AutoCad Command Line for 3D Rotate

Select entity;

Type Y, enter;

Specify point on Y axis:<0,0,0>: enter

Also you'll have to specify the second point on the Y axis. Sorry.

You could always put your rotational lines (as many as you want with different colours if you need) onto another layer and select it from there..Hope this helps..

Command: _ucs
Current ucs name: *WORLD*
Specify origin of UCS or [Face/NAmed/OBject/Previous/View/World/X/Y/Z/ZAxis]
<World>: _3
Specify new origin point <0,0,0>:

Try working with your UCS. I use tools>>>new ucs>>>3 point (commandLineAbove) to pick points on my geometry so that I am rotating around the Z axis most of the time. The first point you pick is Z, next is your X axis, and the last point picked serves as your Y axis.

If you want to rotate around Y. Rotate your UCS around the X axis by 90 degrees so that Z is now your Y axis and then rotate your geometry with the RO commmand and select the object to rotate. (commandLineBelow)

Command: _ucs
Current ucs name: *WORLD*
Specify origin of UCS or [Face/NAmed/OBject/Previous/View/World/X/Y/Z/ZAxis]
<World>: x
Specify rotation angle about X axis <90>: 90
Command: ro
ROTATE
Current positive angle in UCS: ANGDIR=counterclockwise ANGBASE=0
Select objects:

Enjoy!