[OpenLayers-Dev] 2.12-dev - Delay in tile hiding

Andreas Hocevar ahocevar at opengeo.org
Wed May 15 01:31:31 PDT 2013


For opaque layers, it should not matter what delay you use. But for
transparent layers, to get a good visual experience, you have two
options:

1) Set the removeBackBufferDelay to 0. Can cause flicker, and will
only solve the problems if all tiles are delivered very fast so they
appear in the same rendering pass.

2) Configure your layer with transitionEffect set to 'map-resize'. If
the transparent layer is an overlay, the new base layer tiles will
cover the whole map and you will not see old resolution tiles from the
overlay layer during loading.

Does this address your concerns?

Andreas.

On Wed, May 15, 2013 at 4:43 AM, Tim-Hinnerk Heuer <th.heuer at gmail.com> wrote:
> To answer my own question:
>
> I found that this can be worked around by changing the
> removeBackBufferDelay
> in the WMS Options:
>
> var options = {/*...*/}
> // ...
> options.removeBackBufferDelay = 0;
> OpenLayers.Layer.WMS(description, url, params, options);
>
> The delay is supposed to fix a flicker, which I didn't notice. So, if you
> have flicker problems, the default is 2500, but I would make it less than
> that.
>
> Comments welcome.
>
> Cheers,
> Tim
>
> Tim-Hinnerk Heuer
>
> Twitter: @geekdenz
> Blog: http://www.thheuer.com
>
>
> On 15 May 2013 13:09, Tim-Hinnerk Heuer <th.heuer at gmail.com> wrote:
>>
>> To clarify:
>> I tried looking into the tweening of the zoom and turning it off and
>> playing with the settings. I even turned off tweening for panning. But both
>> things didn't change this behavior while the tweening was visibly off.
>>
>> Any hints?
>>
>> Cheers,
>> T
>>
>> Tim-Hinnerk Heuer
>>
>> Twitter: @geekdenz
>> Blog: http://www.thheuer.com
>>
>>
>> On 15 May 2013 13:07, Tim-Hinnerk Heuer <th.heuer at gmail.com> wrote:
>>>
>>> Hi,
>>>
>>> We have a problem with the latest development version of OL. While it
>>> fixed the problem in IE10 where the map was tearing, it now has another
>>> problem:
>>>
>>> When zooming, our top level layers' tiles are hidden with a significant
>>> amount of delay. This results in it feeling very slow even though our WMS
>>> delivery is very fast. In fact you can see the zoomed in tiles while the
>>> fuzzy tiles that are at a smaller scale are still displayed. After about 3-5
>>> seconds they get hidden correctly, but I think they should be hidden already
>>> at the time the larger scale is displayed.
>>>
>>> I hope this makes sense as I find it hard to put this into words.
>>>
>>> Any help much appreciated. I don't mind fixing it myself, but I don't
>>> know where to even look for this.
>>>
>>> Thanks,
>>> Tim
>>> Tim-Hinnerk Heuer
>>>
>>> Twitter: @geekdenz
>>> Blog: http://www.thheuer.com
>>
>>
>
>
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-- 
Andreas Hocevar
OpenGeo - http://opengeo.org/
Expert service straight from the developers.


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