Modeling > Evaluate geometry > 
Judge or evaluate curve or surface quality
 
 
 

Describes the tools and display modes available to check the quality (continuity, smoothness, appearance) of your model.

Show curve curvature

Shows the amount of curvature at sample points along the curve, as well as other qualitative measures of the curve.

Add a curvature comb to a curve

  1. Choose Locators > Curve curvature.
  2. Click the curve you want to attach the curvature comb to.
  3. You can drag the mouse to change properties of the curvature comb:
    • Drag the to change the scale of the quills.
    • Drag the to change the sampling density of the comb.
      NoteIn orthographic windows, the curve curvature comb displays the curvature of a curve based on the planar projection of the curve that appears in that window. In perspective windows, the curve curvature comb displays the curvature of the 3D curve.

What if...?

I want the comb plots on all the curves to use the same scale

  1. Choose Locators > Curve curvature r.
  2. Turn off Auto Scale.
  3. Enter the scale factor in the Scale Value field.

The comb plot doesn’t update as I move CVs?

Choose Preferences > Performance options. In the Expression Updates section, turn on During Transform.

I need to change the curvature of a curve?

There are many ways you can modify a curve when you are trying to fix curvature problems:

I’m looking for a specific range of curvature values?

Choose Windows > Information > Information window and change the color ranges so that the values you are looking for are drawn in one color.

View or change the properties of objects and locators

Edit a label or measurement object

I want a series of curvature plots across a surface?

I want to see a plot of the radius values instead of curvature?

Choose Windows > Information > Information window and use the Plot Value option to change what the comb plot measures.

View or change the properties of objects and locators

Edit a label or measurement object

NoteCurve curvature options available in the Information window are also available in the Curve curvature option window if you want to change the values for all objects on which the tool operates.

Find curve problems using the curve curvature plot

How to use the curvature comb plot created by the Curve curvature tool to find problems on curves.

Show curve curvature

View or change the properties of objects and locators

Find inflection points

Turn on the Inflection Points option in the Information window. Inflection points are marked approximately with blue arrows. To find the exact inflection point, zoom in to the point where the comb outline crosses the curve.

What are inflection points?

Inflection points, also called ogees, are the points on the curve where the curvature changes direction.

Measure torsion

Turn on the Torsion option in the Information window to plot secondary quills showing the torsion.

What is torsion?

Torsion is the amount the curve bends out of the plane of curvature.

Find tangent discontinuities

Tangent discontinuities appear as two separate Unit Normal quills originating from the same point on the curve but pointing in different directions.

The telltale quills are always at an edit point. To see them clearly, set the Plot value option to Unit Normal in the Information window, and increase the Samples density to have at least 2 samples per span.

Make sure the Scale is high enough to tell whether there is more than one quill.

What are tangent discontinuities?

Tangent discontinues occur when two curves are not properly aligned. It can also happen at a , or because of .

Find curvature discontinuities

Curvature discontinuities appear as sudden steps in the outline of the curvature comb. You will need to use a high sampling rate to detect curvature discontinuities.

What are curvature discontinuities?

Curvature discontinuities between curves occur when two curves do not have the same curvature at their end, or because of multiplicity. The curve join may be smooth, but the curvature values do not change smoothly.

Show the minimum and maximum curvature on a surface

Labels the points on a surface with the minimum and maximum curvature values.

Set up the Min/max curvature tool

  1. Choose Evaluate > Min/max curvature r.
  2. Set the Mode option to Active.
  3. Click Save.

Show the minimum and maximum curvature values

  1. Pick the surface(s) you want to measure.
    NoteIf you pick more than one surface, the minimum and maximum are calculated over all the surfaces, not each surface individually.
  2. Choose Evaluate > Min/max curvature.

    The tool highlights the points of minimum and maximum curvature on the surfaces, and opens a window showing detailed information.

Check the deviation and continuity on surface edges

Use the Surface continuity tool to check the deviation and continuity along shared edges of surfaces.

Check the continuity between surfaces

  1. Pick the surfaces you want to check.
  2. Choose Evaluate > Continuity > Surface continuity.

    The tool displays symbols along the shared edges representing the continuity and deviation at each sampling point.

    TipTo get a complete review of the deviation and continuity set all options on; Locator Persistence, Show Max. Labels, Check interior, Show Edge Labels, and Show Comb.
    NoteThe calculation can take a long time for very complex models. To cancel the check, press .

How do I read the symbolic display?

