[FWTools] Interlis driver, arcs interpolation

[Andreas Neumann]

The support of arcs (and potentially also other curve types) is 
definitely on the rise. Currently there aren't many tools that properly 
support them. In Switzerland all survey data usually contains arcs.

I think it is important that future tools improve their support of arcs 
and potentially also quadratic and cubic spline curves. These are very 
important and quite important in desktop mapping/cartography. Maybe not 
in the US and North-America, but definitely in Middle-Europe and 
Switzerland. I am aware that while it is possible to store arc curves 
now in Postgis, not all of the algorithms already properly support them. 
But given that more and more data formats now storage of arcs and other 
curves I think it would be very useful if a future version of OGR would 
support them. At the german Fossgis in April in Freiburg I talked to 
Markus Neteler from the GRASS team about curves in GRASS. He told me 
that they will look into curve support for GRASS 7. No guarantees of 
course, but the demand for curve support is definitely rising.

Andreas

Frank Warmerdam wrote:
> mj wrote:
>> Hello,
>> in interlis we have data type polyline with straight and arcs, the 
>> ogr2ogr driver interpolate arcs by a given degree ( 1 degree default ).
>> In postgis with newer version ther is a data type Compounds, it is 
>> possible to tell to ogr2ogr to not interpolate arcs but to import 
>> polylines as
>> compunds data type?
>
> Mario,
>
> No, there is no mechanism for this.  OGR does not support true arcs.
>
> I had no idea that postgis now supports curved arcs.  I'm clearly going
> to have to do some research before I do my postgis geometry talk at PG 
> Con!
>
> Best regards,


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Andreas Neumann
Institute of Cartography
ETH Zurich
Wolfgang-Paulistrasse 15
CH-8093  Zurich, Switzerland

Phone: ++41-44-633 3031, Fax: ++41-44-633 1153
e-mail: neumann at karto.baug.ethz.ch
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