Point entities in CFD-GEOM are placed in an XYZ (Cartesian) coordinate system. This is also normally known as the world space coordinate system or the absolute frame of reference for your geometry. The Construction Plane tool enables you to position a construction plane in space and place points on that construction plane to generate curve entities. The construction plane, when visible, is drawn as a uniform mesh to provide visual feedback on its location and orientation.

Construction Plane Options

To display the construction plane in the work area, click  the Construction plane button on the Entity Toolbar.

Figure 1.  Construction Plane icon on the Toolbar 

To reorient the construction plain, select the Construction Plane Option from the “Miscellaneous Tools”  on the Geometry tab.

  Figure 2.  Miscellaneous tools button with Construction Plane option outlined.

CFD-GEOM has several options for setting the construction plane. Choose the Construction Plane you desire, based on the following descriptions:

• XY, YZ, and XZ - You can specify the coordinates or depth of a construction plane perpendicular to any of the coordinate axes without having to specify three points which uniquely determine the plane.
• Three Points - You can specify three points that uniquely determine the plane.
• Point and Normal - You can select a point, then specify a normal to set the construction plane.
• Normal to Curve - The Normal to Curve option enables you to place the construction plane normal to any location along a specified curve. Choosing this option opens a slider that adjusts the location of the construction plane along the specified curve. This can be a useful tool if you want to generate curves which are normal to a curve at a given location.

Set the Parameters based on the following descriptions:

• Snap to Grid - This toggle button allows precise placement of points on the construction plane. While this feature is active, the intersected point is automatically snapped to the nearest coordinate value as specified via the plane step size.
• Depth - Controls the depth of the construction plane perpendicular to any of the coordinate axes.
• Step Size - Controls the gradations of the mesh and provides visual feedback on the physical values on the plane.
• Increments - Controls the overall size of the construction plane graphic.

To generate curves using a construction plane: 

There are multiple instances when a construction plane is useful.  One such example would be while creating curves on a complicated surface as seen in Figure 4. Here a curve is created where the construction plane intersects the surface.

To create this curve, do the following:

1. Turn on the construction plane by checking the Construction Plane button as shown in Figure 1
2. From the “Miscellaneous Tools”, select the XZ axis and input the desired depth.
3. From the “Intersection Tools,” select the “Intersect Surface/Plane” option.
4. Select the surface and then select the “Construction Plane” option from the menu.
5. Apply