Line style Meaning
Pale green, dotted. Edge with no adjacent surface, or an adjacent surface that is not selected.Hold and click a surface to select it.
Bright green Selected isoparametric curve with achieved continuity.
Dark green Isoparametric curve with achieved continuity.
Yellow Selected isoparametric curve with continuity break.
Red Isoparametric curve with continuity break.
Symbol Meaning
Cross Requested continuity achieved.
T Tangent/normal break.
C Curvature break.
O Gap in the common edge (think of the “O” as a hole).
Blue symbol Minimum measured deviation. (Not shown if minimum deviation is 0.)
Red symbol Maximum measured deviation.

These colors may be different if you have changed the interface color preferences.

  1. Do any of the following:
    • Click an edge to add it to or remove it from the check. Hold and click a surface to add it or remove it.
    • Drag the on empty space to change the scale of any active deviation comb plots.
    • Drag the on empty space to change the sampling density.
    • -click an edge to switch it between deviation comb and symbol display.
    • Drag the along an edge to show detailed numeric information on the points under the mouse pointer.
    • Open the prompt-line history window to see any messages the tool printed about continuity and deviation between the surfaces.

What if...?

I want the comb plots on all the surfaces to use the same scale

  1. Choose Evaluate > Continuity > Surface continuity r
  2. Turn on Show Edge Labels, turn on Show Combs, and turn off Auto Scale.
  3. Enter the scale factors for Positional, Tangent, and Curvature deviation combs respectively in the three Scale fields.

I want to change the tolerances?

Choose Preferences > Construction Options and open the Tolerances and Continuity sections.

The calculation takes too long?

Choose Evaluate > Continuity > Surface continuity p and increase the Distance Between Checks setting to make the tool calculate fewer sample points.

Measure the deviation between two objects

Use the tools in the Locators > Deviation sub-palette to show comb plots measuring the deviation between objects.

Add a deviation comb plot between two objects

TipRemember that for “curves” you can use surface edges, trim edges, isoparametric curves, and curves-on-surface in addition to free curves.
  1. Choose the appropriate tool for the object types you want to compare:
  2. Select the two objects. You must select the objects in the order specified by the tool name. For example, in MinMax Curve-Surface deviation, select a curve, followed by a surface.
    NoteIf more than one object are under the cursor, the appears, allowing you to select the correct object.
  3. Do any of the following:
    • Drag the to change the scale of the quills.
    • Drag the to change the density of the quills.
    • Drag a label to move it.
      NoteThe MinMax Mesh-Surface Deviation tool does not display a comb or mean deviation value.

View the exact numeric values from a deviation locator

Choose Windows > Information > Deviation table.

Measure deviations using the Show deviations tool in the Modeling control panel

This icon lets you create and change deviation combs.

To create deviation combs

  1. Pick all the scan lines/section data sets (curves)/polygonal data sets and surfaces between which you want to calculate the deviation.
  2. Click the Show deviations tool at the bottom of the Modeling control panel.
  3. Adjust the options in the Deviation section of the Modeling control panel.

To quickly display the deviation comb

  1. Pick either the surface or the scan-line/section data (curve)/polygonal data which contains the deviation comb.
  2. Click the Deviation button in the Display area of the Control panel.

To quickly hide the deviation comb

  1. Pick either the surface or the scan-line/section data (curve)/polygonal data which contains the deviation comb.
  2. Click the Deviation button in the Display area of the Control panel.

To delete deviation combs

  1. Click the Pick > Locator tool, and then click on the deviation comb. This will highlight the deviation comb.
  2. Select Delete > Del active to delete this active locator.

To create minimum and maximum deviation locators between a surface and a mesh

  1. Pick a mesh and surface between which you want to calculate the minimum and maximum deviation.
  2. Click the Show deviations tool at the bottom of the Modeling control panel.
  3. Turn the Min. and Max. options on or off in the Deviation section of the Modeling control panel.

Create or view cross sections

Creates visual or real cross section lines on the selected surfaces and meshes, corresponding to the axes or picked section data, or radially from a curve.

The different types of cross-sections

Axis Aligned

Cross sections are created in the X,Y or Z planes with a regular step size starting from the origin. For example, with a step size of 2.5 cm, the cross section specs are created at -2.5, 0.0, 2.5, 5.0... and so on.

When the Auto Range option is turned on (default), the cross sections are shown over the entire surface. Otherwise, you must explicitly set the range over which the cross sections should be displayed.

Picked Reference

Cross sections are created at the intersection between the geometry and selected section data or construction planes.

NoteSection data can be created from degree 1 NURBS by using the crvToSection plug-in.
Radial

Cross-sections are created based on a driving curve you specify, and the Num Planes option. Points, equally spaced by arc length, are placed on the curve to correspond to the number of sections. A plane is then defined perpendicular to the curve’s tangent at each of these points. The cross-sections are created where the planes intersect the geometry.

