[mapserver-users] Mapserver usage with commercial vendors data

[thomas bonfort]

Paolo,

On Fri, Apr 29, 2011 at 15:19, Paolo Crosato <paolo.crosato at ubiest.com> wrote:
> Hi,
>
> I work for an LBS based company, we have our own proprietary rendering
> engine for producing maps, and we work mainly with data from Navteq and
> Teleatlas. Presently our rendering engine is behind the competition in terms
> of visual quality (we have a bad support for antialiasing, label names with
> both native and transliterate names are missing, and so on). Introducing new
> features in our current rendering architecture would require quite a lot of
> coding and re-engineering, so we are looking for alternative renderers,
> possibly open sourced. During this research project I came across Mapserver,
> and it seems it would suit our needs in terms of high quality rendering and
> customization.
> However, there are still some open issues, mainly questions, I'd like to
> ask.
>
> In regards to rendering:
> 1) Is there any way to align labels in different encondings for the same
> city? I mean something like writing Москва́ and Moskvá vertically aligned,
> like on Google Maps.
MapServer itself currently only supports a single label per feature,
but it does support label wrapping on specific characters so you can
pass it both Москва́ and Moskvá with a bit of database scripting.
You'd probably have to use utf8 encoding and have a font that supports
all international characters, but that shouldn't be a problem.
Extending mapserver so it supports multiple labels per feature could
also be a possible solution.

for the wrapping method, supposing you have a label_int (Москва́) and
label_en (Moscow) fields, you'd use something like "select id,
the_geom, label_int||'#('||label_en||')' as label from mytable" in
your data statement, and then

LABELITEM "label"
LABEL
 ENCODING UTF8
 WRAP '#'
 ALIGN CENTER
 ....
END


> 2) Is there any plan to support 2.5D rendering for buildings?
There's a bug open for that in the bug tracker, with no concrete
follow-up recently due to lack of funding and/or developper interest.
Adding such support would be feasible.


> In regards to working with high loads of data:
> 1) We render our maps from data provided by vendors like Navteq, and they
> have a lot of details and features. Is there anyone working in the same
> field, who could share some of his experience?
building a relatively complete mapfile for navteq data isn't a
daunting task, although getting everything to display correctly at all
scales can be time-consuming.

> 2) Is it more efficient to work with PostGis/Oracle Spatial or with
> shapefiles? I suppose the former would be faster, since shapefiles provided
> by Navteq would require about 100gigs for Europe only, just to store the
> data.
Indexed shapefiles will be slightly faster than postgis, but the
flexibility you gain by being able to do "complex" queries with
postgis (like ordering the data to get most important ones to show up
first, etc...) is largely worth the slight overhead. I'd say that if
you want high quality map rendering, postgis is going to be a must,
otherwise shapefiles will do. (I have no experience with oracle)

> 3) In regards to the hardware, I reckon we would need at least one
> workstation dedicated to rendering. Currently we are hosting our rendering
> service on dual Xeon (quad core), with 16G of ram and SAS arrays of hard
> disks, would one server like this be ok or would it be better to have more
> machines, especially if planning to use RDBMS to hold the data? I'm asking
> this because with currently work with detailed data from Europe, North and
> South America, so it's quite a lot of stuff :)
>From my tests in these scenarios, the db backend is the bottleneck, so
you can beaf that one up as much as you can (i.e. lots of ram and ssd
disks). A fast cpu and a reasonable amount of memory for the rendering
host can do no harm, although that is a less important factor from my
testing.

regards,
thomas