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This task shows how to analyze the distance
between any two geometric elements, or between two sets of elements. |
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The different mapping analyses of the same surfaces cannot
be displayed simultaneously, even if you have set the mapping analyzes in
no show. You need to visualize them one after the
other. |
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This command is only available
with:
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When computing the distance
between two curves, there is no negative values possible as opposed to
when analyzing the distance between a surface and another element.
Indeed, surfaces present an orientation in all three space directions
whereas, in the case of planar curves for example, only two directions
are defined. Therefore the distance is always expressed with a positive
value when analyzing the distance between two curves.
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The element whose dimension is
the smallest (0 for points,1 for curves, 2 for surfaces for example) is
automatically discretized, if needed.
When selecting a set of elements, the system compares the greatest
dimension of all elements in each set, and discretizes the one with the
smallest dimension.
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When the computed distance
between two elements is less than the model resolution or any of the
following:
then the Distance Analysis
displays zero value for the computed distance. The precision is not
guaranteed for computed distance values less than the model precision.
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Open the
FreeStyle_Part_11.CATPart document. |
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Select Curve.1.
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Click Distance Analysis
in the Shape Analysis toolbar.
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The Distance dialog box appears, the
Source is selected in the Element box: |
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The Distance dialog box displays the
following options:
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Elements: Defines the
elements to be analyzed. To add or remove multiple elements in a set, use the
Ctrl key.
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Source: Defines the first set
of elements to be analyzed. The elements selected in the Source
box are discretized. The distance measurement is done using these
discrete points.
All the elements selected before running the command are considered in
the Source box.
Note: It is advised to define the elements with lowest dimension in
the Source elements box. For example, you need to select
curve as source element against a surface as target element.
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Target: Defines the second
set of elements to be analyzed. The discretized elements are
projected on the target element(s).
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Inverts the analysis computation: Swaps the elements selected
in the Source and Target fields.
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Projection Space: Defines the
preprocessing of the input elements used for the computation.
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No Projection Of Elements: Elements are not modified and the computation is done
between the initial elements.
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Projection in X direction: Projection
is done along the X-axis.The computation is done between the projection
of selected elements. This option is available only for analyzing distances between
curves.
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Projection in Y direction: Projection is done along the Y-axis.
The computation is done between the projection
of selected elements. This option is available only for analyzing distances between
curves.
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Projection in Z direction: Projection is done along the Z-axis.
The computation is done between the projection
of selected elements.This option is available only for analyzing distances between
curves.
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Projection in compass direction:
Projection according to the current orientation of the compass, the
computation is done between the projection of selected elements.
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Planar
distance: The distance is computed between a curve and the
intersection of the plane containing that curve. this option is only
available for
analyzing distances between a curve and a plane.
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Measurement Direction: Provides
options to define how set the direction used for the distance
computation.
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Normal
distance: The distance is computed according to the normal to
the other set of elements.
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Distance in X direction: The
distance is computed according to the X-axis.
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Distance in Y direction: The
distance is computed according to the Y-axis.
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Distance in Z direction: The
distance is computed according to the Z-axis
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Distance in compass direction:
The distance is computed according to the compass orientation.
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Relimitation:
Provides options to define the limiting points on a curve or a
surface.
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User max distance: Defines the maximum distance in absolute
value for computation.
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Automatic discretization points elimination: Delimits the set
of points of discretization to be taken into account for the
computation, in the case of a large set of points of discretization,
thus improving the performances.
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When
using the
Automatic
discretization
points elimination
option, a
mean plane
of the non-discretized
element is
computed.
If the points of discretization
are too
scattered
according to
this mean
plane, this
option may
not be able
to take into
account as
many points
as needed
for a
consistent
result such
as an incomplete
result (some
computed
areas are
not taken
into
account) or
no result.
In this
case, it is
best to
clear the
option. |
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Limits the descretized curve: Re-limits the discretized curve, this functionality is P2-only.
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Limits the non descretized curve: Re-limits the non discretized curve, this functionality is P2-only.
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Signed
value distance mode: In some cases the distance between the
discretized points and surfacic elements can be negative regarding the
topological normal of the surfacic element. In this mode the orientation
of the topological normal is taken into account.
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Discretization: Reduces or
increases the number of points of discretization from the set of
elements which are taken into account when computing the distance.
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The discretization option should be set
to a maximum (See Infrastructure User's Guide: Improving
Performances, the 3D Accuracy > Fixed option should be set to
0.01).
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This option is unavailable in the
Texture mapping mode.
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Display Options: Defines the
display options.
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Limited
color range: Makes a simplified analysis, with only three values
and four colors, display by default.
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Full color
range: Makes a complete analysis based on the chosen color range.
This allows you to see exactly how the evolution of the distance is
performed on the selected element, this functionality is P2-only.
