altered WCS

[Ells]

We get drawings in from some architects and Surveyors that have the WCS at an odd angle. How do you get the WCS to appear vertical and horizontal rather than at an odd angle? I realize that the whole drawing will rotate with the WCS set to Vertical and Horizontal.

[Patrick Hughes]

Type UCS > "W" then "plan"

 

You will then be in the World Coordinate System

[Ells]

Thanks for the tip. For me I had to type "plan" first and then "W". Next question is how did the WCS get rotated to begin with?

[Patrick Hughes]

Well there are all sorts of ways,

 

The first that comes to mind other than user interaction is a misbehaved lisp routine that perhaps alters the UCS during execution without properly returning to the original UCS, or if the routine is escaped out of (or crashes) the error handler is missing or improperly resets it.

 

One guess that I have also is some people dislike having the UCS icon on and turn it off. This can result in some problems when users are no longer aware of the coordinate system they're in. A rotated UCS will be readily apparent but if the UCS is still "aligned" with the WCS but the origin is offset funky things can take place.

 

I advise to always keep the UCS icon on, and typically always showing in the lower left corner.

[Ells]

Thanks for the information. I have used the UCS alteration quite often but the WCS I do not change. My only guess is that in a surveyors drawing they must set the draiwng up so it fits good on paper but still have the "Y" of the WCS pointing North. Your information is very informative and something to keep in mind when translating or in the event of a crash. Thank you

[AlinOz]

In actual fact, surveyors work the opposite to the rest of the world. We typically use 0 degrees to the East and Measure angles in an anticlockwise direction. Surveyors and Civil guys have their 0 to the North and measure the angles clockwise. So, if you get a Surveyor's/ Civil drawing you may need to go into the UNITS and adjust them accordingly or else everything you draw will not be as it would seem.

 

As for the use of the UCS, there are some excellent reasons for changing it. Lets say you're working on a Building that is boomerang shaped... You can rotate the UCS around the Z axis to match the odd-angled 'wing' of the building. If you then use the PLAN command to rotate the view to match the current UCS (simply PLAN, Enter, Enter), the drawing view will rotate to allow you to work more comfortably with everything being horizontal and Vertical... Even Ortho works here nicely too.

 

If you're into 3D, you will find the UCS your greatest friend as you can move it around to suit the face that you're trying to work on...

 

Get to know and love the UCS - it's very handy indeed