Transfering Alias to I-DEAS for Master Series 6

Software Requirements

• I-DEAS Master Series 6

• ALIAS SurfaceStudio, Designer, Studio or AutoStudio 9.0

Creating a Wire File in Alias

Follow these steps to create an Alias wire file for export to
I-DEAS Master Series:

1

Select the object you want to export to make it active.

2

Select File>Export>Active As-.

3

Select Wire from the File Format menu under Basic Save Options.

4

Click Save and specify the wire file name. For export to Master Series 6, make sure that you add the .dat extension to the end of the file name.

The file is now ready to be read into I-DEAS Master Series.

Exportable Alias Geometry

The following geometry types can be exported to Master Series using I-DEAS Direct Connect:

• Single CVs (points)

• All curves (with or without attributes: lines, polylines, etc.)

• Faces

• Curves on Surface

• Surfaces

• Target Surfaces

• Trimmed Surfaces

• Trimmed Surfaces with multiple trim regions

• Target Trimmed Surfaces

• Shells

Polysets are the only geometry entities that are not supported by Master Series.

Integrating Studio Models in Master Series

Often the workflow will require that the designer send geometry over to the engineer using a CAD system. The CAD operator will then use the model to describe a solid part and perform other engineering process such as describing ribs, bosses and other mechanical details.

At any point the designer may need to update the information in the CAD system by re-exporting changes made to the original model in Studio so that those changes can be integrated into the CAD database.

Shelling Imported Geometry

For information on how to do shelling in Alias, see the NURBS Modeling in Alias book.

Shelling, or creating solid geometry from imported Alias models, is a common workflow in Alias and Master Series. When exporting a model from Alias, you must ensure that the geometry is built to the correct tolerance and that it can be stitched. The stitching process in Alias identifies gaps between surfaces so that you can repair the appropriate geometry before writing the file out to I-DEAS Master Series.

During stitching, the surfaces are twinned. This means that the surface boundaries may be split to accommodate adjacent surfaces, and periodic geometry is detached into multiple surfaces.

For this reason, you should save the Alias wire file before stitching so that if further modifications are required to be made to the Studio model, the construction history will be intact. (Stitched geometry saved to an Alias wire file cannot be unstitched to its original state.)

A typical workflow for shelling:

1

Stitch the surfaces and carry out a visual check to confirm there are no gaps.

2

Undo the stitch operation (Edit > Undo or Ctrl-Z).

3

Save the Alias wire file.

4

Stitch the surfaces again and export the stitched object to a wire file.

Exporting Features from Alias

The term part in I-DEAS Master Series refers to geometry that has been saved out as a part. The term feature refers to any attribute that augments the basic shape of a part and distinguishes it from other parts that could be derived from the same basic shape. More precisely, features are objects whose key dimensions and orientations have been controlled, thus allowing you to control your design. You can bring in parts or features to replace existing features on the workbench.

Since I-DEAS Master Series creates each element of a model as a part or feature, it is useful to import components of the Alias model as individual Alias wire files that can be manipulated in I-DEAS Master Series as individual features. Major components of the Alias model can be transferred separately so that they can be used to construct individual features. The advantage of this technique is that individual features can be "replaced" to give added flexibility.

Surface Replacement Technique

This technique can be very useful when the model is a mix of mechanical elements defined by an engineer and styling elements defined by an industrial designer.

To replace surfaces:

You must import the Alias model as an "Orphan Node". You can confirm that this is the case from the History Access window.

To open the History Access window:

1

Select the History Access menu item from the second section of the icon panel.

2

You are prompted to select the entity for which you want information. Select the model on the workbench, and in the Access window select the orphan node of the part.

Next, you will import the Alias wire file model which represents the changes that are required to be incorporated.

3

Select File > Import. From the File Import list, select Freeform Surfacing.

4

A popup window is displayed.

Select ALIAS. The File Name Input window appears.

Either:

• Type the fully qualified path name of the file you want to import in the Freeform Surfacing file name field.

• Select the directory mask button (labeled above) to use a file lister from which you can select the file you want to import:

5

Select OK.

The I-DEAS List window displays the import progress and the new model is imported on top of the original geometry.

6

Once the model has been imported, if necessary, position the stitched geometry where you want it in relation to the existing part in I-DEAS Master Series.

7

Ensure that the orphan node of the original model is still active, and then select Modify Entity.

8

A popup menu is displayed. Select Replace Feature.

You are prompted to select the geometry that will be used to replace the original feature.

9

Once you select the feature, you are prompted whether or not you want to control the associativity of mapping the old and new geometry.

If you select Yes, the screen splits into two areas. You are prompted to map the original geometry to the geometry of the newly imported model.

10

When the mapping has been completed, click the Update icon from the second section of the icon panel.

The original feature is replaced by the imported geometry and a new feature exists with all the nodes acting upon the new Orphan Node.

Summary

Use the following summarized list of modeling practices as a quick reference guide to avoid data transfer problems.

Before you create the model

• Units should be set to mm.

• In the Construction Options window:

• The Modeling Modes should be set to NURBS.

• Tolerances should be set to the following values

• Curve Fit Distance = 0.005 mm

• Maximum Gap Distance = 0.005 mm

• Curve Fit Checkpoints = 10

• Trim Curve Fit = 0.001 mm

While you create the model

See NURBS Modeling in Alias for a description of these tools.

• Use degree 5 curves and surfaces to achieve curvature continuity between surface geometry for successful data transfer.

Master Series I-DEAS does not support degree 7 geometry. Geometry created in Studio which is degree 7 will be rebuilt to degree 3 (cubic) upon import to I-DEAS. Adjacent Studio surfaces which had been built with continuity between them may no longer have that continuity after they are rebuilt in I-DEAS.

• Use surface building tools such as Square and Birail that allow you to impose curvature continuity between adjacent surfaces. Also, use the Rebuild option within these surfacing tools so that surfaces with interior multi-knots cannot be built.

• Surfaces should be overbuilt and trimmed back before export. This will result in a greater success rate when the surface geometry is offset in SDRC.

• Fillets and other detail geometry should be deleted from the Alias model before export. Ideally, surfaces that describe major form definition and design intent should be built in Studio, and fillets and detail geometry should be built in I-DEAS Master Series. Fillet and detail geometry created in Master Series give the SDRC user parametric control of that geometry while using I-DEAS Master Series.

• Models should be transferred periodically from Alias to Master Series during construction to manage the quality of the model being created.

• The Alias model must be successfully stitched before export, but you should also periodically stitch the geometry during model creation in Alias to ensure that the model meets all tolerance requirements.

• Avoid using Attach and Join Curve since these functions create multi-knots in Alias geometry that are not supported by Master Series.

• Avoid using Skin and Patch between trimmed surface boundaries since excessive amounts of data are created in the resulting surface.

• Use surface building tools such as Square and Birail, taking advantage of the Boundary Rebuild option to control curvature continuity between surfaces and ensure surfaces do not contain multi-knots.