[mapguide-users] Fwd: Line Snapping

[Maksim Sestic]

Recently coded something similar, for digitizing accidents (points) against
road network. It's really a no-brainer, I implemented it as a web service
backed by MG. Downside - it's relatively slow if you rely on MG+client only.
It redlines snapped points and flushes them back to feature store once
digitizing is over. But you can always intelligently precache targeted
geometry on a client and do some JavaScript mish-mash, for CAD-like
experience.

I guess future enchancements related to MG client speed will have to tackle
problem of client-side data caching.

Regards,
Maksim Sestic



Kenneth, GEOGRAF A/S wrote:
> 
> I would like to see this functionality on the client, for use with 
> inteactive digitization.
> The closest to an actual implementation I have seen is the MapBender 
> project.
> 
> Regards, Kenneth, GEOGRAF A/S
> 
> 
> 
> Maksim Sestic skrev:
>> It's relatively easy to do. Here're the basic steps:
>>
>> 1) Make a Buffer around a point (buffer size = treshold)
>> 2) Find LineStrings intersecting a Buffer
>> 3) If no LineStrings were found, then return original point (or whatever)
>> 4) Enumerate each LineString vertex to see which one is closest to the
>> point
>> (distance comparer)
>> 5) Return closest LineString vertex as a "snap" point
>>
>> Regards,
>> Maksim Sestic
>>
>>
>>
>> Wind wrote:
>>   
>>> hello everyone: Has anyone done any snapping point to line in mapguide
>>> enterprise?
>>>
>>> ---------- Forwarded message ----------
>>> From: Wind <sherwin.luna at gmail.com>
>>> Date: Dec 18, 2007 11:38 AM
>>> Subject: Re: [mapguide-users] Digitizing demo
>>> To: mapguide-users at lists.osgeo.org
>>>
>>>
>>>
>>> hello everyone: Has anyone done any snapping point to line in mapguide
>>> enterprise?
>>>
>>>
>>>
>>> BradM wrote:
>>>     
>>>> Hello all:  Digitizing new point, line and polygon features is critical
>>>> for mapping features on the community mapping network at www.cmnbc.ca.
>>>> Does anybody have digitizing tools working in a demo that I can view?  
>>>> Is
>>>> anybody interested in developing the tools to make them really
>>>> efficient?
>>>> We need tools that  give added functionality for editing,  creating new
>>>> points by adding a distance and a bearing from one point to the next,
>>>> creating shapefiles, downloading shapefiles, snapping points to lines
>>>> and
>>>> more....
>>>> thanks
>>>>
>>>>       
>>> --
>>> View this message in context:
>>> http://www.nabble.com/Digitizing-demo-tp4127680s16610p14377506.html
>>> Sent from the MapGuide Users mailing list archive at Nabble.com.
>>>
>>> _______________________________________________
>>> mapguide-users mailing list
>>> mapguide-users at lists.osgeo.org
>>> http://lists.osgeo.org/mailman/listinfo/mapguide-users
>>>
>>> _______________________________________________
>>> mapguide-users mailing list
>>> mapguide-users at lists.osgeo.org
>>> http://lists.osgeo.org/mailman/listinfo/mapguide-users
>>>
>>>
>>>     
>>
>>   
> 
> _______________________________________________
> mapguide-users mailing list
> mapguide-users at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/mapguide-users
> 
> 

-- 
View this message in context: http://www.nabble.com/Fwd%3A-Line-Snapping-tp14451050s16610p14467864.html
Sent from the MapGuide Users mailing list archive at Nabble.com.