Sunday, March 14, 2021

Drafting Views have an Origin Too

Drafting views look like a blank sheet of paper we can drop your pen and start sketching in. We can but it might help to know that they do have an origin and you can end up quite from from the origin if we use an external file to sketch over (which happens a lot). I routinely encounter projects that have very large drafting views, when you know where the origin is.

The old trick to find the origin in Revit was to import/link a DWG with a crosshair at the world coordinate system origin. Linked via Origin to Origin places that DWG at the origin of the view. The PyRevit application has a handy function to place a pair of intersecting lines at the origin of a view. I find I just use that now instead. It's about the same number of "clicks" either way.

Now, the natural question to ask is, "Does it matter?" I don't know but if large extents are bad in model views I can reasonably infer that it might also be bad in drafting views. I don't have any evidence that this model was bad because drafting views were huge. I do know that some bad models I've encountered also had drafting views with very large extents. When I deal with a such a model it is one of the things I consider (of the many things, so many things).

Good housekeeping isn't just for the model.

1 comment:

David Kozina said...

After having used AutoCAD for several years, when trying to make the move to learn Revit, this was something that really bothered me - I couldn't see the origin point in a drafting view. So where should I start drawing things?
My solution was to use the 'old trick' you mentioned (which I somehow came up with independently), then added some reference planes to lay out a small detail module. I made a group out of the reference planes and pinned it down. This became my drafting view template, a starting point for all future drafting views. One nice thing about this that didn't take long to discover was that I could copy/paste information from one drafting view to another and it comes in at the same place.
Recently I have had to work on a model with a linked model containing geometry apparently out in the Atlantic somewhere. The model linked in is correctly positioned, but since the elements are positioned so far away from it's internal origin point, whenever I zoom in or pan around the linework just jitters all over the place. Not pretty.