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: Offset and enter in the text field Length 20 mm and in the text field Offset 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 offset normal to the surface with the distance specified in the text field Offset (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: Selection of the Guide.
    Valid inputs are 3D curves and lines of type Bézier, NURBS, and B-Spline, as well as surface edges.
  • Supports: Selection of support elements.
    Valid inputs are surfaces of type Bézier, NURBS, and B-Spline.
 
  • Trim Support: The support surfaces are trimmed 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, then automatic tangency extrapolation is performed of the trim boundary.
  Options tab
 
  • Continuity: Surface continuity can be set. Options available G1, G2, and G3
 
  • Length: Specification of the distance between guide and edge 2 of the surface to be created.
    • Individual: You can apply an individual length value via manipulators at each end of the accelerated surface.
      In the example shown, the individual lengths are -50mm and -30mm
 
  • Type:
    • Offset: Specification of the distance between guide and edge 1 in the text field Offset.
    • Radius: Specification of the curvature radius at edge 2 of the surface to be created in the text field Radius.
 
  • Offset: Specification of the offset value for the option Type: Offset.
    • Individual: You can apply an individual Offset value via manipulators at each end of the accelerated surface.
      In the example shown, the individual lengths are 32mm and 14mm.
 
  • Radius: Specification of the radius value for the option Type: Radius.
    • Individual: You can apply an individual radius value via manipulators at each end of the accelerated surface.
      In the example shown, the individual Radii are 120mm and 30mm.
 
  • Shape: The shape slider allows the user to modify the tangent length of the result with a form of tension.
     
    Note: This option is only available if Type: Offset is chosen.
  See Approximation tab
  See Output tab
  Click onto the 'More Info' button 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.
  • UV: Display of the UV vectors of curves and surfaces.
  • MFT: Display of the local coordinate system for the moving frame type.
 
     

Manipulators
 
  • Offset: Manipulators for adjusting Length and Offset are only available when the option Type: Offset is active. A manipulator for both Length and Offset 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 when Individual is selected, you can adjust Length or Offset 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 when Individual is selected, you can adjust Length or Radius individually.
 
  • Invert direction: Upon the selected guide curve a moving frame type manipulator is displayed. By selecting either the 'X' (yellow) or 'Y' (blue) manipulator, the user can select which quadrant of the result is required.
    Note: In case of a surface edge being selected as a guide, the 'X' manipulator is not allowed to invert.

 
  • Shrinking: Upon creation of the accelerated surface, the result can be shrinked along the length of the guide.