# Union btw objecrs extruded from spline and lines

**URL:** <https://discourse.shapr3d.com/t/union-btw-objecrs-extruded-from-spline-and-lines/41095>\
**Category:** Modeling Questions\
**Created:** [June 21, 2026, 12:07pm UTC](https://discourse.shapr3d.com/t/union-btw-objecrs-extruded-from-spline-and-lines/41095 "2026-06-21T12:07:50Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![TJM](https://avatars.discourse-cdn.com/v4/letter/t/5daacb/32.png) [@TJM](https://discourse.shapr3d.com/u/TJM)\
**Post date:** [June 21, 2026, 12:07pm UTC](https://discourse.shapr3d.com/t/union-btw-objecrs-extruded-from-spline-and-lines/41095/1 "2026-06-21T12:07:50Z")

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applying complex relief features to a flat surface. I’m joining the complex objects to the planar surface with “union”. The issue becomes apparent after the union is executed in the following way: the smooth curves of the complex objects I’ve extruded from spline sketches suddenly become facets. The base objects I’ve I’m creating the union with is extruded from a rectangle. In some cases, the resulting union even has the vertical walls “peeling” off from the curve. Is there a simple fix for this?