[Tilecache] png256 transparency and nodata with raster, mapnik

[Christopher Schmidt]

On Thu, Jan 29, 2009 at 11:21:02AM -0800, Matt Bartolome wrote:
> Hi, this is a tilecache + mapnik question.
> 
> I'm wondering if it is possible to set a nodata value to transparent
> when rendering raster data with png256 in tilecache. I wanted to use
> the png256 extension in my tilecache.cfg but when the bounding box
> exceeds the raster I get a black boundary for the missing data. 

This functionality does not exist in Mapnik, and would need to be fixed
there. It is not possible to do this at this time.

Regards,
-- 
Christopher Schmidt
MetaCarta