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      <title>Choosing a Coordinate System</title>
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      <div class="title_topic3" id="xps10_pagetitle">Choosing a Coordinate System</div>
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      <p class="para_topic"> Choose WCS or Absolute to specify which coordinate system the system references when locating points. The WCS (work coordinate system) is the default. You can place the WCS at any location and in any orientation. The absolute coordinate system is a fixed coordinate system.</p>
      <div class="title_division"> Offset</div>
      <p class="para_division"> This option allows you to construct a point in relation to a reference point. The location can be based on the absolute or the work coordinate system.</p>
      <p class="para_division"> When you select an offset, it remains in effect until you select another offset method or exit the Point Constructor. The last point created is the base point (reference location) from which the next point will be offset. The default setting is None, (no offset).</p>
      <div class="title_division">Multiple Offsets</div>
      <p class="para_division"> The Point Constructor allows you to offset a point from the last point specified. This is useful if you want to specify many points where each point is offset from the previous point.</p>
      <p class="para_division"> For example, suppose you want to specify a quick row of points. You might specify the first point, set the offset to rectangular, and offset the remaining points from each previous point. By choosing OK a number of times you quickly generate a row of points.</p>
      <p align="center"><img align="bottom" src="graphics/com_subfunfi18.gif"></p>
      <p class="para_division"> Using Offset to Specify a Row of Points</p>
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            <td valign="top" align="left"><img align="left" src="../graphics/note.gif" alt="Note" title="Note"></td>
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                  <p class="para_note_body">To exit the Point Constructor when using an offset, first return the offset setting to NONE and click OK. If you do not select the NONE setting, the Point Constructor continues to offset points from the last specified point.  </p>
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      <p class="para_division"> Use the following options for locating a point at an offset:</p>
      <div class="title_division"> Rectangular Offset</div>
      <p class="para_division"> This option allows you to offset a point by entering values that represent the X, Y, and Z directions (for absolute; XC, YC, ZC for the WCS) from a reference point.</p>
      <p class="para_division"> The coordinate system you select and the orientation of that coordinate system determine the direction of the offset.</p>
      <p class="para_division"> The origin of the coordinate system has no effect on the offset.</p>
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         <p align="center"><img align="bottom" src="graphics/com_subfunfi15.gif"></p>
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      <div class="title_figure"> Rectangular Offset</div>
      <div class="title_division"> Cylindrical Offset</div>
      <p class="para_division"> This option allows you to construct an offset point by entering cylindrical coordinates.</p>
      <p class="para_division"> You define the coordinates by specifying a radius, an angle, and a distance along the Z axis (Delta -ZC). The radius and the angle always lie in the XC-YC plane.</p>
      <p class="para_division"> A cylindrical offset can reference the absolute coordinate system or the working coordinate system.</p>
      <p align="center"><img align="bottom" src="graphics/com_subfunfi14.gif"></p>
      <p class="para_division"> Cylindrical Offset</p>
      <div class="title_division"> Spherical Offset</div>
      <p class="para_division"> This option allows you to construct an offset point using spherical coordinates, two angles and a radius.</p>
      <p class="para_division"> Angle 1 always lies in the X-Y plane, and Angle 2 defines the elevation of the offset point from the X-Y plane. The radius defines the distance between the base point and the offset point. A spherical offset can reference the work coordinate system or the absolute coordinate system.</p>
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         <p align="center"><img align="bottom" src="graphics/com_subfunfi13.gif"></p>
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      <div class="title_figure"> Spherical Offset</div>
      <div class="title_division"> Vector Offset</div>
      <p class="para_division"> This option allows you to offset a point by specifying a direction and entering a distance in that direction. The direction is defined by selecting a line. The point is offset toward the end of the line that is closest to where you selected the line.</p>
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         <p align="center"><img align="bottom" src="graphics/com_subfunfi12.gif"></p>
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      <div class="title_figure"> Vector Offset</div>
      <div class="title_division"> Offset Along Curve</div>
      <p class="para_division"> This option allows you to define an offset point along a curve by a specified arc length distance or a percentage of the total curve path length. Note that lines can also be used as the &quot;curves&quot; for this offset.</p>
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         <p align="center"><img align="bottom" src="graphics/com_subfunfi11.gif"></p>
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      <div class="title_figure"> Offset Along a Curve</div>
      <p class="para_division"> How you select the curve determines the direction in which the offset will occur. Select the curve away from the reference point on the side of the curve you want to locate the point.</p>
      <p align="center"><img align="bottom" src="graphics/com_subfunfi10.gif"></p>
      <p class="para_division"> Determining Offset Direction</p>
      <div class="title_division"> Reset</div>
      <p class="para_division"> Use Reset to quickly set the X-Y-Z coordinate fields to 0.0, and to set the Offset option to None.  </p>
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