Civil 3D Support Question of the Day

Civil 3D Question of the Day:


I have my linework and points in a drawing that gets XREFED into ALTAs and other design files.

When I want to freeze a particular layer to hide the points all of them freeze!  I can't leverage styles easily because you can't manipulate styles via XREF.

What is the best way to set up my point styles?


ANSWER:


There are two ways (ok maybe 1.5 ways) to accomplish what you are after.

The first place Civil 3D looks for Styles and layers is the Description Key Set.   The overall point layer always comes from the Description Key set.  In the event you have a field code that doesn't match, the layer ends up as the default set in the command settings.



Method 1: Forget Layers, Use Point Groups


This is what I train my newbies to do, since I have the benefit of being able to brainwash them in the ways of Autodesk.

Advantages:

• Takes Layers out of the picture


• Quick control of many points at once.


• How the software was intended to operate (or so I assume)

Disadvantages:

• You still need to worry about layers when it comes to plotting - so you will also have a description key set.  (Otherwise, because you are not using layers you would lose the ability to use VP Freeze)


• Can't manipulate Styles via XREF.

1. Set up a bunch of point groups in your template that you anticipate using.  Or make them in the current project.  Doesn't matter.

Leave the _All Points group as-is.  There will be no overrides on the styles here, just in case you want to see how they were interpreted by the Description key set.

					All the new groups that you create will utilize the style and label style overrides. Create an _All Points (Style Override) to display all points uniformly.
			Don't forget to make a No Display group that includes All points.
		Then, when it comes time to turning certain points off, use the Point Group properties.  Right-click the very top of the list as shown.
				Shuffle around the point hierarchy as needed. The order in which the points groups  appear here is which group controls the style.  Because points can belong to more than one group at once, you need to determine the precedence.  For instance, a Topo point will be in the All Points groups, Topo group and No Display.  If No Display is higher in this list, that's the style that "wins". Points that reside in groups ABOVE No Display will show up.  Points that are in groups BELOW No Display will be hidden.

Method 2: Layers only Method


Since the first stop for Points is the Description Key Set, use this to set the layers. And use Traditional CAD Freezing to control what groups are visible/not visible.

Advantages:

• Many people are used to this method


• No worries about VP Freeze

Disadvantages:

• Need to Simplify styles


• Can be cumbersome to remember what points went on what layer.


• Points that do not match description keys are all sent to the same layer.

Below is the Wisconsin DOT Description key listing.  They have quite a few description keys, each with its own layer.



Regardless of what is in the style layer-wise the layer from here is the layer most people use when freezing & thawing.

The way I think of it is, assuming you are familiar with how blocks operate: You have the layer that the block is inserted on.  Some blocks may also have layers hidden inside of them (not if I taught them CAD, but you get the picture). The insertion layer of a block is analogous to the point's layer from the description key set.  Those "hidden" block layers are similar to the layers within a style.  99.9% of the time if you want to freeze a block, it is the insertion layer that you are aiming for.  Same for points.

In other words, the layers you see inside of a point style are more or less irrelevant.  The only time they will rear their heads is if you explode a point down to its core components.  UNLIKE a block, changing the LAYFRZ settings to Entity will not give you access to these underlying layers.

My Wish for the Future:

A lot of headache could be avoided if point groups had data shortcuts. That way I could make a point group that contained the points I wanted to show in my new drawing and make a reference to them.  Perhaps there is some logic or programming reason that this can't be done.  But I would love it!  This would also facilitate surfaces using a point group that did not exist in the same drawing.

-Lou

DVIEW > Twist VS Rotate UCS

Clients teach me new things nearly every day.  This week the lesson I learned is the difference between using DVIEW to rotate your design on screen and rotating the UCS about the Z axis. All of my CAD career, I've used DVIEW. For a long time, when someone mentioned rotating the UCS in a 2-D drawing I would cover my ears and go "Llalalalalalalala." Before this week, all I knew is that rotating the UCS caused major problems in survey software.

The company I trained this week had always used the UCS to angle designs into a more comfortable drafting mode.  After telling them that they should use DVIEW instead, they naturally asked, "Why?" At a loss for a real reason, I've taken it upon myself to dig deep and understand what the difference is.

A little background…

UCS stands for User Coordinate System.  When you first enter a drawing your UCS lines up with the WCS.  WCS stands for World coordinate system where Y is up, X is right and Z pops out of the screen at you.  WCS is a nice, normal place, where things don't go wrong. In any new drawing, the world coordinate system lines up with the user coordinate system, much like a rectangular piece of paper whose edges line up with the edges of the desk it is sitting on. Rotate the piece of paper and you are rotating the Coordinate system.  If instead you just started working on the drawing by scooting your chair to another position, that is more like what DVIEW > Twist does.

DVIEW > TWIST & SNAPANG

DVIEW is accessed by typing DVIEW at the command line. (Shocking, I know.) DVIEW stands for dynamic view, and represents the position of your eye (or in Autocad terms, the Camera) in relation to the canvas.  After you start the DVIEW command, you are prompted to select objects or select a DVIEWBLOCK.  I usually go for DVIEWBLOCK unless I'm just going to eyeball the rotation with a line or two as reference for the rotation. Type TW for twist and key-in your rotation angle.  A positive angle will rotate the camera counter-clockwise.



You can leave the drawing as is, but your cursor will have rotated too.  I usually use SNAPANG to untwist the cursor back to parallel with the bottom of the screen.

Rotate Coordinate System

To rotate a coordinate system, use the view tab and find the Z axis rotation. Enter the angle you wish to rotate the view.



Rotating the UCS is redefining where the zero angle is, therefore a positive angle will rotate the coordinate system clockwise.



PLAN <CURRENT>


Like DVIEW, the rotated UCS leaves you with a wonky cursor. Key-in PLAN, then hit enter for Current to straighten things up.



Un-twisting


To un-twist from DVIEW, I type in PLAN, then W for world. (If you know of a slicker way, drop me a comment).  To untwist a UCS, click the world button on the View tab.

Now that I understand the differences, I totally understand rotating the UCS if lots of text is going to get placed relative to the rotation.  However, that is the only compelling reason to do it.  Overall, I still recommend DVIEW over rotating the UCS.  A drawing can only have one UCS at a time, but you can use DVIEW in every viewport if you wanted to.  A rotated UCS can seriously impact how XREFS line up and how blocks are inserted.  A rotated UCS will cause XREFs and blocks to come in at unexpected locations - you are changing the coordinate system after all!

DVIEW (Pros)	UCS (Pros)
Different dview twists can be set in different   viewports	Text placement follows UCS
Works better when XREFS and blocks are inserted	Can use cad objects directly to set angle (DVIEW   requires you to measure first)
Can be used in multiple viewports
Preferred method for many 3rd party apps

So next time one of your co-workers insists on rotating the UCS, you don't need to cover your ears and spout nonsense words.  Get the whole story - then decide!

-HUGS, Lou

PS: Sign up NOW for my AU class Civil 3D for Beginners. November 29, 2011 1:00PM. Only a few spaces left! (Also, I bring candy.)