Surface Workbench¶

In one sentence: The Surface workbench creates smooth, continuous surfaces by filling boundary curves — essential for Class-A surfacing, complex organic shapes, and surface modelling that goes beyond what Part Design's solid-only workflow can achieve.

What is the Surface workbench for?¶

The Surface workbench creates NURBS surfaces from curves and edges. It bridges the gap between sketch-based parametric modelling (Part Design) and the curve-driven surface modelling used in automotive, consumer product, and industrial design.

Common uses:

Filling the open face of a solid body with a smooth curved patch.
Creating transitions between two surfaces with controlled continuity (tangent-smooth or curvature-smooth joins).
Generating a surface from a set of cross-section curves (lofting).
Extending a surface beyond its current boundaries.
Projecting curves onto a mesh for reverse engineering.

Key concepts¶

NURBS surfaces¶

All Surface workbench tools produce NURBS (Non-Uniform Rational B-Spline) surfaces. A NURBS surface is defined by a control point grid and associated weights — it can represent any smooth curved shape exactly or to arbitrary precision.

NURBS surfaces are fully compatible with Part and Part Design — you can combine them with solids using boolean operations and Part features.

Continuity types¶

When two surfaces meet at a shared boundary, there are several levels of geometric continuity:

Continuity	Symbol	Meaning
Position	G0 / C0	Surfaces touch — no gap, but may have a crease
Tangent	G1 / C1	Surfaces are tangent — no crease, but curvature may jump
Curvature	G2 / C2	Curvature matches across the boundary — smooth highlight lines
Acceleration	G3 / C3	Rate of change of curvature matches — needed for automotive

G0 is sufficient for watertight geometry.
G1 is required for visually smooth shading.
G2 is required for Class-A surfacing (automotive, consumer products) where highlight reflections must flow smoothly across panel joins.

Workbench layout¶

The Surface workbench has one menu (Surface) with six tools:

Tool	Description
Filling	Fill a boundary region with a smooth surface
Fill Boundary Curves	Fill 2–4 boundary curves with a NURBS patch
Sections	Loft a surface through cross-section curves
Extend Face	Extrapolate a surface beyond its current boundary
Curve on Mesh	Project a sketch curve onto a mesh surface
Blend Curve	Join two edges with a smooth blending curve