
This task shows how to analyze the distance
between any two geometric elements, or between two sets of elements. 

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. 

This command is only available
with:



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.

The element which 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 element, the system compares the greatest
dimension of all elements in each set, and discretizes the one with the
smallest dimension.


Open the
FreeStyle_Part_11.CATPart document. 


Select Curve.1.



Click the Distance Analysis icon:


The Distance dialog box appears, the
Second set state is selected: 



The Distance dialog box displays the
following options:

Selection State: defines the
elements to be analyzed. To add or remove an element in a set, use the
Ctrl key.

First set: defines the first set
of elements to be analyzed.
All the elements selected before running the command are considered in
the First set, the Second set is then
automatically selected.

Second set: defines the second
set of elements to be analyzed.

Running point: allows you when
you move the pointer over the discretized element to display more
precise distance value between the point below the pointer and the
other set of elements.
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, as shown here.

Invert Analysis: inverts the
computation direction. In some cases, when inverting the computation
direction does not make sense, when one of the elements is a plane for
example, the Invert Analysis button is grayed.

Projection Space: defines the
preprocessing of the input elements used for the computation.

3D: elements are not modified and the computation is done
between the initial elements.

X: projection
according to the X axis, the computation is done between the projection
of selected elements. Only available when analyzing distances between
curves.

Y: projection
according to the Y axis, the computation is done between the projection
of selected elements. Only available when analyzing distances between
curves.

Z: projection
according to the Z axis, the computation is done between the projection
of selected elements. Only available when analyzing distances between
curves.

Compass:
projection according to the compass current orientation, the
computation is done between the projection of selected elements.

Planar
distance: the distance is computed between a curve and the
intersection of the plane containing that curve. Only available when
analyzing distances between a curve and a plane.

Measurement Direction: provides
options to define how set the direction used for the distance
computation.

Normal
distance : the distance is computed according to the normal to
the other set of elements.

X: the
distance is computed according to the X axis.

Y: the
distance is computed according to the Y axis.

Z: the
distance is computed according to the Z axis

Compass:
the distance is computed according to the compass orientation.

Display Options: defines the
display options.

2D
Diagram: displays a 2D diagram representing the distance
variation

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 P2only.

Limited
color range: makes a simplified analysis, with only three values
and four colors, display by default.



Click the More button in the Distance
dialog box.




The Distance dialog box displays the
following extended options:

Color scale: to display the
Distance.x dialog box whether the full or the limited color range.

Statistical distribution: displays
the percentage of points between two values, effective when the
Color scale option is selected.

Min/Max values: displays the
minimum and maximum distance values and locations on the geometry.

Points: displays the distance
analysis in the shape of points only on the geometry.

Spikes: displays the distance
analysis in the shape of spikes on the geometry.
You can further choose to:

sets the ratio
for the spike size, available only when the Auto scale
option is unselected.

Auto scale: sets an automatic
optimized spike size.

Inverted: inverts the spike
visualization on the geometry

Envelope: displays the envelope,
that is the curve connecting all spikes together

Texture: checks the analysis using
color distribution:

This option is only available with surface
elements in at least one set, providing this set is discretized.

The distance is computed from this
discretized set to the other set.

The texture mapping is computed on the
discretized surface. It is not advised to use it with planar surfaces
or ruled surfaces.

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.

Statistical distribution,
Min/Max values, and Points cannot be visualized when
using the Texture option.

The discretization option should be set to a
maximum (in Infrastructure User's Guide, see Improving
Performances, the 3D Accuracy > Fixed option should be set to
0.01).

Run the View > Render Style > Customize
View command, and select in the Custom View Modes dialog
box which appears the following options to be able to see the analysis
results on the selected element. Otherwise a warning is issued:

Curve Limits: relimits the
discretized curve, this functionality is P2only.

Max Distance: relimits the maximal
distance value.

Discretization: reduces or
increases the number of points of discretization from the set of
elements which are taken into account when computing the distance.

Automatic trap: 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. When using the Automatic trap
option, a mean plane representing the delimited set of points of
discretization is computed from their distribution. If this
distribution is too scattered, this option may not be able to take
into account as many points as needed for a consistent result such
as an incomplete result or no result. In this case, it is best to
unselect the option.



Select Surface.1.



Select Running Point and move the pointer over
the discretized element.





Select the Color Scale option.


The Distance.1 dialog box appears and
shows the Limited color range and identifies the maximum and
minimum values for the analysis. 



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. 




Select the Full color range option:


The Distance.1 dialog box shows the
Full color range and identifies the maximum and minimum values
for the analysis. 



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. 



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.

You can rightclick on a color rectangle in
the color scale to display the contextual menu:

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 the user to modify the color range.

Unfreeze contextual command
allows you to perform a linear interpolation between non defined
colors.

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.

You can also rightclick on the value to
display the contextual menu:

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.

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.

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.

These commands are available for maximum
and minimum values only.

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.

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.

Use Min Max
button in the Distance Analysis.1 dialog box makes in one
action the Use Max / Use Min contextual commands
operation.

The Distance Analysis.1 is created
in the specification tree under the Free Form Analysis.1


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. 


Click the Use Min Max button in the
Distance.1 dialog box.


Maximum and minimum values are set according to
the computed values displayed below the color scale. 



The color range has been redefined according to
the color scale. 




Select the Planar distance option:


Distance is computed between Curve.1
and the intersection of the plane containing that curve 




Select the 3D option:
and the X option in
the Measurement Direction:


Distance is computed along the X direction. 




Select the Normal Direction option:
and the 2D
Diagram option:


The Distance Analysis.1 dialog box
appears and allows you to visualize the distance evolution. 



The Distance Analysis.1 dialog box
displays the following options:



Select the Limited color range option:
and select the
Statistical distribution option.





Select the Points option and unselect the
Spikes option.


Show the distance analysis in the shape of
points only on the geometry. 




Select the Curve Limits option.


Two manipulators appear at both extremities of
the curve: they let you define new start and end points on the curve. 



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. 




Set the Max Distance value to 220mm.


The maximum value is relimited accordingly on
the geometry. 




Select the First set state and unselect the
Curve.1 using the Ctrl key, then select
Surface.17.



Select the Texture option, the Spikes
option is automatically deselected.



Select the Full color range option:
and click the
Use Min Max button in the Distance.1 dialog box.


The user defined color is displayed in the
Distance.1 dialog box. 



The texture mapping is displayed on
Surface.17. 




Define the user color as magenta in the Distance.1
dialog box.




The non valuated area is magentacolored. 




Click OK to exit the analysis while retaining
it.


The analysis (identified as Distance Analysis.x)
is added to the specification tree. 


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.

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.

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.



The auto detection capability is available
from the Dashboard.

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.
