More about the Spatial Split Option

• Accessing the Spatial Split Option
• Benefits of this Option
• Spatial Split Option Impact on the Final Result

Accessing the Spatial Split option
 

To access the Spatial split option:

1. Click Swept Volume .
   The Swept Volume dialog box is displayed.

2. Select the Spatial Split check box. A new algorithm is used with the defined accuracy for the wrapping computation.

To take advantage of the new spatial split option:

1. Select Apply Wrapping check box.

2. Specify the appropriate Grain value (you can increase the grain value as the quality will remain satisfactory).

3. Select the Spatial Split check box.

4. Launch the swept volume calculation

   Notes: Using Wrapping and Simplification in Swept Volume provides a scenario example. When the spatial split check box is selected, the offset ratio option is disabled.

Benefits of this Option

Spatial split option is useful when dealing with a track presenting numerous positions or dealing with a large digital mockup.

The new spatial split algorithm computes a perfectly rounding envelope of a moving part.
This is referred as a convex envelope computation for the swept volume. Here is an example with comparative graphics: 

with the previous wrapping  algorithm (Grain value = 20)	with the new spatial split (Grain value = 20)

Spatial Split Option impact on the Final Result

Below, is a simple example of a convex envelope computation.
A convex envelope computation guarantees that the resulting shape is perfectly stretched around the initial model and released to conform as closely as possible to the initial model (i.e. intuitively, the convex envelope can be defined by imagining a wrapping elastic band stretched around the initial model).

With the spatial split option selected, the convex envelope of the initial model is computed for each voxel unit (defined by the grain size)

Once all necessary convex envelopes are computed, they are merged together and only the external envelope is kept in the final result. The computation time is increased but the new spatial split algorithm provides an absolute wrapping envelope (i.e. a convex shape tightly stretched open to encompass the initial model (see below in green)

Notes: Spatial split option improves the quality of the result envelopes but the computation time is increased. Specify a greater grain value to improve the calculation time thus without decreasing the quality level of the swept volume result. Spatial split calculation produces temporary files stored in the CATTemp directory. Before launching the swept volume calculation: Make sure that there is sufficient space on the drive where the CATTemp directory is stored. Do not compute more than two swept volume at a time in CATIA sessions using the same CATTemp directory. Otherwise computation errors and invalid behavior could occur. Due to mathematical computations and floating point round-offs, the difference between the initial model and the result envelope can vary up to a 1/20,000th of the bounding box size.