Alias CATIA V5 DirectConnect
is a stand-alone utility that allows the exchange of 3D model data
between Alias and CATIA V5 using the native CATIA part (.CATPart)
and product (.CATProduct) files.
CATIA Requirements
- CATIA V5 (Release 6 - 18).
- Version 2011 of an Alias software
product.
- Windows operating system.
See Before you create the model for
a list of modeling practices to use as a quick reference guide if
problems arise.
Before you create the model
- Set optimal
tolerances in accordance with CATIA V5. The default tolerances are:
- Curve Fit Distance =
0.001 mm
- Curve Fit Checkpoints =
10
- Max Gap Distance =
0.001 mm
- Trim Curve Fit =
0.005 mm
- Topology Distance =
0.02 mm
(CATIA tolerances are
set for large scale objects as well as for normal scale objects.)
While you create the model
- Periodically transfer models from Alias to
CATIA during construction to manage the quality of the model being
created.
- The Alias model should be capable
of being successfully stitched before export. If you periodically
stitch the geometry to ensure that the model meets all tolerance
requirements, you’ll have a good indication of whether the final
model will stitch correctly.
- Avoid using Object Edit > Attach > Attach since this function creates
multiknots in Alias geometry that may result in unusable geometry
in CATIA.
- Use surface building tools such as Square
and Rail Surface, taking advantage of the Boundary Rebuild option
to control curvature continuity between surfaces and ensure that
surfaces do not contain multi-knots.
- Use Evaluate > Check Model to be alerted to potential
problems: it’s another good practice.
Workflow
Before transferring geometry
between Alias and CATIA, consider the purpose of the transfer
to plan an appropriate workflow. Two common workflows are:
- Geometry (describing mechanical components)
is transferred from CATIA to Alias for concept design surfacing,
then those Alias surfaces are transferred back to CATIA.
- A Alias model is transferred to
CATIA, and both Alias and CATIA databases are developed independently.
Later, the modified Alias model is transferred again to CATIA,
replacing the Alias geometry from the first transfer. In this
scenario, all work done in CATIA on the first Alias model transfer
will affect the new, modified geometry.
There are many variations
on these two examples. Whatever the transfer scenario, carefully
plan the transfer process, to ensure that the appropriate data is
written out and is useful.
What are the curve fit
distance tolerances in Alias
The Curve
Fit Distance is the tolerance to which trim boundaries
are rebuilt to (or approximated). The default positional tolerance
in CATIA V5 is 0.001 mm, and the Alias Curve
Fit Distance setting should be set to 0.001 mm.
This Curve
Fit Distance setting should normally be accurate. If
you find that it is not resulting in Alias geometry that can
be successfully used in CATIA, then experiment with the Curve
Fit Distance—it can set to as low as 0.001 mm. This setting
will enhance the success of post transfer processes, such as skinning,
that are to be carried out once the geometry is in CATIA.
TipDo
not set the Curve Fit Distance tolerance
in Alias at less than 0.001 mm. Lower than this will affect
processing time.
Whether you are creating
a model, verifying a model, or debugging a translation, there are
a number of tools in Alias you can use to check the quality
of the geometry you have created. The most useful tool is the Locators
> Deviation Min/max measurement tools. Use this tool
to check the maximum distance between any two surface boundaries.