# Thread: Identifying 3D Cartesian Coordinates

1. ## Identifying 3D Cartesian Coordinates

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Hello,
So I've been creating 3D structures for a little while, but when I create an object, the identification system asks me for (say I'm making a line) the x&y of the initial point, then the length and the angle to make the second point. It always assigns the z coordinate at 0. How do I change it so that I can identify the start and endpoints using x,y,z terminology?

The 3D polyline allows me to do this for the first point, but not the second. And I'm not sure how to do this for other shapes.

2. Welcome to CADTutor.

There are quite a few options avaiable for setting up your Dynamic Input preferences.
Hopefully these screenshots willl help you to set it up how you like it.

3. I just found one more system variable setting that will likely make you happy.

4. When entering coordinates, AutoCAD assumes a 0 Z value unless you specify one. If you like to draw by entering coordinates, just add the Z value to your string but there are easier ways to draw in 3D for most.

5. Attach a copy of the drawing to your next post so we can see for ourselves what you are doing.

6. Originally Posted by lorims
Hello,
.... How do I change it so that I can identify the start and endpoints using x,y,z terminology?
Simply enter
10,12,24
at the command line or DynInput prompt.

You should learn about x,y,z filters as they are very helpful in 3D as well as 2D.
Start a line command,
enter .xy
pick a point
now it will ask for Z
enter a value, continue from there.

You can also use .z first and then continue, etc.

7. Thanks all! When I'm specifying a third point for the 2nd endpoint of a rectangle (say first point is 0,0,0, and I want second point to be at 1,1,1) It says "2D point or option keyword required." Is there a way to get around this?

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Originally Posted by lorims
Thanks all! When I'm specifying a third point for the 2nd endpoint of a rectangle (say first point is 0,0,0, and I want second point to be at 1,1,1) It says "2D point or option keyword required." Is there a way to get around this?
Nope, not directly, a lot of autocad geometry is linked to the current ucs, so you can enter a start point anywhere in 3D space but any further points have to be parallel to the ucs, this goes for polylines (rectangles), circles etc, the "line" command is free from this restriction as are 3d polylines. The only way you can get around this is to change your ucs to match the new drawing plane or first draw the object and then use the align command.

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