An excellent (and old) feature of AutoCAD is that you can define your own coordinate system:
The location of 0,0 The direction of the X axis The direction of the Y axis
A custom UCS is a common aid for 3D drawing. For example, if you’re drawing a peaked roof of a house, it’s [...]
Spherical coordinates are a way of specifying coordinates in 3D. Mostly, you use them with the LINE command. They’re good for finding a coordinate that you might use in a solid or surface. (I cover cylindrical coordinates, which are similar, here.)
Spherical coordinates have the format distance<angle<angle. An example would be 6<40<20. The 3 [...]
Some coordinates are easy to find. For example, to find the endpoint of a line, you just use the Endpoint object snap.
But others are more elusive.
For example, recently someone asked me, “I would like to ask if there is a simple way to select a center of a rectangle.”
My answer was: [...]
When you place a hatch inside a closed area, by default, the pattern starts at the origin of the drawing, which is usually 0,0 of the current User Coordinate System (UCS). Since your closed area probably doesn’t start at 0,0, the hatched area starts somewhere in the middle of the pattern.
For simple hatches, [...]