Transform Affinity

The Transform feature is a type of feature modifier. This capability modifies a set of functional features of the active body by applying a transformation to them individually. The affected features retain their full functional behavior.

  • The command allows you to define four types of transformations:
    • Translation - Translates one or more features.
    • Rotation - Rotates one or more features about an axis.
    • Scaling - Resizes one or more features based on a ratio factor.
    • Symmetry - Applies a Symmetry transformation by reflection.
    • Affinity - Transforms the absolute size by multiplying a scale ratio.
    • Axis to Axis - Transposes the geometry from one reference axis system to another.

    An Affinity transformation changes the absolute size of the selected functional features by multiplying a scale ratio in a given direction to a geometric coordinate value. Unlike the Scale transformation, each direction of the referenced axis system may use a different scale factor. If the scaling ratios for the three directions are dissimilar, you may result in a deformed features.

    The following inputs are required:

    Axis system: By specifying an origin, the XY plane, and the direction of the X axis, the system will create a reference axis system that the scaling ratios will be applied to.

    • Origin: The new reference axis origin.
    • XY plane: The XY plane of the new reference axis system.
    • X axis: The X axis of the new reference axis system.

    Ratios: Specifies the scaling factor in a particular axis direction. The user may specify a scaling factor for the X, Y, and Z axes. Default is “1.0” for each direction.

  • X Ratio: the scale to apply to the x axis.
  • Y Ratio: the scale to apply to the y axis
  • Z Ratio: the scale to apply to the z axis.

This scenario illustrates an Affinity transform applied to two functional features at the same time (Shellable Prism and Pocket).


Open the Transform.CATPart document.



  1. Click the Transform icon . The Transform dialog box is displayed.

    Set Transform type:  Affinity


  2. Select Features to transform: Shellable Prism.1 and Pocket.1.

  3. Select Origin: Select Point.1

  4. Select XY Plane: Select xy plane

  5. Select X axis: Select X Axis using RMB

  6. Enter X=0.5, Y=3, Z=2 for Ratios.

  7. Click OK.