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# Why do the .err file and .idf/.osm files use a different origin to reference vertices?

Hi, I'm trying to troubleshoot the following error:

* Warning * CalculateZoneVolume: The Zone="0924-CORRIDOR-TZ" is not fully enclosed. To be fully enclosed, each edge of a surface must also be an edge on one other surface. * ~~~ * The zone volume was calculated using the floor area times ceiling height method where the floor and ceiling are the same except for the z-coordinates. * ~~~ * The surface "SURFACE 1614" has an edge that is either not an edge on another surface or is an edge on three or more surfaces: * ~~~ * Vertex start { 32.7536, 2.5467E-002, 35.3568} * ~~~ * Vertex end { 33.9728, 2.1372, 35.3568}

When I find the same surface in the .osm and .idf files the vertices are listed with the following coordinate:

**2.02565, 10.36955, 3.6576, !- X,Y,Z Vertex 1 {m}

2.02565, 12.80795, 3.6576, !- X,Y,Z Vertex 2 {m}

*0, 12.80795, 3.6576, !- X,Y,Z Vertex 3 {m}*

0, 10.36955, 3.6576; !- X,Y,Z Vertex 4 {m}**

The discrepancy in coordinates is making troubleshooting difficult. Does anyone know which origin each coordinate system is based on?

Thanks

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The coordinates reported in the output will always be absolute (or world) coordinates after all coordinate transformations.

The input file coordinates in this case are likely relative coordinates. You can confirm that by searching for the GlobalGeometryRules object. With relative coordinates, the final absolute coordinates are affected by the Zone "Origin" and "Direction of Relative North" and the Building "North Axis". If the north axis rotations are zero for both the zone and building, then absolute surface coordinates are equal to the original surface coordinates plus the zone origin coordinates.

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Makes sense. Thanks for that!

( 2018-10-11 20:04:57 -0500 )edit