The driving curve can be a free curve, a curve-on-surface, or a surface edge or isoparm.

Cross sections can be created by using the Evaluate > Cross section tool, or by using the Cross Section Control tab in the Modeling control panel.

When using Evaluate > Cross section, you have to adjust the cross section options every time you select new objects. The cross sections are created as real geometry (NURBS or section data).

With the Cross Section Control tab, you can define groups of cross sections with specific characteristics, apply them to any geometry at any time, and even save them with your model. However, these cross sections are “visual” only (no geometry is created).

NoteVisual cross sections can be transformed into geometry by setting Section Type to NURBS from Visual in the Evaluate > Cross sectionEvaluate > Cross section option window, and clicking Go.

To create Axis Aligned (X, Y, Z) geometry cross sections

  1. Choose Evaluate > Cross section - r, to open the option window.
  2. Set Section Type to Axis Aligned.
  3. Put a check mark in Create Section Data to create section data. Remove the check mark to create NURBS geometry.
  4. Select the surface(s) or mesh(es) on which you want to create cross sections. These can also be selected before entering the tool.
  5. Press the Go button in the bottom right corner of your view window.

    Purple cross sections appear on the geometry, corresponding to the parameters set in the option window.

  6. Change the step size, range or other parameters in the option window if desired, and press Go to update the cross-sections.

    See Evaluate > Cross section for option details.

To create Picked Reference geometry cross sections

  1. Choose Evaluate > Cross section - p, to open the option window.
  2. Set Section Type to Picked Reference.
  3. Put a check mark in Create Section Data to create section data. Remove the check mark to create NURBS geometry.
  4. Select the surface(s) or mesh(es) on which you want to create cross sections. These can also be selected before entering the tool.
  5. Press the Go button in the bottom right corner of your view window.
  6. Select the construction plane(s) and/or section data.
  7. Press Go.

    Cross sections appear on the geometry, where it intersects the selected planes/section data.

    NoteIf creating section data cross sections, you can use Curve Edit > Sort sections to sort out your cross sections into different layers, according to the plane they lie in (X, Y, Z or Other).

To create Radial geometry cross sections

  1. Choose Evaluate > Cross section - r, to open the option window.
  2. Set Section Type to Radial.
  3. Put a check mark in Create Section Data to create section data. Remove the check mark to create NURBS geometry.
  4. Select the surface(s) or mesh(es) on which you want to create cross sections. These can also be selected before entering the tool.
  5. Press the Go button in the bottom right corner of your view window.
  6. Select the driving curve(s). More than one curve can be selected if all curves are tangent continuous. Clicking a selected curve deselects it.
    NoteIf Chain Select is turned on, you can select a group of tangent continuous curves all at once.
  7. Use the Number of Planes slider in the option window to adjust the number of radial sections. The minimum is 2.

    Small planes, equally spaced by arc length, are displayed on the curve(s), corresponding to the number of sections. The planes are perpendicular to the curve’s tangent at each location.

  8. Press Go.

    Cross sections appear on the geometry, where it intersects the planes.

To use default cross sections from the Control Panel

  1. Pick the surfaces on which you want to display/remove cross sections.
  2. In the Cross Section Control options of the Modeling control panel, click the X, Y, or Z preset cross section groups in the list.

    NoteYou can select more than one set of cross sections by clicking down while holding the or key.
  3. Double-click the group’s name to open the option window from where you can change the step size or range.

    See Cross Section Control window for details.

    These cross-sections apply to your entire Studio session.

To create and name a group of visual cross sections

  1. Pick the surfaces on which you want to display/remove cross sections.
  2. Click the New button in the Cross Section Control options of the Modeling control panel. From the pop-up menu choose Axis Aligned, Picked Reference, or Radial, depending on the type of cross-sections you want to create.
    NoteIf you choose Picked Reference, you need to have some section data or construction plane already selected. If you choose Radial, you will be prompted to select a curve.

    The cross section appear in green and the Cross Section Control window opens.

  3. Delete the default name in the Name text field, and type in a new name. Hit .

    The new name for the cross section group is displayed in the control panel.

    These user-defined cross-sections can be applied to any surface(s) or meshe(s) and are saved with your model.

  4. Check on Store as default if you want the cross section group to become a new default (like the preset X, Y, and Z groups).

    The cross section group appears in gray in the Control Panel. It can then be applied to obejcts in other stages.

