|This section provides a detailed description of each view
generation mode (including the advantages and restrictions pertaining to
The view generation mode can be specified as a setting, through
Tools > Options > Mechanical Design > Drafting > Generation tab. In
this case, it will be used when creating new views. Refer to
Settings > View for more information.
Once the view has been created, you can modify its properties through
the Properties dialog box: from the contextual menu of a given
view, select Properties, click the View tab and then
select the desired options. For more information, refer to
Editing View Properties.
Exact views are generated from the Design mode: they are views for which
the geometry is available. The exact generation mode will be the best
option in most cases:
- This is the fastest generation mode.
- All types of views can be generated using this option.
- All functionalities (dress-up, dimensions, annotations, etc.) are
However, there are a few cases in which choosing the exact generation
mode will not be appropriate:
- In the case of sophisticated products or assemblies involving large
amounts of data, generating exact views may consume too much memory.
- Polyhedral elements (such as surfaces, wireframes, etc.) from V4 .model
documents are not supported.
- When generating exact views for assemblies containing clashing
bodies, some geometrical elements may not be generated.
From V5R17, in a section view or a
breakout view, a screw in a threaded hole is no more considered as a
clash, when the following conditions are respected:
- The screw must be designed as a whole CATPart document.
- A thread feature must be applied to the screw, and the hole
must be created as a threaded hole (refer to Creating
threaded holes in the Part Design User Guide).
- On the part instance associated to the screw, you must either:
- from the CATProduct document, select the Do not cut in section views option via Edit > Properties > Drafting
- or from the CATDrawing document, clear the Cut in section views option via the Overloading
- The edges of faces with a relative angle of less than 0.5 degrees
are considered as being "smooth edges", and therefore are not
- For elements that are in contact but are not linked by
topological links, the exact view is computed with numerical
calculus. This can interfere the computation of hidden and shown
parts of edges and linear elements. When this can be done, apply a
boolean operation to by-pass this problem.
Raster views are generated as images. This enables you to quickly
generate overall views for large products or assemblies, regardless of
drawing quality. Such views are associative to the 3D geometry and can be
updated when the part or product changes.
Raster views involve a number of restrictions:
- You cannot generate the following types of views using this option:
view from 3D, section views, section cuts, detail views, breakout views,
- Raster views cannot contain dress-up elements (axis, center lines,
- Creating dimensions is impossible.
- Generally speaking, all commands requiring the selection of geometry
are not available.
- Raster views cannot be edited (you can work around this by isolating
the view: double-clicking the image will then launch an image editor).
As a consequence of these restrictions, selecting this option disables a
number of other options on the View and on the Generation
tab (available through Tools > Options > Mechanical Design > Drafting)
or in the Properties dialog box (available through Edit >
CGR views are generated using the CGR format (CATIA Graphical
Representation). A CGR format only contains a graphical representation of
the geometry, which is available with the Visualization mode (as opposed to
the exact geometry, which is available with the Design mode). The CGR view
uses and displays only the external appearance of the component; the
geometry is not available. The corresponding .cgr file, if it exists, is
inserted from the cache system.
To generate a correct CGR view from an assembly composed of .cgr files,
use only high quality .cgr files, containing data about edges and faces.
For example, a .cgr file created with DMU Optimizer miss this information
(to be as light as possible). In this particular case, the CGR view mode
can produce unpredictable results.
CGR views are not as high in quality as exact views, but they consume
much less memory during the generation. This may be useful when dealing
with sophisticated products or assemblies involving large amounts of data.
However, this generation mode is rather slow.
For more information about the advantages and restrictions associated
with the CGR generation mode, see
Advantages and restrictions common to CGR and Approximate modes below.
Approximate views are generated using the Approximate mode. Although
Approximate views are not as high in precision and quality as exact views,
this generation mode dramatically reduces memory consumption. Performances
may also be improved, depending on how you fine-tune precision. Therefore,
the Approximate mode is particularly well-adapted to sophisticated products
or assemblies involving large amounts of data.
The Approximate mode offers about the same advantages and restrictions
than the CGR generation mode (see above). However, there are some
- Approximate consumes even less memory than CGR.
- Approximate is faster than CGR, but performances largely depend on
- Approximate provides more approximate results than CGR, but these
results largely depend on how you fine-tune precision.
- Approximate lets you generate section views, section cuts and
breakout views. However, note that certain restrictions apply, which are
documented in other parts of this user's guide, when appropriate.
For more information about the advantages and restrictions associated
with the Approximate generation mode, see
Advantages and restrictions common to CGR and Approximate modes just
Using CGR or Approximate to generate views offers the following
- Optimize memory consumption when generating and handling projection
views for large products or assemblies.
- Generate views from third-party data (such as MultiCAD), as well as
from polyhedral elements (such as wireframes, surfaces, etc.) in V4 .model
Be careful to use only high quality .cgr files, containing data about
edges and faces. For example, a .cgr file created with DMU Optimizer miss
this information (to be as light as possible). In this particular case,
the CGR and Approximate view modes can produce unpredictable results.
However, the CGR or Approximate generation mode involves a number of
- You cannot generate the following types of views:
- For CGR: section views, section cuts, detail views, detail view
profile, breakout views, unfolded views and views from 3D.
- For Approximate: detail views, detail view profile, unfolded views
and views from 3D.
- The following types of elements are not associative on CGR or
- For CGR: Auxiliary view profiles, annotations, dimensions, etc.
- For Approximate: Auxiliary view profiles, annotations, etc.
Dimensions may now be associative, depending on whether you select the
Allow the creation of associative dimension in approximate views
option in the Dimensions associativity on 3D dialog box (see
- You cannot project 3D elements such as wireframe, points, etc. on CGR
or Approximate views.
- CGR or Approximate views cannot contain dress-up elements (axis,
center lines, threads).
- Persistency of graphical properties edition (color, line type, line
thickness, no show) and Delete operations performed on generated elements
are not available on CGR or Approximate views.
- CGR or Approximate views being only a graphical representation of the
geometry, only line segments are generated in such views. In the case of
non-associative dimensions (as is always the case for CGR views, and may
be the case for Approximate views when the Allow the creation of
associative dimension in approximate views option is not selected),
the only elements that can be dimensioned are these line segments.
As a result, you may not be able create certain types of radius or
diameter dimensions in such views.
- Approximated items cannot be selected using trap selection. However
you can click on
to select and edit single item properties. Note that you can also
multi-select several items using the Ctrl key.
- Approximated items cannot be duplicated. The Duplicate
command is not available using contextual menu on an approximated item.
- The mesh thickness has an impact on the CGR and approximate view
performance. Moreover, a CGR view cannot be computed from an extremely
thin mesh, i.e. when the mesh on a single face consists of more than
6500 triangles. In this special case, you must raise the 3D accuracy
(using Tools > Options > General > Display > Performance tab
> 3D Accuracy options) before projecting a CGR view.
As a consequence of these restrictions, selecting either the CGR
or the Approximate option disables a number of other options on
the View and on the Generation tab (available through
Tools > Options > Mechanical Design > Drafting) or in the
Properties dialog box (available through Edit > Properties).