Creating Accelerated Surfaces

This task explains how to create boundary surfaces of a stamped area are created with a constant given distance from a curve selected as spine curve (e. g. the edge of a reference surface).
The goal of this function is to reduce the time needed for perfecting stamped areas like fuel tank caps, door handles, protective bodyside moulding, etc., to improve the quality and to avoid problems due to very large curvature radii.
Open the AcceleratedSurface.CATPart document.

  1. Click the Accelerated Surface icon .
    The Accelerated Surface dialog opens.
 

  1. Select 3D Curve.1 and 3D Curve.2 as Guide and Surface.1 as Support.

  2. Select Type: Distance and enter in the text field Length 20 mm and in the text field Distance 40 mm.

  3. Click Apply to create the accelerated surface.

With this operation, the following steps are carried out:
  1. The selected curves are projected onto the surface and the projected curve is used as guide.
  2. The guide is normal to the surface with the distance specified in the text field Distance (green). The projected curve is edge 1 of the accelerated surface.
  3. From the projected curve is created another curve on the surface with the distance specified in the text field Length (blue). This curve is edge 2 of the accelerated surface.
You can define the following options:
  • Guide: Selects the guide.
    Valid inputs are 3D curves and lines of type Bézier, NURBS, and B-Spline, as well as surface edges.
  • Supports: Selects support elements.
    Valid inputs are surfaces of type Bézier, NURBS, and B-Spline.
 
  • Trim Support: Trims the support surfaces according to the contact edge. The side in which to keep is depicted by the X direction of the manipulator.
    If the guide curve is smaller than the support surface, automatic tangency extrapolation is performed of the trim boundary.
Options tab
 
  • Continuity: Specifies the continuity between created accelerated surface and support from G1 to G3.
  • Divide on Support: In case of support surfaces consisting of multiple cells, the resulting accelerated surface is divided at the cell boundaries in v-direction of the support surface.
 
  • Length: The length is the distance between the guide and the edge of the accelerated surface lying on the support surface (edge 2 in the figure).
    • Individual: Makes it possible to apply individual lengths at each end of the accelerated surface.
  Type:
  • Distance: Defines the accelerated surface by the Distance between the guide and the edge of the accelerated surface lying normal to the support (edge 1).
    • Individual: Allows to apply individual distances at each end of the accelerated surface.
 
  • Radius: Defines the accelerated surface by the curvature Radius at the edge of the accelerated surface lying normal to the support surface (edge 2).
    • Individual: Allows to apply individual radii at each end of the accelerated surface.
 
  • Shape: Modifies the tangent length of the result via the scroll bar or the text box.
    A small value results in a flat and a big value in an embossed accelerated surface.
  See Approximation tab
  See Output tab
  Click 'More Info' to display deviations and output results.
 
  • Display: Depending on the options selected, values are displayed in the graphics area.
  • Deviation:
    • G0, G1, G2, G3: Display of the maximum continuity deviation condition along the accelerated surface edge lying on the support surface.
  • U+V: Display of the UV vectors of curves and surfaces.
  • MFT: Display of the local coordinate system for the moving frame type.
 
     

Manipulators
 
  • Distance: Manipulators for adjusting Length and Distance are only available if Type: Distance is selected. A manipulator for both Length and Distance is available at each end of the accelerated surface.
    When a manipulator is adjusted at one end, the opposite end is modified in unison.
    Only if Individual is selected, you can adjust Length or Distance individually.
    Radius manipulators are not available.
  • Radius: Manipulators for adjusting Length and Radius are only available when the option Type: Radius is active. A manipulator for both Length and Radius is available at each end of the accelerated surface.
    When a manipulator is adjusted on one end, the opposite end is modified in unison.
    Only if Individual is selected, you can adjust Length or Radius individually.
 
  • Invert direction: Displays a moving frame type manipulator on the selected guide curve. Selecting either the 'X' (yellow) or 'Y' (blue) manipulator, selects the required quadrant of the result.
    Note: If a surface edge is selected as a guide, the 'X' manipulator is not allowed to be inverted.

 
  • Shrinking: Shrinks the result along the length of the guide.