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Displays the colored points: Displays the distance
analysis in the shape of points only on the geometry.
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Texture mapping mode: Checks the analysis using color
distribution:
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This option is only available with surface
elements in at least one set, providing this set is discretized.
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The distance is computed from this
discretized set to the other set.
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The texture mapping is computed on the
discretized surface. It is not advised to use it with planar surfaces
or ruled surfaces.
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A user
defined color without associated value is added in the full or the
limited color range, which allows you to manage an independent color
for no valuated area.
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Statistical distribution,
Min value Max value, and Points cannot be visualized when using
the Texture mapping mode.
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2D
Diagram: Displays a 2D diagram representing the distance
variation. This option is available only for mono-cell curve source
element.
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Display Statistics: Displays the percentage of points
between two values, effective when the
Color scale option is selected. This option is unavailable in the
Texture mapping mode.
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Min value: Displays the minimum distance values and
locations on the geometry.
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Max value: Displays the maximum distance values and
locations on the geometry.
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Enables running point: Allows you to display precise
distance value between the point below the pointer and the other set
of elements when you move the pointer over the discretized element.
The projection is visualized and the value is displayed in the
geometry area. Note that the analyzed point is not necessarily a
discretized point in this case. This is obvious when a low
discretization value is set.
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Comb Options
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Display the comb: Displays the distance analysis in the
shape of spikes on the geometry. Further, sets the ratio
for the spike size.
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zoom-independent length: Sets an automatic optimized
spike size.
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Inverts the spikes: Inverts the spike visualization on
the geometry.
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Envelope Display: Displays the envelope, that is the curve
connecting all spikes together.
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Select Surface.1.
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Select Running Point and move the pointer over
the discretized element.
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Select Color Scale option.
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The Distance.1 dialog box appears and
shows the Limited color range and identifies the maximum and
minimum values for the analysis. |
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The distance analysis is computed. Each color
identifies all discretization points located at a distance between two
values, as defined in the Limited color range dialog box. |
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Select Full color range
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The Distance.1 dialog box shows the
Full color range and identifies the maximum and minimum values
for the analysis. |
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The distance analysis is computed. Each color
identifies all discretization points located at a distance between two
values, as defined in the Full color range dialog box. |
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The following description is valid for the
Limited color range and the Full color range dialog boxes.
Whichever mode you choose the use of the color scale is identical: it lets
you define colors in relation to distance values. You can define each of
the values and color blocks, therefore attributing a color to all elements
which distance falls into to given values.
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Right-click a color rectangle in
the color scale to display the contextual menu:
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Edit
contextual command allows you to modify the values in the color range
to highlight specific areas of the selected surface. The Color
dialog box is displayed allowing you to modify the color range.
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Unfreeze contextual command
allows you to perform a linear interpolation between non-defined
colors.
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No Color contextual command can
be used to simplify the analysis, because it limits the number of
displayed colors in the color scale. In this case, the selected color
is hidden, and the section of the analysis on which that color was
applied takes on the neighboring color.
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You can also right-click on the value to
display the contextual menu:
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Edit contextual command allows you to modify the edition values.
The Value Edition dialog box is displayed: enter a new value
(negative values are allowed) to redefine the color scale, or use the
slider to position the distance value within the allowed range, and
click OK.
The value is then frozen, and displayed in a green rectangle.
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Unfreeze contextual command
allows you to perform a linear interpolation between non-defined
values, meaning that between two set (or frozen) colors/values, the
distribution is done progressively and evenly. This command is
available for all values except for maximum and minimum values.
The unfreezed values are no longer highlighted in green.
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Use
Max / Use Min contextual commands allow you to evenly
distribute the color/value interpolation between the current limit
values, on the top/bottom values respectively, rather than keeping it
within default values that may not correspond to the scale of the
geometry being analyzed. Therefore, these limit values are set at a
given time, and when the geometry is modified after setting them, these
limit values are not dynamically updated.
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These commands are available for maximum
and minimum values only.
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The Use Max command is
available if the maximum value is higher or equal to the medium
value, otherwise you need to unfreeze the medium value first.
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The Use Min command is
available if the minimum value is lower or equal to the medium value,
otherwise you need to unfreeze the medium value first.
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Use Min Max
button in the Distance Analysis.1 dialog box makes in one
action the Use Max / Use Min contextual commands
operation.
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The Distance Analysis.1 is created
in the specification tree under the Free Form Analysis.1
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The color scale settings (colors and values) are
saved when exiting the command, meaning the same values will be set next
time you edit a given distance analysis capability.
However, new settings are available with each new distance analysis. |
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Click Use Min Max button in the
Distance.1 dialog box.
