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      <div class="title_topic5" id="xps10_pagetitle">Flow and cross curve examples</div>
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               <p class="para_td"><a class="links" href="javascript:void(0)" onclick="top.openFile('mfgmilling/streamline_overview.html');return(false);">Overview </a></p>
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               <p class="para_td"><a class="links" href="javascript:void(0)" onclick="top.openFile('mfgmilling/streamline_list_ht.html');return(false);">How To </a></p>
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               <p class="para_td"><a class="links" href="javascript:void(0)" onclick="top.openFile('mfgmilling/streamline_drive_method_dialog.html');return(false);">Options </a></p>
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               <p class="para_td"><a class="links" href="javascript:void(0)" onclick="top.openFile('mfgmilling/streamline_list_rt.html');return(false);">Related Topics </a></p>
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      </table><br><div class="title_division">Examples of acceptable flow and cross curve combinations</div>
      <p class="para_division">In the examples below, flow curves are red, cross curves are blue. Grey curves show the cut pattern.</p>
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                  <p class="para_td"><img align="bottom" src="graphics/streamline_flow-cross_ok-1.gif" border="0"></p>
                  <p class="para_td">Typical 4&ndash;sided configuration.</p>
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                  <p class="para_td"><img align="bottom" src="graphics/streamline_flow-cross_ok-6.gif" border="0"></p>
                  <p class="para_td">Intermediate cross curve selected to give more shape control for the drive surface.</p>
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                  <p class="para_td"><img align="bottom" src="graphics/streamline_flow-cross_ok-7.gif" border="0"></p>
                  <p class="para_td">Intermediate flow curve selected to give more pattern control for the drive surface.</p>
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                  <p class="para_td"><img align="bottom" src="graphics/streamline_flow-cross_ok-10.gif" border="0"></p>
                  <p class="para_td">Four&ndash;sided drive surface with one intermediate flow (for better pattern control) and one intermediate cross (for better shape control) added. You can add as many intermediate curves as needed.</p>
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                  <p class="para_td"><img align="bottom" src="graphics/streamline_flow-cross_ok-4.gif" border="0"></p>
                  <p class="para_td">Three&ndash;sided with two flows and one cross.</p>
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                  <p align="center"><img align="bottom" src="graphics/streamline_flow-cross_ok-2.gif"></p>
                  <p class="para_td">Three&ndash;sided with two flows and two cross curve sets. The second flow curve set contains a single point.</p>
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                  <p class="para_td"><img align="bottom" src="graphics/streamline_flow-cross_ok-12.gif" border="0"></p>
                  <p class="para_td">Two sided drive surface.</p>
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                  <p class="para_td"><img align="bottom" src="graphics/streamline_flow-cross_ok-8.gif" border="0"></p>
                  <p class="para_td">Two sided drive surface with a cross curve added to better define the shape.</p>
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                  <p class="para_td"><img align="bottom" src="graphics/streamline_flow-cross_ok-3.gif" border="0"></p>
                  <p class="para_td">Two closed loops selected. A cross curve gives shape to the drive surface and defines the start points.</p>
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                  <p class="para_td"><img align="bottom" src="graphics/streamline_flow-cross_ok-9.gif" border="0"></p>
                  <p class="para_td">Two closed loops selected. (The point at top is technically the second closed loop.) Two cross curves give more control over the shape of the drive surface.</p>
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                        <td valign="top" align="left"><img align="left" src="../graphics/tip.gif" alt="Tip" title="Tip"></td>
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                           <div class="para_tip">
                              <p class="para_tip_body"><b class="uiTerm">Automatic</b> selection only identifies the two exterior loops of the cut area. With <b class="uiTerm">Specify</b> you can manually select any number of closed loops to create flow curve sets.
