Re: [Qgis-developer] Suppress rendering of small features
Hi all I also think dynamic scale-dependent simplification would be very nice but for me ONLY if we can preserve topology when simplifying. If not, it would lead to very uggly results cf http://strk.keybit.net/blog/ for example +1 for optionnaly remove small feature though, this will be good too ! 2013/9/12 Vincent Mora vincent.m...@oslandia.com Hi, I did something somewhat similar to solve #4819 in Jully (Identify Features tool is slow with complex/big features) and Matthias asked me to do the same thing for the rubber-band. In polygon contours, points that are less than a pixel apart from the previous point are not drawn. That improved (dramatically) the rendering speed. Vincent On 12/09/2013 13:03, Sandro Santilli wrote: On Thu, Sep 12, 2013 at 08:51:43AM +0200, Andreas Neumann wrote: Hi, As I understand, the feature to suppress small/large features would be optional. Another interesting thing would be to simplify features when you zoom out. Maybe simplifying would be quicker than rendering thousands of unnecessary vertices. Optionally this could also be outsourced to the database - many databases support simplification on the db level. I don't know if it would really speed up things. One would have to test. I've done this for mapnik and it worked pretty nicely: http://blog.cartodb.com/post/20163722809/speeding-up-tiles-rendering --strk; ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] Suppress rendering of small features
Hi, We just discussed this and concluded, that the safest solution would be to only simplify for rendering and only when the resolution is small enough, that only points which will be painted on top of each other will be simplified away. (And then we should make some tests and see if it's actually worth it...) Matthias On Fri 13 Sep 2013 04:33:45 PM BST, kimaidou wrote: Hi all I also think dynamic scale-dependent simplification would be very nice but for me ONLY if we can preserve topology when simplifying. If not, it would lead to very uggly results cf http://strk.keybit.net/blog/ for example +1 for optionnaly remove small feature though, this will be good too ! 2013/9/12 Vincent Mora vincent.m...@oslandia.com mailto:vincent.m...@oslandia.com Hi, I did something somewhat similar to solve #4819 in Jully (Identify Features tool is slow with complex/big features) and Matthias asked me to do the same thing for the rubber-band. In polygon contours, points that are less than a pixel apart from the previous point are not drawn. That improved (dramatically) the rendering speed. Vincent On 12/09/2013 13:03, Sandro Santilli wrote: On Thu, Sep 12, 2013 at 08:51:43AM +0200, Andreas Neumann wrote: Hi, As I understand, the feature to suppress small/large features would be optional. Another interesting thing would be to simplify features when you zoom out. Maybe simplifying would be quicker than rendering thousands of unnecessary vertices. Optionally this could also be outsourced to the database - many databases support simplification on the db level. I don't know if it would really speed up things. One would have to test. I've done this for mapnik and it worked pretty nicely: http://blog.cartodb.com/post/20163722809/speeding-up-tiles-rendering --strk; ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org mailto:Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org mailto:Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] Suppress rendering of small features
Hi, I have been following Vincent's solution since I funded #4819 resolution. Pruning all vertexes under screen resolution is really a nice idea. I wasn't sure that pruning vertex was less cpu consuming than rendering them, and now it's proved. just use a very large object, and do a identify on it to see.. I think that on the fly vertex pruning is a better definition than simplification process, since the rendering must be the same when viewed on screen or on a paper output. That bug #4819 occured to be a blocker to us in since new hydro-geological datasets have a crazy vertex density , and anticipates even more precise resolutions. All datasets will be derived from high resolution data, but we always need to render them with small scales. I'm wondering if we could something close to raster resampling, with zoom-out/zoom-in factor and resampling methods (nearest neighbour, bicubic, average). User could choose the rendering fuzziness factor when zoomed out. Zoom in is probably something user do not wish (this could lead to bad interpretations.) Another possible direction I'm thinking of, is having the possibility to have scale dependent, or better rule based, geometry field. Ie, use full geometry field when zoomed in, and let user calibrate if other geometry fields could be used when zoomed out. This is far less generic and elegant than vertex pruning, but could be usefull with spatialDB, and particular datasets... Let us know what strategic direction you choose, and we can be there to support you then. Have good times you all in Brighton. Cheers, Régis -- View this message in context: http://osgeo-org.1560.x6.nabble.com/Suppress-rendering-of-small-features-tp5077397p5077767.html Sent from the Quantum GIS - Developer mailing list archive at Nabble.com. ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] Suppress rendering of small features