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Maximum and minimum values are set according to
the computed values displayed below the color scale. |
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The color range has been redefined according to
the color scale. |
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Select Planar distance
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Distance is computed between Curve.1
and the intersection of the plane containing that curve |
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Select 3D
and the X option in
the Measurement Direction:
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Distance is computed along the X direction. |
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Select the Normal Direction option:
and the 2D
Diagram option:
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The 2D Diagram dialog box
appears and allows you to visualize the distance evolution. |
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The 2D Diagram dialog box
displays the following options:
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Inverse Y axis value :
Draws the curves in a linear horizontal
scale and and inverse vertical scale.
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Reframe
: Reframes
the diagram within the viewer window, as you may move and zoom it within
the window.
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Display a panel with
more options
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Displays the Diagram Options dialog box that enables you to
define more options.
- Grid
Customization: The
number of lines
displayed on grid during
zoom depends on the
following options:
- Automatic scale factor: Defines the space between two coordinate lines when when there are not enough lines in the viewer.
- Maximum lines number: Defines the maximum number of lines displayed in the viewer without zooming.
- Primary spacing on X: Defines the distance between the coordinates of the X-axis.
- Primary spacing on Y: Defines the distance between the coordinates of the Y-axis.
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- Display
Options: The
display in the 2D
Diagram can be
customized:
- 2D cursor: Select this option to display the 2D cursor.
- Caption: Select this option to display the caption area.
- Grid: Select this option to display the grid.
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- Zoom
Mode: There are
two ways to zoom in the
viewer window.
- using the mouse you can navigate in the viewer graph by panning (translation) and zooming in it.
- You can define a frame in the area where to zoom in. The graphical area is selected by using trap selection with the mouse. For zoom by trap two types of stretching are available:
- Standard: There is no stretching. The area is zoomed in the window and the X-axis and Y-axis intervals depend on the values defined in Primary spacing on X and Primary spacing on Y.
- Automatic: The horizontal X-axis interval corresponds to the interval resulting from zoom. The vertical Y-axis interval corresponds to the extrema computed from the Xmin and Xmax of the X-axis interval.
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The following values are displayed for all the analyzed curves in
2D Diagram dialog box:
- Xmin:
The minimum abscissa of all
the curves in the graphical
area.
- Xmax:
The maximum abscissa of all
the curves in the graphical
area.
- Ymin:
The minimum ordinate of all
the curves in the graphical
area.
- Ymax:
The maximum ordinate of all
the curves in the graphical
area.
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For more information on 2D Diagram dialog box,
see
Performing a Curvature Analysis.
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Whenever the 2D Diagram option is enabled
in Distance Analysis, you can open the 2D Diagram
dialog box. |
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Select the Limited color range option:
and select the
Statistical distribution option.
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Select the Display colored Points option and clear the
Display the comb option.
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Show the distance analysis in the shape of
points only on the geometry. |
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Select the Limits the descretized curve option.
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Two manipulators appear at both extremities of
the curve: they let you define new start and end points on the curve. |
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Start and end points are defined by a ratio of
curve length between 0 and 1. If you extend the curve for instance, this
ratio is kept. |
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Set the User Max Distance value to 220mm.
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The maximum value is re-limited accordingly on
the geometry. |
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Select the Source elements and remove the
Curve.1 from the selection, then select
Surface.17.
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Select the Texture mapping option, the
display the comb
option is automatically deselected.
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Select Full color range
and click the
Use Min Max button in the Distance.1 dialog box.
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The user defined color is displayed in the
Distance.1 dialog box. |
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The texture mapping is displayed on
Surface.17. |
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Define the color as magenta in the Distance.1
dialog box.
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The non-valuated area is magenta-colored. |
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Click OK to exit the analysis while retaining
it.
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The analysis (identified as Distance Analysis.x)
is added to the specification tree. |
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Even though you exit the analysis, the color
scale is retained till you explicitly close is. This is like a shortcut
allowing you to modify one of the analyzed elements, which leads to a
dynamic update of the distance analysis, while viewing the set
values/colors at all times and without having to edit the distance
analysis.
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When analyzing clouds of points, in normal
projection type, the distances are computed as the normal projection of
each point of the first cloud onto the triangle made by the three points
closest to that projection onto the second cloud.
As it is a projection, using the Invert Analysis button does not
necessarily gives symmetrical results.
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When you select the geometrical set as an
input in the specification tree, all the elements included in this
geometrical set are automatically selected too.
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The auto detection capability is available
from the Dashboard.
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You can calculate
the minimum distance between two curves along a direction using the
Knowledge Expert product.
For further information, refer to the Knowledge Expert's User's
Guide, Reference, Functions Package, Measures chapter.
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In the Knowledge Base
Starting from R21, the equivalents of the former "First Set" and "Second
Set’ boxes are names as the "Target" and "Source" boxes respectively |