Simplifying Surfaces

This task shows how to simplify the topology of adjacent surfaces under given thresholds to make a simple surface of one element.

Open the SurfaceSimplification_1.CATPart document.

1. Click Surface Simplification in the Operations toolbar.

   The Surface Simplification dialog box appears.

2. In the Surface box, select the surface to be simplified.

   You can select several faces by clicking .

   
   

3. In the Faces to Merge box, select the faces to be merged from the surface to be simplified.

4. In the Faces selection assistant area:
   You can select the micro faces as the faces to be merged by defining certain ratio.

   a.	In the Ratio box, type the value or use the arrows to enter the ratio of the area of any individual face you want to merge with respect to the area of the complete selected surface.
   	By default, the ratio is set to 1.
   b.	Click Micro faces to select the faces to be merged.
   	Micro faces have the area less than or equal to the ratio defined.
   c.	Click Select to retrieve these micro faces.
   	The retrieved micro faces are selected as faces to be merged and the Faces to merge box is automatically updated.
   d.	To cancel the selection, click Clear.

   or
   
   You can select the thin faces as the faces to be merged by defining the offset value.
    

   a.	In the Offset box, define the value by which the boundary of an individual face can offset inwards.
   	By default, the offset value is set to 1mm.
   	If a face is created by offsetting the boundaries of an existing face inwards, with offset value more than or equal to the value defined in the offset box. If this new face does not have any matter, it is defined as a thin face.
   b.	Click Thin faces to select all such faces to be merged.
   c.	Click Select to retrieve these thin faces.
   	The retrieved thin faces are selected as faces to be merged and the Faces to merge box is automatically updated.
   d.	To cancel the selection, click Clear.

    

5. Click Preview.
   In the Preview information area, you can visualize the deviation information. The same information is visible in the 3D geometry area when you pause over the Maximum Deviations balloon.

6. In the Maximum deviations area, you can type the value or use the arrows to change values in the following boxes:

   Maximum inner distance deviation: allows you to define the maximum possible inner distance deviation the resulting surface can have as compared to the input surface. By default, it is set to 0.15mm. Maximum boundary distance deviation: allows you to define the maximum possible boundary deviation the resulting surface can have as compared to the input surface. By default, it is set to 0.001mm. Maximum boundary tangency deviation: allows you to define the maximum boundary tangency deviation the resulting surface can have as compared to the input surface. By default, the check box is selected and the value is set to 0.5deg. You can visualize each type of deviation by selecting it from the Deviation Analysis list. The points that exceed the maximum deviation are highlited in the 3D geometry area. Each point is color-coded and corresponds to the percentage of error from the maximum allowed deviation value:

7. Optionally, you can visualize each type of deviation by selecting it from the Deviation Analysis list. The points that exceed the maximum deviation are highlighted in the 3D geometry area. 

   Each point is color-coded and corresponds to the percentage of error from the maximum allowed deviation value:

   0 % means that the deviation value is the maximum allowed value. 100 % means that the deviation value is 2 times the maximum allowed value. 200 % means that the deviation value is 3 times the maximum allowed value, and so on.

8. Click OK.
   The surface (identified as Surface Simplification.xxx) is added in the specification tree.

   While editing the simplified surface, the values defined in the Ratio and Offset boxes for Micro faces and Thin faces respectively are set to default.