    The default group will remain in the Control Panel even after you exit and re-launch AliasStudio. To delete it, you must select it and press the Delete button.

To change the visual cross section settings

You can only modify the settings for Axis Aligned cross sections. In the Cross Section Control window, do the following:

  1. Click the X, Y and Z buttons of the axis along which you want the cross sections displayed or removed.
  2. Control spacing between cross section lines along the X, Y and Z axes by entering different values in the Step fields. Increase line density by decreasing step values.

To create and change a deviation comb on a visual cross section

  1. Click the Curvature ON/OFF checkbox in the Cross Section Control window so that a check mark appears.

    The deviation combs appear in green on the model.

    A Curvature Scale slider and Lock Curvature Scale checkbox appear in the Cross Section Control window.

  2. Slide the Curvature Scale slider to scale the length of the curvature combs.
  3. Click the Lock Curvature Scale checkbox to prevent any accidental modification of the curvature scale when using the global Comb Scale slider from the Control Panel. (See Control Panel > Curvature).
    NoteCurvature plots are not available on mesh cross sections.

Tip

To show or hide curvature plots on existing visual cross sections

  1. Pick a surface on which you have created cross sections.
  2. Click the Curvature ON/OFF checkbox in the Cross Section Control window so that the check mark disappears.

Drag dynamic cross sections through surfaces

Lets you move a plane through a surface or mesh to show cross sections dynamically.

Drag cross sections through surfaces

  1. Pick the surfaces or meshes you want to examine.
  2. Choose Evaluate > Dynamic Section r.

    A sectioning plane appears, at the geometric center of the object(s).

  3. Set the Number of Planes (number of sections) and Step Size (spacing between sections) in the option box.
  4. Use the manipulator to orient the sectioning plane (see below).

    The sections appear as red lines and update as the plane is moved/rotated.

  5. Do any of the following:
    • Use the manipulator to move the sectioning plane through the surfaces.
    • Select an existing construction plane to use as the base sectioning plane.
    • Press the Geom button to create free curves from the cross section(s).
    • Press the Create Planes button to create construction planes corresponding to the sectioning planes.
    • Press the Curvature On button to show a curvature comb plot on the section(s). To change the scale of the comb plot, adjust the Curvature Scale setting.
    • Turn on Visual Clip or Flip in the option box, to see only the part of the model in front or behind the sectioning plane.
    • Turn on Persistent Sections in the option box for the sections to remain visible after exiting the tool.
      NoteIf creating true geometry cross sections with the Geom button, you can use Curve Edit > Sort sections to sort out your cross sections into different layers, according to the plane they lie in (X, Y, Z or Other). This grouping is useful for manipulating cross section data.

How do I use the manipulator?

Remove persistent sections

If the Persistent Sections option was turned on, the sections will remain after exiting the tool.

Use the Clear button in the Cross Section tab of the Control Panel to remove them.

Check continuity between curves

Check whether two curve endpoints have position, tangent, or curvature continuity.

Show the continuity between two curves

  1. Choose Evaluate > Continuity > Curve continuity.
  2. Click the intersection of two curves.
    • If the curves are not positional (the distance between the curve endpoints is greater than the Maximum Gap Distance tolerance), AliasStudio draws a line between the endpoints and shows the distance.
    • If the curves are not tangent continuous, AliasStudio draws lines showing the tangents of each curve and shows the angle between the tangents.
    • You can drag left or right to change the length of the tangent lines (if your curves are not tangent continuous).
    • If the Curvature option is on, and the curves are tangent continuous, AliasStudio shows another locator pointing to the intersection, with the curvature deviation value.

What if...?

I can’t see the difference between the two tangent lines clearly?

Drag right, or choose Evaluate > Continuity > Curve continuity r and use the options to increase the scale of the tangent lines.

I want to change the maximum gap distance tolerance?

Choose Preferences > Construction Options and set the Maximum Gap Distance option.

Create curves on surface from evaluation data

Create curves-on-surface corresponding to highlights, iso-curvature lines, contours, horizon lines, or parting lines.

Create curves on surface from highlight data

To create curves-on-surface corresponding to highlight lines:

  1. Pick the surfaces.
  2. Choose Evaluate > Surface Evaluate > Highlights r.
  3. Click the Go button.
  4. Use the manipulator to change the position and orientation of the light.
  5. Set the following options in the option window:
    • The Number of Lights you want to create highlights from.
    • The Light Spacing (if there is more than one light) or the Light Width (if there is only one light).
    • Set the Subdivision option from 1 to 6. The higher the number, the more precise the result.

    The curves on surface update as the light and option values are modified.

