# same instance geometries across I3DM tiles

**URL:** <https://community.cesium.com/t/same-instance-geometries-across-i3dm-tiles/5017>\
**Category:** CesiumJS\
**Created:** [January 12, 2017, 4:15pm UTC](https://community.cesium.com/t/same-instance-geometries-across-i3dm-tiles/5017 "2017-01-12T16:15:39Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Arne\_Schilling](https://avatars.discourse-cdn.com/v4/letter/a/6f9a4e/32.png) [@Arne\_Schilling](https://community.cesium.com/u/Arne_Schilling)\
**Post date:** [January 12, 2017, 4:15pm UTC](https://community.cesium.com/t/same-instance-geometries-across-i3dm-tiles/5017/1 "2017-01-12T16:15:39Z")

</div>

can I somehow avoid redefining my instance geometries in I3DM for each tile although I use the same 3D model in each tile?  
Currently I embed instance geometries as binary gltf. Would referencing to an external URL from a library help?

---

<div class="post-metadata">

**Author:** ![sean\_lilley](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/sean_lilley/32/2083_2.png) [@sean\_lilley](https://community.cesium.com/u/sean_lilley)\
**Post date:** [January 13, 2017, 2:04am UTC](https://community.cesium.com/t/same-instance-geometries-across-i3dm-tiles/5017/2 "2017-01-13T02:04:50Z")

</div>

Yes, referencing external gltf’s should do it: [https://github.com/AnalyticalGraphicsInc/3d-tiles/tree/master/TileFormats/Instanced3DModel#gltf](https://github.com/AnalyticalGraphicsInc/3d-tiles/tree/master/TileFormats/Instanced3DModel#gltf)