[mapserver-users] The Case of the Disappearing Roads

Tue Aug 13 02:27:50 PDT 2013

I just had a look, and committed a fix that works for me in
https://github.com/mapserver/mapserver/issues/4259 (will be in 6.2.2
and 6.4.0)

--
thomas

On 13 August 2013 10:49, thomas bonfort <thomas.bonfort at gmail.com> wrote:
> Joseph,
> This does indead sound like a bug in tile4ms, and a quick test locally
> showed I was also unable to create a valid tileindex with tile4ms.
> That said, given the (absence of) activity around tile4ms (be it in
> code maintenance or user feedback), I would highly recommend to do as
> Jukka pointed out, that is to use the orgtindex command.
>
> regards,
> thomas
>
> On 12 August 2013 21:22, Jeff McKenna <jmckenna at gatewaygeomatics.com> wrote:
>> For good karma (think of it as a way to thank Thomas and others for
>> tackling these questions) since you have a problem dataset handy, you
>> could create a tiny one or two features sample, with one layer, and
>> package all that in an archive with a README.txt and champion this
>> change through the tickets you mentioned.
>>
>> Thanks!
>>
>> -jeff
>>
>>
>> --
>> Jeff McKenna
>> MapServer Consulting and Training Services
>> http://www.gatewaygeomatics.com/
>>
>>
>> On 2013-08-12 4:14 PM, Joseph Marlin wrote:
>>> I am indeed using tile indices. I didn't think there would be any problem with that step, but just to be sure I went ahead and checked. They all looked ok, but I noticed that all the features that use tile indexes were the exact features that aren't showing up- small roadways, highway shields, etc. This was highly suspicious, and so I did a lot of digging.
>>>
>>> I recreated all the index shape files, this time using an old version of the tile4ms and shptree utilities that I had fortunately saved when I generated the map in 2011, and found that tileindex shapefiles were no much larger, and the map was rendered correctly!
>>>
>>> So, all I can say for sure is that the current version of tile4ms and shptree definitely did not work. This issue has been reported at least twice before it seems,
>>> http://trac.osgeo.org/mapserver/ticket/4259
>>> http://www.mail-archive.com/mapserver-users@lists.osgeo.org/msg17207.html
>>>
>>> And I guess it is worth noting that this problem is still present in the latest version (MapServer version 6.2.1 OUTPUT=PNG OUTPUT=JPEG SUPPORTS=AGG SUPPORTS=FREETYPE SUPPORTS=ICONV INPUT=JPEG INPUT=SHAPEFILE).
>>>
>>> Thanks so so much for your help! Let me know if you need further info.
>>> Joseph
>>>
>>>
>>>
>>> ----- Original Message -----
>>> From: "thomas bonfort" <thomas.bonfort at gmail.com>
>>> To: "Joseph Marlin" <jmarlin at saucontech.com>
>>> Cc: "MapserverList OSGEO" <mapserver-users at lists.osgeo.org>
>>> Sent: Saturday, August 10, 2013 3:18:03 AM
>>> Subject: Re: [mapserver-users] The Case of the Disappearing Roads
>>>
>>> Another thing to check: are you using a tileindex to reference your
>>> shapefiles, and if so, is the tileindex up-to-date (i.e. does it
>>> reference all your shapefiles).
>>>
>>> --
>>> thomas
>>>
>>> On 9 August 2013 20:04, Joseph Marlin <jmarlin at saucontech.com> wrote:
>>>> Thanks Thomas for the idea. I think I understand what you're asking. We pre-render all our tiles though, so while the screenshots are indeed showing a javascript viewer, that viewer is simply loading the prerendered images, retrieved from tilecache. And I have made sure that it isn't TileCache storing old tiles.
>>>>
>>>> ----- Original Message -----
>>>> From: "thomas bonfort" <thomas.bonfort at gmail.com>
>>>> To: "Joseph Marlin" <jmarlin at saucontech.com>
>>>> Cc: "MapserverList OSGEO" <mapserver-users at lists.osgeo.org>
>>>> Sent: Friday, August 9, 2013 1:54:41 PM
>>>> Subject: Re: [mapserver-users] The Case of the Disappearing Roads
>>>>
>>>> Joseph,
>>>> are the images you are posting a direct result of a getmap request
>>>> (i.e. with width=1007&height=454), or are they a screenshot of a
>>>> javascript client that is doing tiled requests to mapserver?
>>>> If those are tiled requests, are your layer/class minscale/maxscale
>>>> settings set to the exact values of your requested resolutions (i.e.
>>>> their might be some rounding errors in that case that make a
>>>> scale-dependant class appear or disappear based on floating point
>>>> rounding errors).
>>>>
>>>> --
>>>> thomas
>>>>
>>>> On 9 August 2013 19:03, Joseph Marlin <jmarlin at saucontech.com> wrote:
>>>>> The Case of the Disappearing Roads
>>>>>
>>>>> We create shapefiles with SQL querying world data that's been loaded into a PostgreSQL database. A python script requests tiles from mapserver at different zoom levels, and we generate the entire map like that.
>>>>>
>>>>> Now, at the sixth zoom level, level 3 roads (medium size roads) should be rendered. However, they are actually rendered only in a small section of the world, a box bounded by Toronto in the northwest, Cleveland in the southwest, and the Atlantic in the east. Elsewhere, level 3 roads are not rendered at all.
>>>>>
>>>>> As you can see in this image: http://i.imgur.com/6McvGOJ.png, the small gray roads, level 3 roads, (and highway shields, for that matter) that are visible on the top half suddenly stop being rendered by mapserver.
>>>>>
>>>>> In all the following more zoomed in levels, no roadways smaller than level 2 are rendered at all anywhere, as you can see here: http://i.imgur.com/8MTcPoi.png. I've verified that the shapefiles contain the data on the smaller roads as I have viewed them just fine with QGIS, as you can see here: http://i.imgur.com/S3W3Iy8.png
>>>>>
>>>>> I'm so confused as to what could possibly make roads disappear midway through a level. If it was a problem with my mapfile, why would they show up in part of Northeast US, but not anywhere else? Where do I even start looking to solve this?
>>>>>
>>>>> Thanks so much!
>>>>>
>>>>> Additional info:
>>>>> SRS: EPSG:900913
>>>>> Zoom levels: 19567.8792375, 9783.93961875, 4891.969809375, 2445.9849046875, 1222.99245234375, 611.496226171875, 305.7481130859375, 152.87405654296876, 76.43702827148438, 38.21851413574219, 19.109257067871095, 9.554628533935547, 4.777314266967774, 2.388657133483887,  1.1943285667419434, 0.5971642833709717, 0.29858214168548586
>>>>> Bounding box: -20037508.3427892,-20037508.3427892, 20037508.3427892,20037508.3427892
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