Using Dynamic Cutting Planes

This task shows how to analyze a surface using parallel cutting planes. The intersection of the planes with the surface is represented by curves on the surface. From these curves, you can visualize the porcupine analysis. This analysis is dynamic, meaning that you can interactively modify a number of parameters to fine-tune the analysis.

Open the CuttingPlane1.CATPart document.

  1. Select the surfaces to be analyzed.

  2. Click the Cutting Planes icon
    A reference plane is displayed along with the default number of cutting planes, and the corresponding projected lines onto the selected surface.
    The Cutting Plane dialog box appears.

    You can define analysis parameters from this dialog box, that is:

    • The plane in which the analysis is to be performed, using the three icons (Parallel Planes, Planes perpendicular to curves, Independent planes)
    • The boundaries of the set of planes (available in Parallel Planes mode only):
      • Automatic: the analysis is performed based on all selected surfaces bounding boxes. The cutting planes are evenly distributed within this area, one being necessarily located on the reference plane if the Step option is active.
      • Manual: the analyzed area is defined by the Start and End values.
    • Number/Step: choose whether you have a set number of planes or a distance (step) between two planes. In the latter case, the number of planes depends on the size of the analyzed area. This option is only available in Parallel Planes and Planes perpendicular to curves mode.
    • Start/End: in manual mode, defines the distance at which the first (start) and last (end) cutting planes are located on the reference plane axis.
    • Options facilitating the analysis reading:
      • Activates/hides the representation of the cutting planes
      • Activates the display of the curvature comb (Curvature option)
    If you click the Settings button, the Curvature Analysis dialog box appears.
    The 2D Diagram command of the curvature analysis is only available with the Freestyle Optimizer license.
    The result is similar to using the Porcupine curvature analysis, except that it displays spikes for each intersection curve. See Performing a Curvature Analysis.

  3. Click the Parallel planes icon:
    The compass moves to the reference plane center, and from then you can manipulate the reference plane.
    If you want to perform an analysis in planes perpendicular to curves, select a curve and click the Planes perpendicular to curves icon:
    Using the Planes perpendicular to curves type, you can check the On curve option in the Number/Step area to create perpendicular planes:
    • Select a reference curve.
    • Check the On curve option.
    You can create several planes: right-click the reference plane and select Keep this plane from the contextual menu.
    Planes are added to the specification tree.
    This option is only available with the Planes perpendicular to curves type.
    If you want to perform an analysis in independent planes, click the Independent planes icon:
    You can use the contextual menu on the Independent planes icon to create the a plane.
    Each created plane is added to the current list of planes used for the analysis. See Stacking Commands for further information.

  4. Activate the Manual mode, set the Step value to 30, and the Start value to -150 and End value to 150.
    The planes are automatically relocated.

  5. Click OK in the Cutting Plane dialog box, when you have finished the analysis.
    The analysis (identified as Cutting Plane Analysis.x) is added to the specification tree.
    • Click OK to interrupt the function while keeping the analysis on the surface, so that it is dynamically updated when deforming the surface.
    • Click Cancel to interrupt the function and remove the analysis.
    • Right-click the intersection curves to actually create the curve on the analyzed surface. You can choose to create only the curve over which the pointer is (Keep this intersection curve option) or to "drop" all curves onto the element (Keep all intersection curves option).
    The Keep this point option is also available from the contextual menu.