Trim Convert

3D Trimming

If this box is checked, you can trim the surface along projected curves and cross sections, or you can select a surface and generate a trimming curve automatically from the intersection with the target surface. By default it is unchecked.

Method

Displays when 3D Trimming is selected.

• Project – Creates trimming curves by projecting the selected curves onto the target surface.

• Intersect – Creates a trimming curve from the intersection of the selected surface and the target surface.

You can use the Project or Intersect method in a single trimming operation by toggling back and forth between them.

Extend

Extend a curve that does not project entirely on the patch, either automatically or manually, and continue the trim operation without leaving the tool.

Auto

When the trim fails, any curves-on-surface that are within the set Tolerance of another curve-on-surface or boundary are extended and the trim is attempted again.

Selected

A trim extend arrow appears on the curve that needs extending. Clicking the arrow snaps the end of the curve to the patch edge.

Vector Options

These options are only available if 3D Trimming is turned on.

X, Y, Z

Specifies a projection vector along that axis.

View

Specifies a vector normal to the current view. The vector is not drawn in the view windows.

If the current view is changed, click Refresh View Vector to update the vector.

Picked

Lets you specify the name of an existing vector in the Picked Vector field, or pick the vector in the view.

Normal

The projection is done along the surface normals instead of using a single vector direction.

Picked Vector

This text field only appears when Picked is selected. It displays the name of the selected vector object. Alternatively, you can type in the name of a vector object.

Refresh Vector

This button only appears if View is selected. Click it to update the vector if the view has been modified

Retain Vector

Click this button to create a vector construction object in the view windows.Otherwise, the tool uses the vector direction you specified, but you are not able to see and re-use the vector.

Create Vector

Click this button to create a projection vector.

Click in the view to place the start point of the vector, or type the position and press . Use the vector manipulator to position the vector then click Accept.

Control Options

U Degree, V Degree

The degree of the new untrimmed surface in the U and V directions.

U Spans, V Spans

The number of spans of the new untrimmed surface in the U and V directions.

Switch U/V

Turn on this option to change the orientation of the U and V axes on the new trim converted surface.

Show Surface Deviation

Displays the maximum deviation between the original trimmed surface and the new untrimmed surface.

Show Edge Deviations

Displays the maximum deviation between each edge of the original trimmed surface and the new untrimmed surface.

Keep Originals

Keep the original trimmed surface after creating the new untrimmed surface.

Auto Update

Automatically updates the surface when you adjust the Trim Convert Settings.

Create Metadata

Specifies whether or not the Trim Convert tool creates history metadata.

Display Options

Show Intersections

If this box is checked, green locators indicate the intersections between the trim curves, and between the trim curves and trim surfaces. Red locators indicate trim curve endpoints that do not intersect any other curve-on-surface or trim surface edge.

Region Selector Length

Adjust the value if the selectors (crosses) appear too small or too large on your model. Displays trim locators based on pixel size rather than based on the size of the surfaces to be trimmed.

Note: The Shrink Surface option has been replaced by a plug-in called shrinkToTrim which can be loaded through Utilities Plug-in Manager. shrinkToTrim shrinks the UV parameters of the underlying surface to cover only the visible (non-trimmed) parts of the surface. This functionality is useful when applying label-style textures to the surface.

Trim convert a surface

Use this tool to trim a surface and converts the four-sided trimmed surface to an untrimmed surface with the same shape.

1. Select the Trim Convert tool.

2. Select a surface which has curves-on-surface defining closed regions. You can only trim convert one surface at a time.

   Note: If 3D Trimming is turned on, you can either select curves to project onto the surface, or cross sections, to define the trim regions. You can also select a vector option. If you are trimming a surface with its own cross-sections, choose Normal as the vector option.

3. Click on the regions to keep. Make sure that those regions define a four-sided surface.

   Crosshairs appear on the selected regions. (The size of those region selectors can be modified through the option window.)

   

4. Click the Convert button

   The tool trims the surface, then attempts to convert the trimmed surface to a new surface with natural boundaries.

   Note: If the trimmed surface is not four-sided, the system issues an error and asks you to redefine the trim region.

   If Show Surface Deviation is turned on, a locator shows the maximum deviation between the original and the converted surface.

   

5. If you are not happy with the result, click the Revert button to get back the original untrimmed surface.

Reshape a NURBS surface so its actual shape resembles its trimmed shape.

1. Select the Trim Convert tool.

2. Click a four-sided trimmed surface.

   Note: The Trim convert tool does its best job to match the shape of the trimmed surface with an untrimmed surface. In most cases, an exact match will be impossible.
   Tip: Turn on the Show Edge Deviations and Show Surface Deviations options to attach deviation locators to the resulting surface to see how much the new surface differs from the original.