Re: [udig-devel] rendering, styles, attributes

[Jérémy DE ROYER <jeremy.deroyer@xxxxxxxxxxxx>]

I'm also interested in the answer.

We plan to start an easy experiment with uDig :
- open shapefiles with the towns and their id as attribute,
- import data from excel files and create maps with points according to
the location given by the town id
- change the renderuing style according to some attreibute values.

Jérémy

> Now that uDig's performance looks pretty good for our purposes, I'd like
> to
> ask a few questions which I haven't been able to answer from reading the
> documentation.
>
> Render style by attribute value: The shapefiles I'm using (e.g. that large
> one with lots of points) have various attributes associated with each
> points.  I'd like to colour the points according to certain attribute
> values (e.g. vehicle_id).  How would I go about doing that in uDig (or can
> you point me to an outline of how I might achieve this with further
> development)?  I can see two paths to achieving this -- first just to have
> the ability to specify a render colour by attribute value, or second to
> split a layer by a given attribute, and then colour each newly-created
> layer manually.
>
> 1-2 years ago we did a fair amount of work on the j2drenderer from
> geotools, to add a more performant selection/modification capability (no
> need to re-render everything just because a few features have changed
> colour/appearance).  In the medium term we would probably want to use
> this,
> so I'm wondering what the path might be to have uDig use the j2d renderer
> (or something similar to that)?  Are the recent "point" performance
> improvements to the shapefile renderer somehow intertwined with the
> lite-renderer being used by uDig, or are they elsewhere in the rendering
> pipeline?  (Note: we'd probably be using a mixture of shapefiles and GML
> data for rendering purposes)
>
> Another question of slightly lesser importance: is uDig's rendering
> pipeline at all suited to the idea of adding a dynamic, animated layer
> (e.g. vehicles moving around a street network, or ships across a river/sea
> network) under some circumstances?
>
> cheers,
>
> Vince.
>
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