The Advanced GSM Command User Interface

Once you have started the Advanced GSM command there several areas to be considered:

7 Additional Options

6
Setting Associativity

1 What to Modify

2 What to Preserve and How

3 What to Match and How

4 Which entities the shape must be Through and How

5 Which target shape has to be matched

1 — What to Modify

The Entities drop-down list enables you to select the type of entities to be modified (Solid, Surfaces, Curves, Points). Once you have selected the type (default is Solid) you can select the entities to be modified in the model.

2 — What to Preserve and How

Preserving conditions define what has to be preserved in the modification and how. They can be applied to points, curves, surface contours and hghlight lines (What) and they cover conditions like position, tangency, curvature etc. (How).

3 — What to match and How

Matching conditions define the modification in terms what is the initial shape and the target one, and how they behave. As above, they can be applied to points, curves, surface contours (What) and they cover conditions like position, tangency, curvature etc (How)

For example, in the following illustration:

What to Modify: the surface
What to Preserve the green boundary, How: keeping position
What to Match: the blue curve with the red one, How: target position
Please note that the selection list is dynamically updated while you select entities in the model. Sometimes it can be longer than the graphics area; scrolling arrows are provided to enable you to reach the desired items: , .If you hold down the SHIFT key when clicking the arrows, you will scroll five items at a time instead of just one.

Suggestion about selection
In some situations, to make selection easier, it can be useful to select the entities to be modified after the entities to match and/or to preserve. This way, selection is much quicker, as nothing is highlighted in the model. On the contrary, especially in complex models, if you first select the entities to be modified, recognizing and selecting the entities to match and/or to preserve among a number of highlighted entities might not be as easy.

Read the Introductory examples on GSM to learn more.

4 — Which entities the shape must be Through and How

A most useful set of powerful constraints is available under the Passing Through node. They enable you to apply a controlled modification to a shape so as to make it pass through some specified points, curves and surface boundaries or even highlight lines (What). Conditions covered are position, tangency, curvature etc. (How). See "Modifying a shape so as to constrain it to be through some other entities" for details.

5 — Which target shape has to be matched

You are enabled you to specify shape constraints on curves and points. To apply these constraints, you can select Curves or Points in the Target Shape drop-down list under the Target Shape node.

Using these options you can apply a controlled modification to a shape (using its boundary curves or points) so as to match target shape conditions that can be a line, plane, sphere, cylinder etc. See the "Shape Constraints" document for details.

6 — Setting Associativity

The Associative Mode check box affects solids and surfaces.
When the command is applied to surfaces:

If the Associtive Mode check box is selected, the result you will obtain is a solid, which will retain an associativity link to its base entities, so that if you modify such entities the solid will be updated accordingly.
If the Associative Mode check box is not selected, the result you will obtain is a set of curves/surfaces of the "GSM" type which describe the new shape. A set of special options is provided to convert such curves/surfaces into NURBS curves/surfaces, in the case you need to export them to some environment different from think3.
When the command is applied to solids:

If the Associative Mode check box is not selected, you can modify only static solids. If you select the Copy check box under More Options, a static copy of the original solid will be created and the changes will be applied to the copy.
If the Associative Mode box is selected, any type of solid can be modified.

7 — Additional Options

The additional area is displayed when you click More Options

It enables you to:

Copy Apply the changes to a copy of the original entities rather than to the original entities themselves

Hide Hide or display the original unmodified surfaces (default is they are hidden)

Quality Checks Perform quality checks on results

Approximation Obtain NURBS surfaces instead of specialized ones

Precision Set the precision values to be achieved

Shape Control Set the parameters controlling the shape of the resulting surfaces

Symmetry When checked — to select up to three symmetry planes about which the constraints you set will be mirrored for the model you are modifying. When not selected, constraints will not be mirrored.


7		Additional Options
6		Setting Associativity
1		What to Modify
2		What to Preserve and How
3		What to Match and How
4		Which entities the shape must be Through and How
5		Which target shape has to be matched

Copy	Apply the changes to a copy of the original entities rather than to the original entities themselves
Hide	Hide or display the original unmodified surfaces (default is they are hidden)
Quality Checks	Perform quality checks on results
Approximation	Obtain NURBS surfaces instead of specialized ones
Precision	Set the precision values to be achieved
Shape Control	Set the parameters controlling the shape of the resulting surfaces
Symmetry	When checked — to select up to three symmetry planes about which the constraints you set will be mirrored for the model you are modifying. When not selected, constraints will not be mirrored.