# IfcSectionedSpine future

**URL:** <https://forums.buildingsmart.org/t/ifcsectionedspine-future/2816>\
**Category:** Developers\
**Tags:** ifc4, reference-view\
**Created:** [June 30, 2020, 6:27pm UTC](https://forums.buildingsmart.org/t/ifcsectionedspine-future/2816 "2020-06-30T18:27:31Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![claimred](https://avatars.discourse-cdn.com/v4/letter/c/e47c2d/32.png) [@claimred](https://forums.buildingsmart.org/u/claimred)\
**Post date:** [June 30, 2020, 6:27pm UTC](https://forums.buildingsmart.org/t/ifcsectionedspine-future/2816/1 "2020-06-30T18:27:31Z")

</div>

Various curves (IfcTrimmedCurve, IfcPolyLine) essentially are becoming deprecated and IfcIndexedPolyCurve being used everywhere.

IfcSectionedSpined, on the other hand, uses umbrella class IfcCompositeCurve for its construction. Now it seems unclear to me how IfcSectionedSpined geometry should be used in IFC4?

---

<div class="post-metadata">

**Author:** ![igor.sokolov](https://sea2.discourse-cdn.com/flex016/user_avatar/forums.buildingsmart.org/igor.sokolov/32/25_2.png) [@igor.sokolov](https://forums.buildingsmart.org/u/igor.sokolov)\
**Post date:** [July 1, 2020, 11:45am UTC](https://forums.buildingsmart.org/t/ifcsectionedspine-future/2816/2 "2020-07-01T11:45:47Z")

</div>

Good point.  
I see also IfcAlignment declared to use IfcPolyline… should be IfcIndexedPolyCurve