Troubleshooting Surfaces

Surfaces do not show when part is shaded

Set option shade_surface_feat yes

After creating a surface it is not visible on screen?

Check that the layers containing surface features/ quilts are unblanked.

No hidden line removal of surfaces in drawings

Set option hlr_for_quilts yes

Surface fails when I mirror it using Copy, Mirror?

Use Surface, Transform, and Mirror to mirror surfaces. Copy Mirror is not meant for surfaces especially when the surface is constructed using datum curves.

Boundary Surfaces

Defining boundary conditions causes feature failure

If you have successfully defined the boundaries and previewed a surface, but after setting the boundary conditions you are unable to preview the surface then check the following issues.

-check that the construction curves/ edges used by the boundary surface have same end conditions (tangency/ normal) as the intended boundary condition.

-check whether adjacent boundary conditions will conflict where the boundaries meet e.g. at the vertex of two boundaries the surface is trying to satisfy two sets of boundary conditions.

A boundary surface is created with a twist

Boundary surfaces can appear twisted, this tends to be a problem when using closed loops as boundaries or when each boundary has different numbers of entities within the boundary.

From the surface definition dialogue select control points define and select which points should be linked together. If the boundaries contain different numbers of entities either use control points to create blends, or redefine the boundary entities to have the same number of entities (if they are sketched use Geom Tools, Divide).

Reasons why a boundary surface cannot be created

When Pro/Engineer cannot form a boundary surface it can be difficult to find out the cause. Always try Resolve, Investigate, Item Info this often highlight the reason, also try Failed Geom to illustrate what is happening. Here are some of the main reasons.

Boundary condition for a boundary is set to Tangent/Normal when adjacent boundaries are not tangent/normal to selected reference.

Two boundaries cannot be tangential to each other.

Boundaries cannot intersect each other than at each end.

The boundary conditions of two adjacent boundaries conflict with each other.

When two or more directions are defined then the boundaries must form a loop.

Surface created using datum curves as boundaries contain ripples

Avoid using splines to create datum curves, use conic sections

Make all joins between lines/ arcs are tangent


A sweep cannot be created using a 3d curve as the trajectory

Pro/engineer requires a reference plane to orient the sketch and cannot use a 3d datum curve as the trajectory. Typically 3d curves are created using the 'thru points' option.

Sweeps can be created along curved edges which have an adjacent surface. Alternatively the 3d curve can be used if a Swept Blend or Var Sec Swp is used instead of a simple sweep because these two features require additional geometry to orient the sketch plane.


Blend surface is twisted

Check the start point on both sketches is in the right place.

Variable Section Sweeps

Variable section sweep surface has a constant cross-section

This often happens if you use Geom Tools, Use Edge (Offset Edge)

Delete the use edge constraint (the squiggle on the sketch entity)

The other cause is if the sketch has automatically aligned to the trajectory paths.

Align or dimension the sketch to the trajectories. The main trajectory is shown as crossed centerlines. Secondary trajectories are shown as dots.