Dear OpenFlipper friends and developers,
We are just now running into a problem while using the OpenFlipper for topo modelling and model simplification with the Decimater. The point is that geographical coordinates tend to be large numbers, but in some way you can say that the most significant digits are the least significant ones - because they never change throughout a model!
The problem is that once we have "decimated" a model and want to write it out to an OBJ file, the least significant digits are cut off by the C++ automatism of switching to exponential notation if numbers are getting large:
4522765.277 -> 4.52277e006
Which means: rounding to the next 10m occurs - not really acceptable!
Of course we are already practising the workaround of first shifting the coordinates to something lower, then do the OpenFlipper treatment, then shift back. But of course it would be nicer if the OpenFlipper would simply do the output with some explicit fixed formatting. Currently the code that outputs the coordinates in OBJ format is the following:
// Write out vertex coordinates _out << "v " << v[0] <<" "<< v[1] <<" "<< v[2] << std::endl;
This code is at FileOBJT.cc(299). Would it be possible to add some formatting to such output lines, in order to make it easier to work with large coordinate values? Or is there a danger that in such a case there would be people complaining that they are now not any more able to work in picometers properly? ;-)
Regards, Cornelis
_____________________
Cornelis Bockemühl Holcim Group Support Ltd Cement Manufacturing Services Materials Technology Reserve Evaluation and Quarry Planning Im Schachen CH-5113 Holderbank Phone +41 58 858 51 30 Fax +41 58 858 51 51 cornelis.bockemuehl@holcim.com www.holcim.com
Holcim – 100 years of Strength. Performance. Passion.
This e-mail is confidential and intended only for the use of the above named addressee. If you have received this e-mail in error, please delete it immediately and notify us by e-mail or telephone.
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Hi,
we recently added a field controlling the precision to the mesh writers (Currently in the svn only). When you write to a file, uncheck the use defaults checkbox in the save dialog. A new dialog will appear and you can change the precision at the bottom of this dialog.
Best, Jan Möbius
On 01.11.2012 17:28, cornelis.bockemuehl@holcim.com wrote:
Dear OpenFlipper friends and developers,
We are just now running into a problem while using the OpenFlipper for topo modelling and model simplification with the Decimater. The point is that geographical coordinates tend to be large numbers, but in some way you can say that the most significant digits are the least significant ones - because they never change throughout a model!
The problem is that once we have "decimated" a model and want to write it out to an OBJ file, the least significant digits are cut off by the C++ automatism of switching to exponential notation if numbers are getting large:
4522765.277 -> 4.52277e006
Which means: rounding to the next 10m occurs - not really acceptable!
Of course we are already practising the workaround of first shifting the coordinates to something lower, then do the OpenFlipper treatment, then shift back. But of course it would be nicer if the OpenFlipper would simply do the output with some explicit fixed formatting. Currently the code that outputs the coordinates in OBJ format is the following:
// Write out vertex coordinates _out << "v " << v[0] <<" "<< v[1] <<" "<< v[2] << std::endl;This code is at FileOBJT.cc(299). Would it be possible to add some formatting to such output lines, in order to make it easier to work with large coordinate values? Or is there a danger that in such a case there would be people complaining that they are now not any more able to work in picometers properly? ;-)
Regards, Cornelis
Cornelis Bockemühl Holcim Group Support Ltd Cement Manufacturing Services Materials Technology Reserve Evaluation and Quarry Planning Im Schachen CH-5113 Holderbank Phone +41 58 858 51 30 Fax +41 58 858 51 51 cornelis.bockemuehl@holcim.com www.holcim.com
Holcim – 100 years of Strength. Performance. Passion.
This e-mail is confidential and intended only for the use of the above named addressee. If you have received this e-mail in error, please delete it immediately and notify us by e-mail or telephone.
Openflipper mailing list Openflipper@lists.rwth-aachen.de http://mailman.rwth-aachen.de/mailman/listinfo/openflipper
Dear Mr. Möbius,
Thanks for your hint which was very helpful! Having Tortoise SVN, Qt 4.7.4. and Visual Studio 2005 already installed, it took me just a few hours to get the entire OpenFlipper sources to compile on my system - and so I have that option activated and operational here for me now! That solution is more perfect than what I had expected as it even allows the "nanometer modeller" to still work with the same software as the "kilometer modeller".
Regards, Cornelis Bockemühl
_____________________
Cornelis Bockemühl Holcim Group Support Ltd Cement Manufacturing Services Materials Technology Reserve Evaluation and Quarry Planning Im Schachen CH-5113 Holderbank Phone +41 58 858 51 30 Fax +41 58 858 51 51 cornelis.bockemuehl@holcim.com www.holcim.com
Holcim – 100 years of Strength. Performance. Passion.
This e-mail is confidential and intended only for the use of the above named addressee. If you have received this e-mail in error, please delete it immediately and notify us by e-mail or telephone.
openflipper@lists.rwth-aachen.de
-
cornelis.bockemuehl＠holcim.com -
Jan Möbius