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Mon Feb 21 09:46:28 CET 2011


True, if you need orientation matrices you have to convert the data,
but this conversion is still faster (depending on the programming)
than reading and writing the data itself.

So I expect that it will take loger for mbdyn to write the full
orientation matrix into a file plus the time fot blender to parse the
file
than to write and parse just the euler angles and do the conversion
internally.

Additionally as Patrick already metioned one motivation for him to
develop the netcdf interface was smaller file size. It would make little
sense if one compensates this advatange by an orientation format which
needs three times more disk space.

Jens


=3D=3D=3D=3D=3D=3D=3D Pierangelo Masarati wrote: =3D=3D=3D=3D=3D=3D=3D=20

Doug Baldwin wrote:
>> The position and orientation of the nodes in NetCDF are structured as
>> follows:
>>
>> * node.struct.<label>.X contains the position of the node, in the=20
>> appropriate reference frame;
>> * node.struct.<label>.R contains the orientation matrix of the node,=20
>> in the appropriate reference frame;
>> * node.struct.<label>.Phi contains the orientation vector describing=20
>> the orientation of the node, in the appropriate reference frame;
>> * node.struct.<label>.E contains the Euler angles describing the=20
>> orientation of the node, in the appropriate reference frame;
>>
>> Note that only one of R, Phi, or E are present, depending on the=20
>> requested description of the orientation of the node (see structural=20
>> node, Section 6.1, and default orientation, Section 5.2.10).
>=20
> Oh, I somehow got the impression that NetCDF would have only one=20
> standard format for orientation. If all formats are to be carried into

> NetCDF, then it would appear that code written to support all=20
> orientation formats for .mov would be fully applicable to NetCDF
files.

Many formats are possible, but only one at a time will be generated, to
avoid storing trivially redundant info.  So, much like with textual
output, one could choose to use orientation matrices, at the cost of
three times larger database occupation; on the other hand, if Blender
requires the orientation matrix, this would save a conversion all times
the file is loaded/interpreted.

Cheers, p.


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