UCS Definition (Optional)

 

Land F/X requires that either the WCS (World Coordinate System) or a UCS (User Coordinate System) be active to control the viewing of a site. DO NOT use DVIEW, as this is similar to a camera view, and callouts, etc., cannot orient to this control, they only orient to the currently active WCS or UCS.

 

AutoCAD basically allows three methods to orient the view of a site.

§	The WCS (World Coordinate System) is what most surveys and Civil Engineered drawings are based upon. This is where the origin point (0,0) is usually some survey point that the site layout is based upon, and North is straight up, along the Y axis.

§	A UCS (User Coordinate System) allows the user to orient the view of the site to their fit their needs for the drawing, while still allowing for some form of coordinate system.

§	A DVIEW twist, which turns the viewing of the site to fit the needs of the drawing, but with a camera view.

 

An analogy of these would be: you are walking down a street that is facing due north…this is viewing the world based on the WCS, with north straight ahead. You wish to view the house to your right, so you can:

§	Grab the entire world and rotate it so that the house is in front of you, thus physically changing the WCS to suit your needs…this is difficult and can upset the space/time continuum.

§	Turn your body and face the house. This is establishing a new User Coordinate System, UCS, while still respecting the existing WCS of the world.

§	While looking north down the street, you could point a camera at the house and view the house through the view finder…this is an artificial way to view the house, and is akin to the DVIEW in AutoCAD.

 

The logical method is 2, establishing a new UCS. In AutoCAD, you should really never change the WCS relationship that came with the drawing, neither physically rotating the site, or changing the 0,0 origin point. Using DVIEW does not work because it is artificial, and Land F/X functions will not work, such as callouts or even just placing plants, because Land F/X is still oriented to the current coordinate system.

 

Define a New UCS

 

 

 

Select New UCS to define a new UCS orientation. The AutoCAD Command Line will ask:

 

Specify new origin point, <0,0,0>

 

Select a point for your new origin. This is not particularly critical as to where it is. If your new viewing angle is to match a curb or building angle, you may want to snap to the end of a line of one of these objects for the origin point. You may also Right Click to leave the origin at 0,0, the same as the WCS origin.

 

You will define the X Axis direction. The X Axis will define the horizontal viewing axis of the new view you are creating, so make sure it is accurately in the correct direction. The Command Line will ask:

 

Setting snap angle—select entity, enter angle <0>, or click to specify:

 

Either:

§	Select an entity, such as another line, that you want the orientation related to.

§	Enter a number for an angle.

§	Click two points to define the orientation (perhaps the most common way).

 

After selecting two points the Command Line will ask:

 

Select Work Area, <None>:

 

If you have one or more Work Areas defined, select the desired one with the pick box. If no Work Areas are defined, you will be prompted to enter a name for the UCS:

 

UCS Name dialog.

 

Enter a name for this UCS. The UCS will be created, and the viewing of the site will relate to this new UCS.

 

Restore a UCS

 

 

 

Many projects will have several UCS views established. To restore a previously selected one, click on Restore UCS. The Command Line will ask:

 

Select Work Area, <WCS>:

 

Either pick on a Work Area or right click for the WCS (World). It is evident that if you are using several UCS views, you should also use Work Areas to define where those views are active.

 

If you have no Work Areas defined, you will get a dialog box listing any UCS’s you have defined.

 

UCS Restore dialog box listing the UCS’s you have defined in the drawing..

 

Select the desired UCS view and select OK.