhino. This is a document setting, so it can stay on in native Rhino files and be turned off just for your imported files.
- Once the floor plan curves are visible, use SelText to select the text.
- Then use the command ScaleTextHeight to scale it.
- Scale it up by 2 a few times, and once the text starts getting readable, use a smaller factor like 1.1 to dial it in.
- Now you’re ready to create a layout and set the detail scale to 1:200, or whatever you need.
- Purging can also help clean up the file of unused named objects.
Sincerely,
Mary Ann Fugier