Check objects for modeling problems
 
 
 

The Check model tool lists possible problems with your model that can affect data transfer to other software packages.

Show a list of modeling problems

  1. Choose Evaluate > Check Model .

    In the Check Model Options window:

    • Choose whether to check only Surfaces, only Curves or Both.
    • Choose whether to check All objects, All Visible objects, or the picked (Active) objects.
    • Choose whether to list only objects with problems (Only Errors) or all objects.
    • Choose a set of construction tolerances from the Use Construction Preset drop down menu, to use in the model check calculations.
      Note

      These correspond to the Construction Presets available from Preferences > Construction Options. Select Use Current Tolerances to use whatever preset is already selected in the Construction Options window (indicated by a white arrow).

  2. Choose what types of problems or conditions you want to check for. See Evaluate > Check Model for more information on the different checks.
    Note

    A special section called Product Data Quality contains checks that apply specifically to making a model compliant with the VDA-4955 and SASIG PDQ guidelines, so that it can be better handled by other packages such as NX, Catia, Pro/E, and so on.

    See Prepare a model for import into CAD systems for more information.

  3. Click Check.

    The resulting check data is displayed in a window organized as a table. Geometry that fails a given check will display a mark in the corresponding column.

    See View the data in the report window

Check for duplicate curves or surfaces

You can check for both copies (exact duplicates), and duplicates within a given tolerance. Copies have the same CVs, same knots, and same degree (such as geometry created with Edit > Copy and Edit > Paste ).

Checking for copies

This is the fastest of the two methods.

  1. Set Duplicate Geometry to Copies in the Check Model Settings option window.
  2. Click Check.

    The report window displays a column titled Copies tohelp you identify all the copies. If Report is set to All, the original geometry is identified by the word “Original” in the column.

Checking for duplicates within a given tolerance

  1. Set Duplicate Geometry to Duplicate Within Tolerance in the Check Model Settings option window.
  2. Adjust the Duplicate Tolerance value. Geometry that is a duplicate of, or embedded into other geometry within this tolerance will be reported.
  3. Click Check.

    The report window displays two columns titled Embedded In and Tolerance Duplicates tohelp you identify all the duplicates. The duplicates prefixed by “0” in the Tolerance Duplicates column are considered the originals.

Check continuity between curves or surfaces

  1. Turn on the Max. Gap Distance - G0, Tangent Angle - G1 or Curvature - G2 option in the Check Model Options window.
    Note

    Tolerances for these continuity checks are found in the Tolerance:Continuity section of Preferences > Construction Options and correspond to the construction preset selected in the Check Model Options window.

    Note

    For the G0 test to be successful, you must also ensure that the Topology Distance tolerance (Tolerances:Topology section under Preferences > Construction Options) is larger than the Maximum Gap Distance.

  2. Click Check.

    The report window displays columns titled G0, G1 and G2 with marks indicating failure. If geometry fails the G0 test, higher continuity tests for G1 and G2 will not be performed. Similarly, if geometry fails the G1 test, continuity test for G2 will not be performed

    In the viewing window, the boundaries that failed the continuity tests are shown as thick yellow lines with a letter identifying the type of discontinuity (P = positional, T = tangent, C = curvature).

What do Report Parameters do?

The report parameters are tolerance values above which certain types of checks will not be executed.

Check consistency of orientation of surface normals

  1. Turn on the Normal Consistency optionin the Check Model Options window.
  2. Note

    The Topology Distance tolerance is used to determine which surfaces are topologically adjacent and should have their normals checked as a group. It is found in the Tolerances:Topology section of Preferences > Construction Options and corresponds to the construction preset selected in the Check Model Options window.

  3. Click Check.

    The report window displays a column titled Flipped Normal tohelp you identify the surfaces with inconsistent normal directions. In the viewing window, the inconsistent normals are shown as white arrows.

Check for maximum degree

This check enables you to identify curves and surfaces that exceed a user-defined degree. The default value for maximum degree is 7.

  1. In the Check Model Settings option window, set the Check option to Surfaces, Curves or Both.
  2. Turn on the Maximum Degree option.
  3. Adjust the value in the text field next to the option selection box. Curves and/or surfaces that have degree larger than this value will be reported.
  4. Click Check.

    The report window displays a column titled Degree which contains the degree of curves and/or surfaces that failed the test.

Check for minimum radius of curvature

This check enable you to identify surfaces (including trimmed surfaces) that exceed a user-defined curvature radius.

