[mapserver-dev] Request for review/comments on RFC 85 (Contour Layer Rendering)

[Havard Tveite]

I am not sure if contour generation should be a job for Mapserver,
but if we decide to implement it, I think there is a need for
processing directives for "smoothing" / generalisation.
It should be possible to specify the level of "smoothing" for the
DEM as well as for the resulting contours.
Smoothing levels could be specified as the maximum deviation
allowed from the "original".
Contour "smoothing" / generalisation needs to pay attention to
neighbouring contours / topology, so that contours don't cross
after smoothing.

Possible processing directives for a DEM tolerance of 25 units
(xyz) and contour tolerance of 10 units (xy):
PROCESSING "DEM_TOLERANCE"=25"
PROCESSING "CONTOUR_TOLERANCE=10"
They could be made scale dependent in the way that is suggested
in the RFC.
"TOLERANCE" might not be the best word - "GENERALIZATION"
is also be a possibility.

It would also be good to choose an approach that will not
make it impossible to use a point layer (xyz or xy+height
attribute) as a data source.

Håvard

On 9/20/2012 5:40 PM, Alan Boudreault wrote:
> Hi devs,
>
> I'd like to request some review on a pending RFC regarding support for contour layer rendering.
>
> Please see https://raw.github.com/mapserver/docs/master/en/development/rfc/ms-rfc-85.txt
>
> The official rfc page should be updated in about a hour.
>
> http://mapserver.org/trunk/development/rfc/ms-rfc-85.html.
>
> Thanks,
> Alan