  6. Click on additional surfaces to evaluate them, or deselect active surfaces.

Create curves on surface from curvature data

To create curves-on-surface along lines of constant curvature:

  1. Pick the surfaces.
  2. Choose Evaluate > Surface Evaluate > Curvature p.
  3. Set the following options in the option window:
    • The Curvature Type.
    • The Curvature Value at which you want to create curves on surface. For example, enter 0 to create curves-on-surface along inflection lines.
    • Set the Subdivision option from 1 to 6. The higher the number, the more precise the result.

    The curves on surface update as the option values are modified.

  4. Click on additional surfaces to evaluate them, or deselect active surfaces.

Create curves on surface from contour data

To create a curve-on-surface where the surface intersects a plane:

  1. Pick the surfaces.
  2. Choose Evaluate > Surface Evaluate > Contour.
  3. Click the Go button.
  4. Use the manipulator to change the position and orientation of the plane.

    The curve on surface updates as the plane is modified.

  5. Click on additional surfaces to evaluate them, or deselect active surfaces.

Create curves on surface from horizon data

To create a curve-on-surface across the horizon as seen from a certain angle:

  1. Pick the surfaces.
  2. Choose Evaluate > Surface Evaluate > Horizon.
  3. Click the Go button.
  4. Use the manipulator to change the position of the horizon origin.

    The curve on surface updates as the horizon is modified.

    NoteIf the horizon you set does not cross the surfaces, the tool will not create any curves on surface
  5. Click on additional surfaces to evaluate them, or deselect active surfaces.

Create curves on surface from parting line data

To create a curve-on-surface along parting lines given a pull direction:

  1. Pick the surfaces.
  2. Choose Evaluate > Parting line.
  3. Click the Go button.
  4. Use the manipulator to change the pull direction.

    The curve on surface updates as the pull direction is modified.

  5. Set the following options in the option window:
    • The Draft Angle.
    • Set the Subdivision option from 1 to 6. The higher the number, the more precise the result.
  6. Click on additional surfaces to evaluate them, or deselect active surfaces.

Shade surfaces with color

Use the Diagnostic Shading tools in the Modeling Control Panel to assess the quality of surfaces.

Watch the Evaluate surfaces movie.

Shade the picked surfaces with color

Shade the picked surfaces with random colors

Unshade the picked surfaces

Adjust the options of a shading mode

Set the shaded color

  1. Pick the surface or surfaces.

    Click the small triangle at the bottom of the Diagnostic Shading panel to show the options.

  2. Click the color swatch to show to color editor.

How does setting the color in Multi-color mode affect objects?

What if...?

I don’t know where the Diagnostic Shading panel is?

Shade a surface with a curvature or other map

Shades the picked surfaces with a color map showing areas of high and low curvature.

Shade the picked surfaces with a curvature map

  1. Click the button in the Diagnostic Shading panel.
  2. Click the small triangle at the bottom of the Diagnostic Shading panel to show the shading options.

  3. Choose the type of curvature to show from the Curvature Evaluation Type menu.

What if...?

I don’t know where the Diagnostic Shading panel is?

Shade a surface with zebra stripes

Shades the picked surfaces with a zebra stripe pattern allowing you to see discontinuities and visualize the shape of the surface.

Shade the picked surfaces with zebra stripes

  1. Click the button in the Diagnostic Shading panel.
  2. Click the small triangle at the bottom of the Diagnostic Shading panel to show the shading options.

  3. Do any of the following:
    • Choose the direction of the stripes (horizontal or vertical).
    • Use the Repeats slider to increase or decrease the number of stripes.
    • Normally the highlights are relative to the camera, so you can see them “roll” over the surface as you tumble. Turn on the Lock Texture option to lock the texture to the surface.

What if...?

I don’t know where the Diagnostic Shading panel is?

Show iso-angle lines on a surface

Iso-angle projects onto the surfaces from a certain angle, and creates shaded bands and/or lines where the surface is at right angles to the projection direction.

Create iso-angle display shading/lines

  1. Pick the surfaces.
  2. Choose Evaluate > IsoAngle r.
  3. Choose whether to shade the surfaces and/or create lines.
  4. Choose whether to show a single or multiple bands.
  5. Use the manipulator to set the direction of projection.

    If the manipulator is not visible, click the Show Manipulator button.

    TipIt is often helpful to use multiple bands as you position the manipulator to give you more feedback, then switch to fewer or a single band.

The iso-angle shader is now also available from the Diagnostic Shading Panel. Some option are provided in the panel. Others (such as number of bands and vector direction) must be accessed from the Evaluate > IsoAngle option box.

