Re: [udig-devel] enabled tilecaching results into rendering problems if

[Jody Garnett <jody.garnett@xxxxxxxxx>]

I wonder if we could "cheat" .... if we saved each tile with its label cache; we could do some kind of label cache merge between on the tiles and then render the labels at the end. In cases where two label caches entries have the same featureid we could get a list; and then take the average of their centroids? (Basically putting the pieces back together that were split across several tiles).

We have not tried meta tiling at this point in time in udig.

Jody

On 28/03/2010, at 7:09 PM, Andrea Aime wrote:

> Jody Garnett ha scritto:
>> I think Emily and Jesse will need to answer you. Emily did put in some time to sort out labeling issues for tiled rendering; currently tiled renderer is fatal on the mac (crashes the JVM) so I have not been testing it myself. I will try again now that we have switch to Eclipse 3.5.2...
> 
> Generally speaking, you cannot have tiling and good label rendering
> at the same time.
> The general trick to reduce labeling artifacts while tiling is to
> "meta tile", that is, generate a 3x3 image and slice it up.
> Of course the label issues will keep on appearing at the "meta tile"
> borders, just makes the artifacts less frequent.
> 
> An approach to get good labels that I've used in OpenLayers is
> to take the style, slice it up and make two, one for labels and
> one for everything else, then render the labels un-tiled and
> the rest tiled. That gives most of the tiling advantages
> without sacrificing decent labeling. Of course it comes with
> some performance overhead as labeled features need to be
> read twice.
> 
> Cheers
> Andrea
> 
> 
> -- 
> Andrea Aime
> OpenGeo - http://opengeo.org
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