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                  <p class="para_td"><img align="bottom" src="graphics/streamline_flow-cross_ok-5.gif" border="0"> 
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                  <p class="para_td">Two closed loops configuration with one flow curve and two closed cross curves.</p>
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      </table><br><div class="title_division">Examples of implied cross curves (added to connect the flow curve ends)</div>
      <p class="para_division">When you do not specify cross curves, the software creates linear segments to connect the flow curve ends.</p>
      <p class="para_division">In the examples below, flow curves are red. Implied cross curves added by the software are blue dashed lines.</p>
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                  <p class="para_td"><img align="bottom" src="graphics/streamline_flow-cross_ok-11.gif" border="0"></p>
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                  <p class="para_td"><img align="bottom" src="graphics/streamline_flow-cross_ok-13.gif" border="0"></p>
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                  <p class="para_td"><img align="bottom" src="graphics/streamline_flow-cross_ok-14.gif" border="0"></p>
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                  <p class="para_td"><img align="bottom" src="graphics/streamline_flow-cross_ok-15.gif" border="0"></p>
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                  <p class="para_td"><img align="bottom" src="graphics/streamline_flow-cross_ok-16.gif" border="0"></p>
                  <p class="para_td">Flow curves do not intersect in this example. The result is a twisted surface.</p>
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                  <p class="para_td"><img align="bottom" src="graphics/white_space.gif" border="0"></p>
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      </table><br><div class="title_division">Examples of unacceptable flow and cross curve combinations</div>
      <p class="para_division">In the examples below, flow curves are red, cross curves are blue.</p>
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                  <p class="para_td"><img align="bottom" src="graphics/streamline_flow-cross_ng-1.gif" border="0"></p>
                  <p class="para_td">Two points only define a line segment, which is not an acceptable drive surface.</p>
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                  <p class="para_td"><img align="bottom" src="graphics/streamline_flow-cross_ng-2.gif" border="0"></p>
                  <p class="para_td">One curve set is closed and one curve set is open. This is not allowed.</p>
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                  <p class="para_td"><img align="bottom" src="graphics/streamline_flow-cross_ng-3.gif" border="0"></p>
                  <p class="para_td"> The flow curves are not properly aligned.</p>
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                  <p class="para_td"><img align="bottom" src="graphics/streamline_flow-cross_ng-4.gif" border="0"></p>
                  <p class="para_td"> The flow curves are not properly aligned.</p>
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                  <p class="para_td"><img align="bottom" src="graphics/streamline_flow-cross_ng-5.gif" border="0"></p>
                  <p class="para_td">A single flow curve is not enough information to create the drive surface.</p>
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                  <p class="para_td"><img align="bottom" src="graphics/streamline_flow-cross_ng-6.gif" border="0"></p>
                  <p class="para_td">One curve set is closed and one curve set is open. This is not allowed.</p>
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                  <p class="para_td"><img align="bottom" src="graphics/streamline_flow-cross_ng-7.gif" border="0"></p>
                  <p class="para_td">The flow curve directions don't match.</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">Flow curve directions must match. Cross curve directions do not have to match.</p>
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      </table><br><div class="title_division">Additional considerations</div>
      <p class="para_division">When you select flow and cross curves:</p>
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         <li>
            <p class="para_item">Flow and cross combinations with two or more closed loops (for example, a truncated cone) have some limitations.</p>
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               <li>
                  <p class="para_item">You can&rsquo;t move the start point. This is sometimes important to prevent twisting of the drive surface/drive curves. You may have to manually create a cross curve that passes through the desired start location, or move the start segment to the desired location. The software preserves the start point of flow 1 and aligns the start points of the remaining flow curves. In most cases this produces good results and no manual corrections are required.</p>
                  <p class="para_item">In the example below, the default start point (1) would create a twist in the drive surface. Manually adding a cross curve (A) at the desired location (2) produces a better drive surface.</p>
                  <p class="para_item"><img align="bottom" src="graphics/guided_manual_c_curve.gif" border="0"></p>
               </li>
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         </li>
         <li>
            <p class="para_item">If the flow curves are complex, add intermediate cross curves, as shown below, to produce a better drive surface.</p>
            <p class="para_item"><img align="bottom" src="graphics/guided_simplify.gif" border="0"></p>
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