NoteYou cannot create iso-angle visual curves from Diagnostic Shading.

What if...?

I don’t know where the Diagnostic Shading panel is?

Shade a surface with its draft angles

Shades the picked surfaces with a color map showing areas in and out of draft, for checking mold manufacturability.

This shading mode shows you which parts of a surface are in-draft and out-of-draft for a specified pull vector and draft angle. In-draft points are shaded blue, out-of-draft points are shaded red. You can also display a tolerance region in pink.

Shade the picked surfaces with a draft angle map

  1. Click the button in the Diagnostic Shading panel.
  2. Click the small triangle at the bottom of the Diagnostic Shading panel to show the shading options.

  3. In the Type pop-up menu, choose Draft Angle.
  4. Choose whether to specify the pull angle as a rotation (from the normal “up” direction) or as a vector, then enter the X, Y, and Z values.
    NoteIf you want to use an existing vector or plane to specify the pull vector, pick it, then click the Update From Selection button. This automatically sets the X, Y, Z coordinates to the correct values in the panel.
  5. Do any of the following:
    • Set the draft angle.
    • To show a tolerance region between in-draft and out-of-draft, set the tolerance angle.
    • Adjust the transparency of the shader.
      TipYou can create a curve-on-surface along the parting line using Evaluate > Parting line in the Palette.

      SeeCreate curves on surface from evaluation datafor more information.

What if...?

I don’t know where the Diagnostic Shading panel is?

I don’t know what vector values I need?

1. Use the Construction > Vector tool to create a reference vector, and point it in the direction you want.

2. Pick the reference vector and click the Update From Selection button under the Draft Angle options in the Control Panel. (If you pick a plane instead, the direction perpendicular to the plane is used.)

The X, Y, and Z coordinates of the vector are automatically set.

I don’t know what pull direction, draft angle, in-draft, out-of-draft, mean?

Some manufacturing processes, like injection molding, need you to design molds. When a mold is used it is pulled away from the finished part along a pull direction.

Angle-to-pull is the angle between the surface tangent plane at a surface point and the pull vector. When the angle-to-pull is 0 degrees, the pull vector is parallel to the surface tangent plane at that point. When the angle-to-pull is 90 degrees, the pull vector is normal to the surface.

Most manufacturing processes require that the angle-to-pull for a molded surface be greater than some angle, for example 1 degree, or else the molded part will not separate from the mold. This angle is the draft angle.

When the angle-to-pull is less than the draft angle, the surface point is out-of-draft. When the angle-to-pull is more than the draft angle, the surface point is in-draft.

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 r.

    In the Check Model Settings option 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.
  2. Choose what types of problems or conditions you want to check for. See Evaluate > Check model for more information on the different checks.
    NoteA 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 Unigraphics, Catia, Pro/E, etc.

    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.

    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 to help 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 to help 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 Settings option window.
    NoteTolerances for these continuity checks are found in the Tolerance : Continuity section of Preferences > Construction Options.
    NoteFor the G0 test to be successful, you must 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 option in the Check Model Settings option window.

    The Topology Distance tolerance (Tolerances:Topology section under Preferences > Construction Options) is used to determine which surfaces are topologically adjacent and should have their normals checked as a group.

  2. Click Check.

    The report window displays a column titled Flipped Normal to help 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 option in 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.

NoteMultiple 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.
    NoteFor Indistinct Knots, the value is a tolerance in parameter space. For Tiny Spans, the value is a distance expressed in current linear units (e.g. 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.
    NoteSurfaces 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

Prepare a model for import into CAD systems

Use Product Data Quality checks in Evaluate > Check model to ensure that your model meets minimum geometric requirements for import into a CAD system.

See Check objects for modeling problems for more information.

In order to achieve the desired results, some checks should be executed before others. As a general rule, the checks for duplicate geometry (Copies and Duplicates Within Tolerance) should be applied first, since duplicate or embedded geometry can falsify the results of continuity checks.

Below is a recommended workflow ideally suited to prepare the following model for import into ProEngineer.

Choose the correct Construction Presets

  1. In the Construction Presets section under Preferences > Construction Options, choose Pro-Engineer.

    All the construction tolerances are set to the proper Pro-Engineer values.

The above image shows the Check Model options on the left, and the Construction options (set for ProEngineer) on the right.

Check the model for duplicate geometry

This check enables you to find both duplicate and embedded curves and surfaces in your model. Embedded geometry consist of curves and surfaces that duplicate parts of larger objects.

  1. Set Duplicate Geometry to Duplicates Within Tolerance in the Preferences > Construction Options option window.
  2. Adjust the tolerance in the Duplicate Tolerance field.

