IfcOpenShell ObjectPlacement

Question

I have the following data:

<IfcSpace id="02e6ey$yf0S8C4bZUVTUao" Name="BRA-0101" ObjectPlacement="-0.2448 0.969574 0 0 -0.969574 -0.2448 0 0 0 0 1 0 1.47106e+08 6.61515e+09 29434 1" LongName="TEKNIK" CompositionType="ELEMENT" InteriorOrExteriorSpace="INTERNAL">...</IfcSpace>

Can somebody tell me how I can interpreter the ObjectPlacement part? I need to know what means each number of the attribute. This is a fraction of the code converted from the ifc format to the xml format with the IfcConvert tool from IfcOpenShell

Thanks very much

score 2 · Accepted Answer · answered Jun 08 '18 at 08:42

I am not very familiar with IfcOpenShell, but since the attribute consists out of 16 values my guess would be it is a 4x4 transformation matrix.

 a b c d
 e f g h
 i j k l
 m n o p

With your values:

    -0.2448    0.969574     0 0 
  -0.969574     -0.2448     0 0 
          0           0     1 0 
1.47106e+08 6.61515e+09 29434 1

A 4x4 matrix allows for translation rotation and scaling of an object. If you don't know how matrices work then there are loads of tutorials on matrices available online.

IfcOpenShell ObjectPlacement

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