Hi, As I understand, the feature to suppress small/large features would be optional. Another interesting thing would be to simplify features when you zoom out. Maybe simplifying would be quicker than rendering thousands of unnecessary vertices. Optionally this could also be outsourced to the database - many databases support simplification on the db level. I don't know if it would really speed up things. One would have to test. Andreas Am 12.09.2013 07:57, schrieb aperi2007: Not always is preferrable to suppress the small features. Often in our rendering we prefere to substitute a small rendering of kind polygon with a point rendering at lowest scales. This is possible using the Rule-Rendering also is possible to use the rule-rendering to define a rule that in a scale interval and with a dimension interval the feature is render using a point rendering and change in a polygon rendering when the scale grow. Andrea. On 12/09/2013 02:13, Nyall Dawson wrote: Hi all, I've been chatting with Nathan about adding a feature to QGIS which would allow suppression of rendering features smaller than a set threshold for vector layers. (There's already a similar function in the labelling engine Suppress labeling of features smaller than). This feature would come in handy for me for several tables which contain a wide range of very small - very large features, which cause slow rendering at small scales. I'm just checking that if I code this up it's not going to be duplicated effort - Nathan is under the impression that someone else has been talking about adding something similar. Is there currently any plans for a feature like this, or should I get started? Nyall ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] Suppress rendering of small features
On Thu, Sep 12, 2013 at 8:51 AM, Andreas Neumann a.neum...@carto.netwrote: [...] I don't know if it would really speed up things. One would have to test. Programmers waste enormous amounts of time thinking about, or worrying about, the speed of noncritical parts of their programs, and these attempts at efficiency actually have a strong negative impact when debugging and maintenance are considered. We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil. Yet we should not pass up our opportunities in that critical 3%. Donald Knuth ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] Suppress rendering of small features
Hi, How would you define small? I guess something can already be done with scale based visibility, but that needs preprocessing of the data and assigning some kind of size class. On Don 12 Sep 2013 08:51:43 CEST, Andreas Neumann wrote: Hi, Another interesting thing would be to simplify features when you zoom out. Maybe simplifying would be quicker than rendering thousands of unnecessary vertices. Optionally this could also be outsourced to the database - many databases support simplification on the db level. I don't know if it would really speed up things. One would have to test. I did a preliminary analysis for this. I created a view on a postgis DB containing ~17000 line features with the geometry column simplified to 10m in the view. *Non Simplified* ./output/bin/qgis_bench --iterations 20 --width 1024 --height 768 bench-full.qgs iterations: 20 total_avg: 0.4246 total_max: 0.657 total_maxdev: 0.2324 total_min: 0.407 total_stdev: 0.0535176606364665 *Simplified* ./output/bin/qgis_bench --iterations 20 --width 1024 --height 768 bench-simplified.qgs iterations: 20 total_avg: 0.09615 total_max: 0.098 total_maxdev: 0.001849998 total_min: 0.095 total_stdev: 0.000792148975887722 0.42 / 0.09 is more than 400% performance improvement for this simple case. The results of course depend heavily on the particular setting, but I think this looks indeed like a road we should have a look into. (Setup: PostGIS 2.0.3 in a kvm virtual machine on the same physical machine. No styling at all took place on the layer) Matthias Andreas Am 12.09.2013 07:57, schrieb aperi2007: Not always is preferrable to suppress the small features. Often in our rendering we prefere to substitute a small rendering of kind polygon with a point rendering at lowest scales. This is possible using the Rule-Rendering also is possible to use the rule-rendering to define a rule that in a scale interval and with a dimension interval the feature is render using a point rendering and change in a polygon rendering when the scale grow. Andrea. On 12/09/2013 02:13, Nyall Dawson wrote: Hi all, I've been chatting with Nathan about adding a feature to QGIS which would allow suppression of rendering features smaller than a set threshold for vector layers. (There's already a similar function in the labelling engine Suppress labeling of features smaller than). This feature would come in handy for me for several tables which contain a wide range of very small - very large features, which cause slow rendering at small scales. I'm just checking that if I code this up it's not going to be duplicated effort - Nathan is under the impression that someone else has been talking about adding something similar. Is there currently any plans for a feature like this, or should I get started? Nyall ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] Suppress rendering of small features
