Orthographic UCSs in a 3D drawing

Each orthographic UCS corresponds to the standard orthographic view of the same name.

you may recall the “glass box” analogy used to visualize the relative orientation of orthographic views in 2D drawings.

The 6 orthographic views of this “glass box” are shown completely unfolded below with each corresponding orthographic UCS.

One way to select an orthographic UCS for the current viewport is to use the Ucs command.

you can right-click in the drawing area at the first prompt to invoke a shortcut and select orthoGraphic.
then pick the desired orthographic UCS from another shortcut.
you can also select these options directly by invoking the desired Ucs option from the Tools + Orthographic UCS menu

The Ucsman command can also be used to select a different orthographic UCS for the current viewport.

select the Orthographic UCSs tab
then select the desired UCS and pick the Set Current button ordouble-click on the desired UCS to make it current.
the depth (see description on the next page) of each orthographic UCS is also reported here.

When you start a New drawing from scratch the depth of each orthographic UCS is zero

which means the initial origin of each orthographic UCS is the same 3D point as the origin of the WCS.

You can use the Move option of the Ucs command to change the depth of an orthographic (or any other) UCS.

when you invoke this Ucs option you are prompted to select any other 3D point for the new origin of the current UCS.
you can also use the Zdepth sub-option and specify a distance to move the origin in the Z axis direction of the current UCS.

For example, the Right orthographic UCS is shown superimposed on the WCS with both a zero (initial value) and non-zero depth.

The UCS II toolbar has a drop down list in which you can select an orthographic UCS or the World UCS ( the WCS).

UCSORTHO

Your current UCS may change without your having to explicitly use the Ucs or Ucsman commands.

you can configure your system to switch to the appropriate orthographic UCS when you restore an orthographic view.

UCSFOLLOW

You can also configure your system to change views automatically so that the current view is Plan (Top) when you change your UCS.

PRACTICE USING ORTHOGRAPHIC UCSs

»1) Close the drawing from the previous exercise if it is open.

»2) Open the T303_2.dwg drawing in your personal folder.

»3) Make sure that OSNAP, OTRACK & POLAR buttons are On in the status bar.

»4) Pick Tools + Orthographic UCS + Right.

»5) Pick Tools + Move UCS & use an Endpoint (Intersection) osnap near P1 as the new origin for the Right UCS.

6) Pick Draw + Rectangle. Type TT at the keyboard to invoke the Temporary Tracking point tool. Hold your crosshairs over the Endpoint (Intersection) osnap marker (do NOT left- click) to acquire this as an alignment point for tracking.

7) Move your crosshairs along the bottom edge of this wall to invoke a 0 degree tooltip angle. Type 30 at the keyboard for the distance and press <enter>.

8) Move your crosshairs up to invoke a 90 degree tooltip angle. Type 35 as the distance and press <enter> to supply this point as the first corner of the rectangle. Then enter @72,48 for the other corner of the rectangle.

The location of the origin point in the new UCS is not important when you use tracking to supply points in 3D (as in the last few steps)

provided the UCS is parallel to the desired drawing plane and the X and Y axes are oriented in the desired directions.
you could have moved the UCS to any corner on this wall
you could have even kept the Right UCS at the WCS origin and used the same method to sketch this window.