IFC (2x3) vs IFC Compressed vs IFC-Optimizer vs IFCzip etc.

[Anonymous]

Hi!
Does anyone know what the difference there are with the several ifc-formats?
If I'm publishing a normal IFC 2x3 and run a Solibri IFC-Optimizer, publishing an IFCzip, publishing an IFC compressed, they all come out with different file sizes. What do you prefer? is there any compressed ifc files I should skip? What kind of data is getting compressed? Are the geometries 100% the same on all these formats?

regards
Johan

[Christophe Fortineau]

Hi Johan,

IFCzip are like zip folder but specially for IFC model.
Most of BIM software are able to read and open IFCzip like IFC files.
I use IFCzip about sending this kind of file through into an email.
The geometries are 100% the same between IFC and IFCzip, The principle is to reduce the space occupied on the digital medium without loss of quality.

[Podolsky]

IFC file is a text file, that has IFC commands, describing building geometry. You can open IFC in text editor and actually read it. But because this is a script, automatically generated by program, it can be large, to compare any other 3D binary formats. Solibri optimiser removes unnecessary or repetitive data from the script, this way it reduce the file size. I don’t know how exactly Solibri optimise the file, but you can check by simple comparing original and optimised ifc in notepad. I can imagine, that original file can describes the layer name for each element, when during optimisation Solibri can set layer name once and after include into group all elements in this layer. Something like that. Maybe it also removes undefined properties.