Could this be done using a rule-based expression through the creation of a variable that returns the pixel-size area of a polygon / pixel-size length of a line? On Thu, Sep 12, 2013 at 3:28 PM, Matthias Kuhn matthias.k...@gmx.ch wrote: Hi, How would you define small? I guess something can already be done with scale based visibility, but that needs preprocessing of the data and assigning some kind of size class. On Don 12 Sep 2013 08:51:43 CEST, Andreas Neumann wrote: Hi, Another interesting thing would be to simplify features when you zoom out. Maybe simplifying would be quicker than rendering thousands of unnecessary vertices. Optionally this could also be outsourced to the database - many databases support simplification on the db level. I don't know if it would really speed up things. One would have to test. I did a preliminary analysis for this. I created a view on a postgis DB containing ~17000 line features with the geometry column simplified to 10m in the view. *Non Simplified* ./output/bin/qgis_bench --iterations 20 --width 1024 --height 768 bench-full.qgs iterations: 20 total_avg: 0.4246 total_max: 0.657 total_maxdev: 0.2324 total_min: 0.407 total_stdev: 0.0535176606364665 *Simplified* ./output/bin/qgis_bench --iterations 20 --width 1024 --height 768 bench-simplified.qgs iterations: 20 total_avg: 0.09615 total_max: 0.098 total_maxdev: 0.001849998 total_min: 0.095 total_stdev: 0.000792148975887722 0.42 / 0.09 is more than 400% performance improvement for this simple case. The results of course depend heavily on the particular setting, but I think this looks indeed like a road we should have a look into. (Setup: PostGIS 2.0.3 in a kvm virtual machine on the same physical machine. No styling at all took place on the layer) Matthias Andreas Am 12.09.2013 07:57, schrieb aperi2007: Not always is preferrable to suppress the small features. Often in our rendering we prefere to substitute a small rendering of kind polygon with a point rendering at lowest scales. This is possible using the Rule-Rendering also is possible to use the rule-rendering to define a rule that in a scale interval and with a dimension interval the feature is render using a point rendering and change in a polygon rendering when the scale grow. Andrea. On 12/09/2013 02:13, Nyall Dawson wrote: Hi all, I've been chatting with Nathan about adding a feature to QGIS which would allow suppression of rendering features smaller than a set threshold for vector layers. (There's already a similar function in the labelling engine Suppress labeling of features smaller than). This feature would come in handy for me for several tables which contain a wide range of very small - very large features, which cause slow rendering at small scales. I'm just checking that if I code this up it's not going to be duplicated effort - Nathan is under the impression that someone else has been talking about adding something similar. Is there currently any plans for a feature like this, or should I get started? Nyall ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] Suppress rendering of small features
Hi Matthias, Thank you for your preliminary results. I think they are encouraging to further look into this issue. Andreas Am 12.09.2013 10:28, schrieb Matthias Kuhn: Hi, How would you define small? I guess something can already be done with scale based visibility, but that needs preprocessing of the data and assigning some kind of size class. On Don 12 Sep 2013 08:51:43 CEST, Andreas Neumann wrote: Hi, Another interesting thing would be to simplify features when you zoom out. Maybe simplifying would be quicker than rendering thousands of unnecessary vertices. Optionally this could also be outsourced to the database - many databases support simplification on the db level. I don't know if it would really speed up things. One would have to test. I did a preliminary analysis for this. I created a view on a postgis DB containing ~17000 line features with the geometry column simplified to 10m in the view. *Non Simplified* ./output/bin/qgis_bench --iterations 20 --width 1024 --height 768 bench-full.qgs iterations: 20 total_avg: 0.4246 total_max: 0.657 total_maxdev: 0.2324 total_min: 0.407 total_stdev: 0.0535176606364665 *Simplified* ./output/bin/qgis_bench --iterations 20 --width 1024 --height 768 bench-simplified.qgs iterations: 20 total_avg: 0.09615 total_max: 0.098 total_maxdev: 0.001849998 total_min: 0.095 total_stdev: 0.000792148975887722 0.42 / 0.09 is more than 400% performance improvement for this simple case. The results of course depend heavily on the particular setting, but I think this looks indeed like a road we should have a look into. (Setup: PostGIS 2.0.3 in a kvm virtual machine on the same physical machine. No styling at all took place on the layer) Matthias Andreas Am 12.09.2013 07:57, schrieb aperi2007: Not always is preferrable to suppress the small features. Often in our rendering we prefere to substitute a small rendering of kind polygon with a point rendering at lowest