Feature Request: “Smooth or Flat Interior Option” for the Shell Command

[cklyons99]

Feature Request: “Smooth or Flat Interior Option” for the Shell Command Summary

Add an option in the Shell command to allow users to generate a simplified or flat interior wall instead of a fully conformal offset of the outer surface. This would provide a faster, cleaner, and more print-friendly inner geometry for organic or detailed models created from Form (T-Spline) or Surface bodies.

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Current Behavior

• The Shell tool performs a mathematically exact inward offset of the outer BRep surfaces.

• All exterior details (bumps, waves, embossing) are carried into the interior wall, resulting in a highly complex inner surface.

• For 3D printing, this often increases print time, uses extra filament, and can cause poor bridging or adhesion at steep internal overhangs.

• Users who want a smooth, flat inner wall must manually reconstruct it using Sketch + Extrude or Surface + Stitch workarounds.

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Proposed Enhancement

Add a new option within the Shell dialog:

🟢 Interior Simplification Mode:

• “Conformal” (current behavior)

• “Smoothed” (averaged curvature)”

• “Flat Interior” (planar or simple revolved wall)

When “Flat Interior” is selected, Fusion would:

• Offset only the base plane if present.

• Create a simple cylindrical or planar inner cavity following the overall bounding contour.

• Maintain uniform wall thickness while ignoring local exterior surface detail.

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Benefits

• Dramatically simpler interior geometry for complex sculpted bodies.

• Reduced print time and filament usage for FDM prints.

• Cleaner G-code paths, fewer bridging artifacts.

• Faster shelling operation for large or high-curvature T-Spline conversions.

• Eliminates the need for manual “flatten-interior” workflows with additional sketches or surfaces.

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Example Use Cases

• Organic 3D-printed planters, vases, or bowls where exterior form matters but interior smoothness is desired.

• Sculpted lampshades or art pieces modeled in the Form workspace.

• Mechanical covers or housings where interior detail offers no functional benefit.