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Using three-dimensional coordinates

Specifying coordinates in three-dimensional space is similar to working in two

dimensions, except that you also use the z-axis to locate coordinates. Three-dimensional

coordinates are represented in the format x,y,z (for example, 2,3,6).

Using the right-hand rule

To visualize how CAD.direct 2021 works with three-dimensional space, use a

technique known as the right-hand rule. Hold up your right hand in a loose fist with

your palm facing you. Extend your thumb in the direction of the positive x-axis and

your index finger upward in the direction of the positive y-axis. Then extend your

middle finger straight toward you in the direction of the z-axis. These three fingers

are now pointing in the positive x, y, and z directions, respectively.

You can also use the right-hand rule to determine the positive rotation direction. Point

your thumb in the positive direction of the axis about which you want to rotate, and

then curl the rest of your fingers toward your palm. These fingers are curling in the

positive rotation direction.

Entering x,y,z-coordinates

When working in three dimensions, you can specify x,y,z-coordinates as absolute distances

in relation to the origin (the 0,0,0 coordinate point at which the three axes intersect) or as relative coordinates based on the last point selected. For example, to specify a point 3 units along the positive x-axis, 4 units along the positive y-axis, and 2 units along the positive z-axis, specify the coordinate 3,4,2.

Entering spherical coordinates

When working in three-dimensional space, you can use spherical coordinates to specify

a three-dimensional point by entering its distance from either the origin (absolute distance) or the last point (relative distance), along with its angle in the xy plane and its angle up from the xy plane. In spherical format, you separate each angle with the open angle bracket (<).

Thus, to draw a line from the origin to a point 10.2500 drawing units away, at an angle of 45 degrees from the x-axis and 35 degrees from the xy plane, start the Line command, and then respond to the prompts as follows:

Start of line: 0,0,0

Angle • Length • <Endpoint>: 10.2500<45<35

Entering cylindrical coordinates

When working in three-dimensional space, you can also use cylindrical coordinates to specify a three-dimensional point. You specify a point by entering its distance from either the origin (absolute distance) or the last point (relative distance), its angle in the xy plane, and its z-coordinate value.

In cylindrical format, you separate the distance and angle with the open angle bracket (<) and separate the angle and z value with a comma. For example, to draw a line from the last point to a point 7.4750 units away, at an angle of 27 degrees from the xaxis in the xy plane and 3 units up in the z direction, start the Line command, and then respond to the prompts as follows:

Start of line: (select point A)

Angle • Length • <Endpoint>: @7.4750<27,3