scales. This is possible using the Rule-Rendering also is possible to use the rule-rendering to define a rule that in a scale interval and with a dimension interval the feature is render using a point rendering and change in a polygon rendering when the scale grow. Andrea. On 12/09/2013 02:13, Nyall Dawson wrote: Hi all, I've been chatting with Nathan about adding a feature to QGIS which would allow suppression of rendering features smaller than a set threshold for vector layers. (There's already a similar function in the labelling engine Suppress labeling of features smaller than). This feature would come in handy for me for several tables which contain a wide range of very small - very large features, which cause slow rendering at small scales. I'm just checking that if I code this up it's not going to be duplicated effort - Nathan is under the impression that someone else has been talking about adding something similar. Is there currently any plans for a feature like this, or should I get started? Nyall ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] Suppress rendering of small features
This is possible using the Rule-Rendering also is possible to use the rule-rendering to define a rule that in a scale interval and with a dimension interval the feature is render using a point rendering and change in a polygon rendering when the scale grow. While it is possible to set up rules to achieve a similar result, it's quite a lot of work. It's also important to note that the feature I propose would mean it's still possible to use graduated or categorized renderers on a layer - again, the end result (scale/sized based filtering together with categorized rendering) would be achievable by creating a bunch of rules, but it would be a lot of work and the end result would be much more rigid As I understand, the feature to suppress small/large features would be optional. Yes - definitely optional and off by default! How would you define small? I guess something can already be done with scale based visibility, but that needs preprocessing of the data and assigning some kind of size class. I'm thinking of using the same method as the Suppress labelling of features smaller than feature from the labelling engine. This gives you a choice of feature size in mm to use as a threshold, and in my experience works quite well. I think it's important to note that hiding small features isn't just about a performance win - it's also useful from a cartographic perspective. My main use case involves a large water body dataset I frequently use, which contains everything from large lakes and inlets to very small dams and reservoirs. I need to have the large features show up at all scales, but I don't want all these smaller features cluttering up my map at small scales. This feature would mean I could easily hide the little lakes from my map at small scales, but they'd show up as I zoom in. Sure, this could all be done by assigning a hierarchy to the features and setting up a bunch of rules in a rule based renderer - but it would be so much quicker and easier to just tick a box and tweak the threshold size to suit. Another interesting thing would be to simplify features when you zoom out. Maybe simplifying would be quicker than rendering thousands of unnecessary vertices. Wasn't there a summer of code project with this goal a few years back? Does anyone know what the outcome of that project was? Nyall ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] Suppress rendering of small features
Hi, I raised similar question about year ago, but instead hiding small features I propose to do simplification. I also implemented some test code and results were pretty good — redraw is quicker in several times. But my code still hacky and not optimal. Also there were GSoC project, but it was not completed. If you interested, I can try to find code. 2013/9/12 Nyall Dawson nyall.daw...@gmail.com: This is possible using the Rule-Rendering also is possible to use the rule-rendering to define a rule that in a scale interval and with a dimension interval the feature is render using a point rendering and change in a polygon rendering when the scale grow. While it is possible to set up rules to achieve a similar result, it's quite a lot of work. It's also important to note that the feature I propose would mean it's still possible to use graduated or categorized renderers on a layer - again, the end result (scale/sized based filtering together with categorized rendering) would be achievable by creating a bunch of rules, but it would be a lot of work and the end result would be much more rigid As I understand, the feature to suppress small/large features would be optional. Yes - definitely optional and off by default! How would you define small? I guess something can already be done with scale based visibility, but that needs preprocessing of the data and assigning some kind of size class. I'm thinking of using the same method as the Suppress labelling of features smaller than feature from the labelling engine. This gives you a choice of feature size in mm to use as a threshold, and in my experience works quite well. I think it's important to note that hiding small features