Here we are halfway into the Inventor 2020 phase and there has been little-to-no discussion about the unexpected gem… Unwrap.

Why the silence? Is the feature not very good? was Autodesk to late to the market? Does no one need this functionality?

I know that when I showed it to a group of industrial equipment mechanical engineers it went over with a collective thud. Over the years, I’ve only run into the need for this a handful of times. So it definitely would seem to be aimed for a more niche area of design.

This feature is legit. For the first revision, it works extremely well, so it can’t be an issue with the feature not being good. I have heard over the years rumblings about the need to unroll a non-sheet-metal surface. I’m thinking manufacturers of composite materials would love this?

Unwrap a Face

Use Unwrap to create planar surfaces by “unwrapping” (flattening) selected faces from a part. The result is a single merged surface or multiple coplanar surfaces.

Unwrapping a face

The unwrapped surface is associative to the source faces. This means as you change the model, the unwrapped surface updates with it.

Use this to create flats of faces that cannot be flattened with Unfold or the Sheet Metal Flat Pattern feature. Unwrap does not use bend calculations! Meaning, there is no correction applied to account for stretching or shortening of the surface.

The Process

With the command active select one or more contiguous faces. To make it a bit easier in the selection, enable Auto Face Chain to select multiple faces with a single selection.

Controlling the Position

The result is inconsistent with other features and is a bit unexpected. Sheet Metal pushes the flat pattern to its own window, nailboarding is done within a drawing, but with Unwrap it places the surface on top of the model. Therefore you need to select the desired position during creation.

With Position at Origin enabled, Inventor inserts the unwrapped surface to the closest point of the first selected face. Select Clear Selections to pick a new Origin point.

With Position at Origin disabled, Inventor inserts the unwrapped surface at the XYZ model origin. Use the manipulators to orient and reposition the surface.

Managing the Output

Use Linear Result to select contiguous edges to remain straight.

Select Rigid Result to select contiguous edges to remain rigid. For example, selecting a circular edge maintains the circular shape when unwrapped.

Enable Merge Result Body to create the flattened output as a singular surface. When disabled, the output is a singular surface with multiple faces.

The preview shows both a surface mesh and a heat map. The heat map shows areas of low deformation/tension (blue) and high deformation/tension (red). If you want to see the heat map again, edit the feature.

What’s in the View Representation?

As the unwrapped surfaces become part of the model, it would cause issues with creating drawings if you couldn’t isolate the flattened surfaces. View Reps to the rescue!

Within the Unwrap dialog, within the Advanced Settings, enable Create Dedicated View Representation. This new view rep shows only the flattened surface. Extremely useful in isolating the object and for documentation.

To use this in a drawing, select the new View Rep during view creation.

The Verdict?

The good… it flattens anything and everything including the kitchen sink. It is easy to use, even the first time.

The bad… as it generates the result over top of the existing model the results are unexpected and inconsistent with other environments and features within Inventor. Also, you need to edit the feature to see the hot and cold zones.

The verdict? Do not let the output derail you, use this feature, when you need it.

Live and in Action

Inventor 2020 Unwrap

Feature Photo by Andrew Neel on Unsplash