# Local coordinate system of instances?

**URL:** <https://forum.dynamobim.com/t/local-coordinate-system-of-instances/4948>\
**Category:** Uncategorized\
**Created:** [July 8, 2016, 11:55am UTC](https://forum.dynamobim.com/t/local-coordinate-system-of-instances/4948 "2016-07-08T11:55:42Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![ebr](https://avatars.discourse-cdn.com/v4/letter/e/d6d6ee/32.png) [@ebr](https://forum.dynamobim.com/u/ebr)\
**Post date:** [July 8, 2016, 11:55am UTC](https://forum.dynamobim.com/t/local-coordinate-system-of-instances/4948/1 "2016-07-08T11:55:42Z")

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Hi all.

I have found a lot of threads dealing with this issue but none that actually solve it in a definite way.  
Like this for example: [Bounding Box by Geometry Coordinate System problem](https://forum.dynamobim.com/t/bounding-box-by-geometry-coordinate-system-problem/2421)

- For finding the minimal space boundingbox of an instance, say a window.
- For calculating orientation of instances.
- For transforming instances or getting transformation from instances.

Can we have a node that returns the local coordinate system of an instance object?  
Right now the bounding box only returns a box in the project coordinate system…

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**Author:** ![Vikram\_Subbaiah](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/vikram_subbaiah/32/50797_2.png) [@Vikram\_Subbaiah](https://forum.dynamobim.com/u/Vikram_Subbaiah)\
**Post date:** [July 14, 2016, 6:01am UTC](https://forum.dynamobim.com/t/local-coordinate-system-of-instances/4948/2 "2016-07-14T06:01:52Z")

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There used to be a node called _BoundingBox.ByGeometryCoordinateSystem_ . You need that node.  
Unfortunately, it’s been broken for a while and is being worked on.

> <https://github.com/DynamoDS/Dynamo/issues/2243>

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**Author:** ![Henrik\_Ejnar\_Rasmuss](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/henrik_ejnar_rasmuss/32/11084_2.png) [@Henrik\_Ejnar\_Rasmuss](https://forum.dynamobim.com/u/Henrik_Ejnar_Rasmuss)\
**Post date:** [July 14, 2016, 6:50am UTC](https://forum.dynamobim.com/t/local-coordinate-system-of-instances/4948/3 "2016-07-14T06:50:04Z")

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Its a showstopper for a bunch of our new pipeline tools so its great to know that its being worked on.  
And from reading the link its seems not to far of although it has been quite a while in the making.  
Thanks for the reply!

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**Author:** ![Joseph\_Peel](https://avatars.discourse-cdn.com/v4/letter/j/ce73a5/32.png) [@Joseph\_Peel](https://forum.dynamobim.com/u/Joseph_Peel)\
**Post date:** [August 9, 2016, 4:06pm UTC](https://forum.dynamobim.com/t/local-coordinate-system-of-instances/4948/4 "2016-08-09T16:06:42Z")

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Yes its very irritating this doesnt work…

Found another solution;  
Use Elements.position-rotation node to get the rotation angle of the thing you want to fit a box to.  
Get the objects geometry.  
Rotate the geometry by the angle\*-1, so it is orthogonal.  
Fit a bounding box to the orthogonal geometry.  
Use the correct bounding box to create/size whatever you want.  
Rotate created geometry back to correct angle,  
OR  
Use Set Rotation node to rotate family instances back to the original angle…