Surface Edit > Rebuild Surface

Recreates a surface with the same shape but different mathematical properties (for the purpose of simplifying it, or making it non-rational for export to a CAD package, for example).

Rebuild Surface Options

Rebuild Type: Rebuild – Change the degree (from 1 to 9) and the number of spans of the surface (along U or V independently) while maintaining the original distribution of spans and parameterization.

Non-rational – Rebuild a rational surface as a non-rational surface (all CVs with equal weights).

Reduce spans – Simplify the surface by removing extraneous edit points.

Del multi-knots – Remove multi-knots from the surface.

Uniform rebuild – Convert the surface to uniform parameterization.

Match knots – Convert the surface to match the parameterization and degree of another surface.

Rebuild options

These options appear when Rebuild Type is Rebuild.

Rebuild Direction: U and V – Rebuild the surface in both directions.

V Only – Rebuild the surface in the V direction only. (Edges in the U direction are not affected.)

U Only – Rebuild the surface in the U direction only (Edges in the V direction are not affected.)
Change Number of CVs: On – Change the number of CVs (and hence of spans) in the rebuilt surface. Either a slider or two number fields appear(s) allowing you to set the number of spans in the U and/or V direction(s).

Off – The number of CVs in the rebuilt surface is equal to the number of CVs in the original.
Change Surf. Degree: On – Change the degree of the surface as it is rebuilt. Either a slider or two number fields appear(s) allowing you to set the degree of the rebuilt surface in the U and/or V direction(s).

Off – Do not change the surface degree.

Non-rational options

This setting appears when Rebuild Type is Non-rational.

Tolerance: The maximum amount of deviation from the original surface permitted during the rebuild (in current linear units).

A low number matches the original more exactly, but does not simplify the surface as much. A high number does not match the original as well, but simplifies more.
Continuity Angle: The maximum angle allowed between the normals of the original and rebuilt surfaces. A smaller value matches the original more exactly, but usually requires the tool to add more spans to the surface.

Reduce spans options

This setting appears when Rebuild Type is Reduce spans.

Tolerance: The amount of deviation from the original surface permitted during the rebuild (in current linear units).

A low number matches the original more exactly, but does not simplify the surface as much. A high number does not match the original as well, but simplifies more.
Rebuild Direction: U and V – Rebuild the surface in both directions.

V Only – Rebuild the surface in the V direction only. (Edges in the U direction are not affected.)

U Only – Rebuild the surface in the U direction only (Edges in the V direction are not affected.)

Del multi-knots options

This setting appears when Rebuild Type is Del multi-knots.

Rebuild Direction: U and V – Rebuild the surface in both directions.

V Only – Rebuild the surface in the V direction only. (Edges in the U direction are not affected.)

U Only – Rebuild the surface in the U direction only (Edges in the V direction are not affected.)

Uniform rebuild options

These settings appear when Rebuild Type is Uniform rebuild.

Rebuild Direction: U and V – Rebuild the surface in both directions.

V Only – Rebuild the surface in the V direction only. (Edges in the U direction are not affected.)

U Only – Rebuild the surface in the U direction only (Edges in the V direction are not affected.)
Change Number of CVs: On – Change the number of CVs (and hence of spans) in the rebuilt surface. Either a slider or two number fields appear(s) allowing you to set the number of spans in the U and/or V direction(s).

Off – The number of CVs in the rebuilt surface is equal to the number of CVs in the original.
Change Surf. Degree: On – Change the degree of the surface as it is rebuilt. Either a slider or two number fields appear(s) allowing you to set the degree of the rebuilt surface in the U and/or V direction(s).

Off – Do not change the surface degree.

Control Options

Keep Originals: Keep the original curve after creating the rebuilt curve.
Auto Recalc.: Automatically update the new curve when the values in the Rebuild Curve window change.
MixMax Display: Automatically create and display min, mean and max locators between the original and rebuilt surfaces.
Max Deviation: Show the maximum deviation between the original and rebuilt surfaces on the prompt line, as well as the (U,V) location where it occurs.

Buttons

Recalc: When Auto Recalc. is turned off, use this button to update the rebuilt curve with the current values.
Undo All: Undo all the changes made by the Rebuild curve tool and return to the original curve.
Next: Finish rebuilding the current curve and prompt for a new curve to rebuild.