    This value represents the maximum distance allowed between two surfaces (or curves) for them to be considered duplicates. It is measured along the geometry’s normal.

  3. Click the Check button.

    The spreadsheet window appears, listing the geometry that failed the check on the left-hand side. This geometry is either a duplicate of, or embedded in, the geometry shown in the corresponding columns (labeled Tolerance Duplicates and Embedded In). The names of curves or surfaces that are duplicates of each other are all prefixed by the same number.

  4. Selects a row in the spreadsheet.

    The corresponding geometry is highlighted while you press the mouse button. To have the geometry selected permanently, choose Pick > Pick Selected in the spreadsheet menu.

    Our example shows one duplicate and one embedded surface.

    To select the duplicate, choose Pick > Pick Tolerance Duplicates in the spreadsheet menu.

  5. Delete the duplicate and embedded geometry.
NoteIf you are not concerned about embedded geometry and only want to find exact duplicates, set Duplicate Geometry to Copies instead. Use Pick > Pick Copies in the spreadsheet menu to select them.

Check the model for continuity between curves and surfaces

Now that the redundant geometry has been removed, we can proceed with the continuity check.

  1. Choose the Tangent Angle - G1 option in the Preferences > Construction Options option window.

    Notice that the check for positional continuity (Max. Gap Distance) was turned on automatically, since geometry must pass the positional continuity test before tangency can be checked. Similarly if the Curvature check was selected, the tangency and positional checks would be turned on automatically.

    NoteAll three continuity checks use the continuity tolerances from Preferences > Construction Options.
  2. Click the Check button.

    The spreadsheet window appears, listing the geometry that failed the checks on the left-hand side. The G0 and G1 columns display a mark showing which continuity check failed.

    In the viewing window, discontinuous boundaries are highlighted, and the letters P, T or C indicate the type of discontinuity (Positional, Tangent or Curvature).

Check the model for short edges

This check identifies surfaces with short edges. Short edges are surface boundaries that are legal in AliasStudio, but may be problematic if used in certain operations, or illegal in other systems into which the model will be imported.

For example, the Offset tool could reduce a 0.1 mm boundary to 0.0 mm, thereby creating a degenerate surface not valid to be passed down to other systems.

As well, if a surface boundary is 0.01 mm in length and you are sending it to a CAD system where the tolerance for coincident points is 0.02 mm, then this surface will not be a legal entity in the CAD system.

To identify short edges:

  1. Choose the Short Edges option in the Evaluate > Check model option window.
  2. Adjust the tolerance in the adjoining text field.

    This value represents the minimum length that a surface boundary must have to pass the check. All shorter edges will be reported.

  3. Click the Check button.

    The spreadsheet window appears, listing the geometry that failed the check on the left-hand side, and the number of short edges in the Short Edges column.

Check the model for uniformity of surface normals

The Normal Consistency check looks for geometry whose normal direction is different from the direction of the majority of the surfaces in the topology being checked. A topology is a group of surfaces whose boundaries are within the Topology Distance set in Preferences > Construction Options. These surfaces are considered to be adjacent to each other.

To find inconsistent normals:

  1. Choose the Normal Consistency option in the Evaluate > Check model option window.
  2. Click the Check button.

    The spreadsheet window appears, listing the geometry that failed the check on the left-hand side, with a mark in the Flipped Normal column.

    In the viewing window, inconsistent normals are shown as arrows with the letter “N”. In our example, one such surface has been identified.

  3. Click the surface name in the spreadsheet to see it more clearly.

    TipCheck model only identifies normal inconsistencies of individual surfaces. To get a complete picture of all the topologies in this model, use Object Edit > Dynamic Shape Modeling > Transformer Rig. To reverse normals, use Object edit > Fit b-spline.

Visualize the deviation between mesh-surface, surface-surface or mesh-mesh

How to show the deviation (distance) between a set of meshes and a set of NURBS surfaces as a colored error map on the surfaces. How to show the deviation (distance) between two sets of meshes or two sets of NURBS surfaces as a colored error map.

Objects in reference layers can be selected from within this tool.

Display a Mesh-to-Surface deviation error map

  1. Select the Evaluate > Deviation map tool
  2. Select one or more surfaces, then click the Accept button.
  3. Select one or more meshes, then click the Go button.

    The deviation error map appears on the surfaces and a color ramp (deviation ramp) is displayed.

Display a Surface-to-Surface deviation error map:

  1. Choose Evaluate > Deviation map.
  2. Select one or more surfaces.
  3. Press the Accept button.
  4. Press the Surfaces button.
  5. Select the second set of surfaces.
  6. Press the Go button.

