On Sunday, August 26, 2012 21:04:53 Clement de l'Hamaide wrote: > I have done some test. Here is the result : > > Nb of object Without _AGL With _AGL > 0 20.4s > 20.4s 500 21.4s > 21.4s 5 000 21.6s > 23.4s 15 000 24.0s > 29.9s 30 000 27.2s > 39.1s 100 000 52.1s > 95.6s > > For information, TerraSync has 1 100 000 thus when I try to load 15 000 > object I tried to load 1% of the entire TerraSync database in at once. And > with 100 000 it's 10% of the entire TerraSync database. Of course it's not > realist since objects are placed everywhere in the world in this way 1 STG > file can't contains 1% of the entire TerraSync database. > > For example if the whole LOWI region (less than 4000 objects) was > transformed with _AGL the loading time will increase of less than 2 > seconds. As LOWI is one of the most advanced scenery it's a good > comparison. > > With these test I can conclude that the _AGL tag can increase the loading > time (and it's normal) but it's insignificant because FG doesn't load more > than 5000 objects at once since tiles are loaded step by step.
That's what I was trying to say to you. It might be the case that you do not see a huge problem today, but given you will see some changes in future scenery this will come up. To me, for that argument I just no not care at all what todays scenery just do by accident. Where accident I mean in this particular case that we have currently few triangles in the scene - which is good for many reasons including the one you are talking about. But it's clear to me that it's just a matter of time until we have something more finegrained. Then this will be more of an issue. Really, think about how such an algorithm works that you need to implement this feature, what computational compexity is sitting behind this and under which curcumstances this hurts. So not to be harsh, but to really judge about if this will be a problem or not I expect you to understand the above *in* *detail*. Then once you understood that, think about what is probably happeing next to the scenery. Then think about how people typically act in this kind of projects and see how the probability is that we will in the not so far future get scenery where it will be way more of a problem. How these claims all affect each other is left as an exercise ... Also you will find that today convenient to give agl numbers. But Trust me, there are plenty of people out there who do not care at all about your convenience. They want the scenery and they think about why this is taking longer when you use this feature widely. And the only answer is in the end: for no sensible reason - we can equally well precompute these elevations. And given your numbers I am surprised very bad how huge the impact already is with the current scenery. If you personally want to wait longer - I personally don't care. But please, in any officially published scenery, do *not* use this agl numbers and instead precompute the elevations! Thanks for reporting that it works so far. Mathias ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
