• Tool >> Decimate >> High Quality command reduces the number of faces of multiple shells or a selected region.

• This command merges vertices and relocates them to new positions to reduce the number of faces while preserving the original shape. By using this command, a shell or even a portion of a shell can be represented with the optimal number of faces.

• Tool >> Decimate >> High Quality command can be applied to both the selected shell and region.
   

Step   

Execute Tool >> Decimate >> High Quality command as follows:

1. When there is no selected region, this command applies to the selected shell. When there is a selected region, this command applies only to the selected region.

2. Select Tool >> Decimate >> High Quality from the menu or click the corresponding icon from the polygon Tool1 toolbar.

3. In the case of decimating a shell, select the desired shells by mouse drag. ( See Selecting Shell )

4. The following dialog box should appear.

When the dialog box appears, the number of current faces is shown initially in Number of faces field.

In the Number of faces or Reduction Ratio field, type in the number of faces to retain or the percentage of the numbers of remaining faces to that of the original faces, respectively. In case of multiple shells, the Number of faces or Reduction Ratio is shared to all shells by same distribution ratio.

With Curvature Balance slide, User can adjust reduction ratio of curvature and planar area. More rigorous calculation will be executed in order to make the faces of the decimated shells as uniform as possible. The more the slide goes to left, more planar area will be reduced.

In the Error Bound filed, specify the error bound which indicates the allowable amount of vertex displacement from the original model during decimation. This value is interpreted in the unit specified by External Data Unit in General tab of Preferences dialog box. ( See File >> Preferences )

Check Don't move original vertices option to retain the positions of remaining vertices.

Check Don't modify boundary edges option to retain the boundary shape.

Check Try to preserve mesh quality option to perform more rigorous calculation for making the modified faces as uniform as possible.

The Preserve Marked Edges / Vertices option determines whether or not to preserve the marked edges or vertices.

To preserve color information, you should check Preserve Color. If Preserve Vertex Color is checked, the vertex color will be preserved. Color Balance is used to adjust how much the color will be preserved. It has three stages. The more the slide is at the right, the boundaries between different colors will be better preserved. If Create Texture Image is checked, you should specify Texture Image Size whose range is: 64-2048. And then a texture of that size will be created.

5. Press OK button to complete this command.

• As for Tool >> Decimate >> High Quality, it might take much time to decimate the region where there are extremely many polygons.
• Checking Try to preserve mesh quality option may increase calculation time much more. Thus, use the option if it is really necessary.

• This command is texture preserve command. So if user don't have Color workbench license, Rapidform shows a below message.

If user select OK, texture will be removed after execution, If Cancel, execution will be canceled.

• If this command is applied to a shell, depending on its type, you can use different option:
  If it is vertex color shell, you can select either Preserve Vertex Color or Create Texture Image.
  If it is face color shell, you can select only Create Texture Image.
  If it is shell with UV texture for vertex, only the Create Texture Image option is checked.
  If it is shell with UV texture for face, only the Create Texture Image option is checked.

• If this command is applied to selected region, depending on the shell type, you can use different option:
  If it is vertex color shell, Preserve Vertex Color is automatically checked.
  If it is shell with texture, Create Texture Image is automatically checked.
   

• If user does this process on polygon shell with feature region. Below warning message will appear.