    The deviation error map appears on the first set of surfaces and a color ramp (deviation ramp) is displayed.

Display a Mesh-to-Mesh deviation error map:

  1. Choose Evaluate > Deviation map.
  2. Press the Mesh button
  3. Select one or more meshes.
  4. Press the Accept button.
  5. Select the second set of meshes.
  6. Press the Go button.

    The deviation error map appears on the first set of meshes and a color ramp (deviation ramp) is displayed.

    NoteThe first set of meshes or surfaces can also be selected before entering the tool.

The color ramp

The color in the center of the ramp (green) identifies regions where the deviation is within an Acceptable Distance value. The colors at both ends of the ramp identify regions where the deviation is above a certain maximum value (Ramp Distance) in either direction. Between these two values, the surface displays intermediate colors as shown on the ramp.

Adjust the display of the color ramp

The color distribution on the ramp can be adjusted as follows:

  1. Double-click the tool to open the option box.

  2. Use the Acceptable Distance and Ramp Distance sliders to modify the tolerance bands in the color scale.

    The deviation error map on the surface(s) updates.

    NoteThe Ramp Distance is the maximum distance between surface and mesh shown on the color ramp. It should be kept larger than the Acceptable Distance.
  3. Turn on the Absolute Value Ramp option if you are not concerned about the direction of the deviation and only want to see absolute deviation values.
  4. Turn on the Use Bands option if you want the ramp to display solid bands of color instead of slowly varying colors.

The deviation map

The deviation error map is persistent during tumbling or other view manipulation. Modifications to the geometry cause the error map to update.

To remove the map, select the Shading Off button in the Diagnostic Shading section of the Control Panel, or any of the other Diagnostic Shading buttons.

Make quick measurements on shaded models

How to quickly measure distances on shaded models using Evaluate > Dynamic Measurement. This tool also works on wireframe models.

To create a dynamic measurement

  1. Choose Evaluate > Dynamic Measurement.
  2. Click anywhere in an orthographic or perspective window to define the first point. Hold down the mouse button and drag to move the point around.

    A cross-hair appears.

  3. Click somewhere else in the same window to define the second point. Hold down the mouse button and drag to move the point around.

    A ruler appears between the two points and the distance between the points is displayed (in the current linear units).

    NoteClick with the middle or right mouse button, to align the second point horizontally or vertically (respectively) with the first point.
  4. Repeat the steps above to create another measurement in the same window or another orthographic window.
    NoteThe measurements are not persistent and disappear as soon as you select another tool.

To modify the start and end points of a dynamic measurement

  1. Roll the mouse over the start or end point.

    The point turns yellow.

  2. Click and drag the point to another position. The middle and right mouse buttons move the point horizontally and vertically respectively.

To move the measurement

  1. Roll the mouse over the ruler.

    The ruler turns yellow.

  2. Click and drag to translate the ruler. The middle and right mouse buttons move the ruler horizontally and vertically respectively.

To anchor a measurement

  1. Move the ruler so the start point is on top of a wireframe, shaded object, or locator.

    The start point turns into a square to indicate that it is attached to the object. The ruler becomes lavender and remains parallel to the view plane.

  2. To free the measurement from the object, just move the start point off it.

A measurement can be anchored in any view, including the Perspective view.

To remove all measurements

All measurements disappear as soon as you choose another tool. However, if you need to remove them while still in the Dynamic Measurement tool, press the Clear button at the bottom of the window.

Using the tool in the Perspective window

Dynamic Measurement works differently in the Perspective window depending if the mode is truly perspective, or if it is set to orthographic. (Hold the Alt and Shift key and uncheck Perspective in the Viewing Panel). The behavior is also different depending if the measurement is anchored or not. See the table below.

  Persp Ortho
Anchor The start point of the ruler stays attached to the object when you change the view. The ruler is drawn in lavender and always faces you.
Fixed Invalid. Measurement displays (in red) so you can anchor it. If you pan the view or rotate the view, the measurement appears to be anchored to the screen (it does not move relative to the modeling window). When you zoom the camera, the measurement appears to zoom with the model.

Limitations

Unlike Locators, Dynamic measurements are not designed to be saved with a model or to persist beyond the use of the tool. As well, they cannot be truly snapped to grid or geometry, only temporarily anchored so they follow the motions of the object.

Dynamic measurements work (that is, they can be anchored) even when a model wireframe is toggled off (for example, in a modeling window where only hardware shade appears). Snapping does not work when the model wireframe is toggled off.