isn't just about a performance win - it's also useful from a cartographic perspective. My main use case involves a large water body dataset I frequently use, which contains everything from large lakes and inlets to very small dams and reservoirs. I need to have the large features show up at all scales, but I don't want all these smaller features cluttering up my map at small scales. This feature would mean I could easily hide the little lakes from my map at small scales, but they'd show up as I zoom in. Sure, this could all be done by assigning a hierarchy to the features and setting up a bunch of rules in a rule based renderer - but it would be so much quicker and easier to just tick a box and tweak the threshold size to suit. Another interesting thing would be to simplify features when you zoom out. Maybe simplifying would be quicker than rendering thousands of unnecessary vertices. Wasn't there a summer of code project with this goal a few years back? Does anyone know what the outcome of that project was? Nyall ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer -- Alexander Bruy ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] Suppress rendering of small features
On Thu, Sep 12, 2013 at 08:51:43AM +0200, Andreas Neumann wrote: Hi, As I understand, the feature to suppress small/large features would be optional. Another interesting thing would be to simplify features when you zoom out. Maybe simplifying would be quicker than rendering thousands of unnecessary vertices. Optionally this could also be outsourced to the database - many databases support simplification on the db level. I don't know if it would really speed up things. One would have to test. I've done this for mapnik and it worked pretty nicely: http://blog.cartodb.com/post/20163722809/speeding-up-tiles-rendering --strk; ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] Suppress rendering of small features
Hi, I did something somewhat similar to solve #4819 in Jully (Identify Features tool is slow with complex/big features) and Matthias asked me to do the same thing for the rubber-band. In polygon contours, points that are less than a pixel apart from the previous point are not drawn. That improved (dramatically) the rendering speed. Vincent On 12/09/2013 13:03, Sandro Santilli wrote: On Thu, Sep 12, 2013 at 08:51:43AM +0200, Andreas Neumann wrote: Hi, As I understand, the feature to suppress small/large features would be optional. Another interesting thing would be to simplify features when you zoom out. Maybe simplifying would be quicker than rendering thousands of unnecessary vertices. Optionally this could also be outsourced to the database - many databases support simplification on the db level. I don't know if it would really speed up things. One would have to test. I've done this for mapnik and it worked pretty nicely: http://blog.cartodb.com/post/20163722809/speeding-up-tiles-rendering --strk; ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
[Qgis-developer] Suppress rendering of small features
Hi all, I've been chatting with Nathan about adding a feature to QGIS which would allow suppression of rendering features smaller than a set threshold for vector layers. (There's already a similar function in the labelling engine Suppress labeling of features smaller than). This feature would come in handy for me for several tables which contain a wide range of very small - very large features, which cause slow rendering at small scales. I'm just checking that if I code this up it's not going to be duplicated effort - Nathan is under the impression that someone else has been talking about adding something similar. Is there currently any plans for a feature like this, or should I get started? Nyall ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
Re: [Qgis-developer] Suppress rendering of small features
Not always is preferrable to suppress the small features. Often in our rendering we prefere to substitute a small rendering of kind polygon with a point rendering at lowest scales. This is possible using the Rule-Rendering also is possible to use the rule-rendering to define a rule that in a scale interval and with a dimension interval the feature is render using a point rendering and change in a polygon rendering when the scale grow. Andrea. On 12/09/2013 02:13, Nyall Dawson wrote: Hi all, I've been chatting with Nathan about adding a feature to QGIS which would allow suppression of rendering features smaller than a set threshold for vector layers. (There's already a similar function in the labelling engine Suppress labeling of features smaller than). This feature would come in handy for me for several tables which contain a wide range of very small - very large features, which cause slow rendering at small scales. I'm just checking that if I code this up it's not going to be duplicated effort - Nathan is under the impression that someone else has been talking about adding something similar. Is there currently any plans for a feature like this, or should I get started? Nyall ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer ___ Qgis-developer mailing list Qgis-developer@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-developer
