# How to associate A3DTessFaceData with its A3DTopoFaceData in HOOPS Exchange efficiently? **URL:** \ **Category:** HOOPS Exchange\ **Tags:** topology, tessellation\ **Created:** [September 24, 2025, 9:49am UTC](https://forum.techsoft3d.com/t/how-to-associate-a3dtessfacedata-with-its-a3dtopofacedata-in-hoops-exchange-efficiently/4914 "2025-09-24T09:49:43Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![way1632023](https://avatars.discourse-cdn.com/v4/letter/w/cdc98d/32.png) [@way1632023](https://forum.techsoft3d.com/u/way1632023)\ **Post date:** [September 24, 2025, 9:49am UTC](https://forum.techsoft3d.com/t/how-to-associate-a3dtessfacedata-with-its-a3dtopofacedata-in-hoops-exchange-efficiently/4914/1 "2025-09-24T09:49:43Z")
Is there a specific function that can directly associate a face’s tessellation data (`A3DTessFaceData`) with its topological face data (`A3DTopoFaceData`)? I have observed that the tessellation data (`A3DTessBase*`) comes from `A3DRiRepresentationItemData`, which is typically obtained from an `A3DRiBrepModelData`. However, an `A3DTopoFaceData` is not an `A3DRiRepresentationItemData` itself; it’s a sub-level structure within it. Because of this, I tried using `A3DRiRepresentationItemComputeTessellation` on an `A3DTopoFace*` but it failed, as the function requires a parameter of type `A3DRiRepresentationItem*`. The current workaround I’ve found is to build up the hierarchy from the `A3DTopoFaceData` all the way to an `A3DRiBrepModelData` and then call `A3DRiRepresentationItemComputeTessellation`. However, this process is very time-consuming and, crucially, it does not leverage the existing `A3DTessBase*` data that I already have from the Brep model’s tessellation. Is there a more efficient way to achieve this mapping without reconstructing the entire Brep model representation item? Any guidance would be greatly appreciated.