  1. Turn on the Minimum Radius of Curvature optionin the Check Model Settings option window.
  2. Adjust the tolerance value in the text field next to the option check box. Surfaces that have a radius of curvature smaller than this value (in any direction) will be reported.
  3. Click Check.

    The report window displays a column titled Min Radius of Curv which contains the minimum radius found on surfaces that failed the test.

Check for surface or planar curve waviness

This check enables you to identify surfaces or planar curves that have more than a certain number of inflections (change in curvature sign) per span (1 is the default) or over their entire length or width (3 is the default).

  1. Turn on the Surface or Planar Curve Waviness option in the Check Model Settings option window.
  2. Specify your criteria for waviness by changing the value next to the checkbox. This value represents the total number of inflections allowed over the length (or width) of the planar curve or surface for it to pass the test.
  3. If the Allowed Inflections Per Span option is turned on, you can adjust the corresponding value to add an extra waviness criterion. The check will fail if the planar curve or surface has more than the given number of inflections per span, or more than the given number of inflections overall (as specified in step 2).
  4. Click Check.

    The report window displays a column titled Waviness with marks indicating failure.

Check for short edges

This check enables you to identify curves and surface boundaries that are shorter than a user-defined value. This helps find geometry that may be problematic when used in certain operations, or may not be recognized as valid geometry in downstream CAD systems.

See Prepare a model for import into CAD systems for more information.

  1. In the Check Model Settings option window, set the Check option to Surfaces, Curves or Both.
  2. Verify that the Short Edges option is turned on.
  3. Adjust the value in the text field next to the option selection box. Curves that are shorter than this value and/or surface that have boundaries shorter than this value will be reported.
  4. Click Check.

    The report window displays a column titled Short Edges which contains the number of short edges on geometry that failed the test.

Check for non-planar curves

This check enables you to identify curves that are not planar. In the Check Model Settings option window, set the Check option to Curves or Both.

  1. Turn on the Non-Planar Curves option.
  2. Click Check.

    The report window displays a column titled Non-Planar Curve with marks indicating failure for the objects listed in the left-hand column.

Check for indistinct knots or tiny spans

This check enables you to identify curves and surfaces whose interior span/isoparm configuration (distance between adjacent isoparametric curves) results in knots being too close (indistinct knots), or in the segment or patch size being too small (tiny spans).

The indistinct knot criterion is violated if two adjacent knots are non-multiple (not exactly equal), but within a user supplied tolerance in the curve or surface parameter space.

Note

Multiple knots do not violate this criterion - a separate check already exists for finding curves and surfaces with multiple knots.

The tiny span criterion for the minimal size of NURBS segments is violated if the segment length (or the length of both opposing patch segments for surfaces) is smaller than a user supplied distance tolerance.

  1. Turn on the Indistinct Knots and/or the Tiny Spans option.
  2. Adjust the value in the field next to the option selection box.
    Note

    For Indistinct Knots, the value is a tolerance in parameter space. For Tiny Spans, the value is a distance expressed in current linear units (for example mm).

  3. Click Check.

    The report window displays columns titled Indistinct Knots and Tiny Spans which contain the number of occurences of indistinct knots and tiny spans respectively, in the geometry that failed the test.

Check for maximum number of spans

This check enables you to identify curves and surfaces that contain a number of spans exceeding a user-defined value.

  1. Turn on the Maximum Spans option.
  2. Adjust the value in the text field next to the option selection box. Curves and surfaces that exceed this number of spans will be reported.
    Note

    Surfaces will fail the check if the number of spans in either the U or V direction exceeds the given value.

  3. Click Check.

    The report window displays a column titled Spans which contains the number of spans in the geometry that failed the test.

Check for self-intersections

This check enables you to identify curves, surface boundaries, or trimmed surface boundaries that contain interior self-intersections. A self-intersection refers to the curve or surface boundary intersecting itself at one or more locations that are not both endpoints (see pictures below).

  1. Turn on the Curve or Surf-Boundary Self Intersect option.
  2. Click Check.

    The report window displays a column titled Self-Intersecting with marks indicating failure for the objects listed in the left-hand column.

Check for intersection of trim boundaries

This check enables you to identify trimmed surfaces containing boundaries that intersect other boundaries on the same surface, within a user-defined tolerance (see picture).

  1. Turn on the Trimmed-Surf Boundary Intersect option.
  2. Adjust the value in the text field next to the option selection box. Boundaries that intersect within this distance will be reported.
  3. Click Check.

    The report window displays a column titled Trim Bndy Intersect with marks indicating failure for the objects listed in the left-hand column.

View the data in the report window