[Flightgear-devel] Project dynamics (was: Earthview - Orbital terrain rendering in FG)
You haven't really looked at any of my designs so far, have you? Nice trick - didn't work Martin, I have no clue what the point of this is. I'm in the habit of trying to say what I think as clearly as possible, rather than trying to play tricks (I've been hanging around in international communities long enough to know that cross-culture tricks, hints, irony,... as a rule don't work). Flightgear is OpenSource and based on volunteer effort, which means there is no way to tell a contributor to behave a certain way. This basic fact has consequences. We often don't know up front the one and only solution to solve a problem, so it's not just coding the known solution, it's finding the approach which works best for the problem at hand. This fact has other consequences. One of the consequences is that we need to self-organize - there is no supervisor which can tell us what to work on. Self-organization works pretty much as in what I do for a living (research): There is a problem you'd like to solve, but it's too much to do on your own. There are people who have some of the experience or resources needed to solve it. There are others who might get interested and their help might be beneficial. So you start talking, get the people with special expertise interested, you create a proof of concept, they start seeing something might come out of it, they get involved. When the approach is sound, you let the information spread, more people get involved from unexpected sides and the project is well on the way. It's actually considered a good thing if an alternative approach is around - because then there's competition, you may figure out that a different way to do something is way faster, or has other advantages. You can later decide to abandon one approach, or to merge them and take best of two worlds, or to keep both. There are some key factors involved here. First, others have to know what you're doing. You can't expect a project to attract people when you post a description on the wiki and then disappear to code for two years. No human attention span works that way. Once people get involved, they have to see some return on their investment of their time a relatively short timescale. I'm guessing here, but I suspect part of why Stuart or Torsten have been consistently willing to add features to the core which I requested is that I could make a plausible case what these features will do beforehand and that there were results a few weeks later. I don't suppose I could expect much help if I would request something and then disappear for two years without any note. Others have to see the evolving thing, so that they can decide better where to put their efforts (join the existing project, start a conpeting project, do something else). The better they judge your ongoing efforts, the less likely it becomes that they will start competition. In my view, due to the need to self-organize, we can't have as clean and well-organized a project as any commercial enterprise can. There will always be dead ends, the need to go back and remove hacks upon hacks and so on. We can make this easier by writing modular design, but to try to avoid this takes away any advantage our system has, i.e. that it is flexible and can find new and unexpected solutions. There is no point in trying to adopt a commercial development strategy, because we really have none of their advantages, we just throw away ours. I had to rewrite a big chunk of Advanced Weather in the transition to Stuart's cloud rendering system. If we had planned this up-front properly, none of this would have been necessary. So much work wasted? But wait! The flaw in this argument is that if we had planned this up front, we would have nothing because Stuart would have been entirely reasonable to conclude up front that spending a month to code some individual cloud placement and movement routines requested by a forum newcomer proposing to write a complete integrated weather system is a waste of his time, because nothing will ever come out of it (forum users are remarkably quick to propose redesigned terrain engines and similar things). It needed a working imperfect solution to create the momentum for the project to take off, i.e. to convince others that their efforts are well spent here. I believe you have seen more and more people directing their effort into custom scenery rather than official world scenery for precisely the same reasons turned around. Your conclusion from that seems to be that scenery people are just unusually egoistic. My conclusion is that scenery people are pretty normal and self-organize in a pretty normal way - just your assumption that timescales and information flow are secondary as long as the end result is proper is wrong. I realize I'm probably not going to convince you of anything here. Nevertheless, I believe thinking along these lines might save the odd disappointment. Best
Re: [Flightgear-devel] Earthview - Orbital terrain rendering in FG
You ought to be able to initialize any vehicle at any altitude (up to and even beyond 3000 km). At this time, only the Vostok has control jets, as far as I know. Actually I can not do that. Trying to initialize the ufo at 1.000.000 ft works fine, and so does flying the ufo to the altitude. I've then removed the altitude limit detection from the Vostok model leading to an automatic scenario termination. Trying to initialize Vostok at 1.000.000 ft causes Flightgear not to load properly (it gets stuck and some JSBSim messages never appear), trying to fly up beyond 150 km altitude causes a crash of FG shortly after reaching the red zone. So something is happening with a JSBSim model which isn't happening with the ufo FDM. Cheers, * Thorsten -- This SF email is sponsosred by: Try Windows Azure free for 90 days Click Here http://p.sf.net/sfu/sfd2d-msazure ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Earthview - Orbital terrain rendering in FG
I'm a new guy and I have to chime in on this our team wants to use FG for simulations to orbit because we are actually trying to be the first amateurs to make orbit and we would like to do HIL testing. FG may be our only hope. If there is something I can do to help please direct me. Monroe Team Prometheus Original Message Subject: Re: [Flightgear-devel] Earthview - Orbital terrain rendering in FG From: Renk Thorsten thorsten.i.r...@jyu.fi Date: Mon, March 19, 2012 6:22 am To: FlightGear developers discussions flightgear-devel@lists.sourceforge.net You ought to be able to initialize any vehicle at any altitude (up to and even beyond 3000 km). At this time, only the Vostok has control jets, as far as I know. Actually I can not do that. Trying to initialize the ufo at 1.000.000 ft works fine, and so does flying the ufo to the altitude. I've then removed the altitude limit detection from the Vostok model leading to an automatic scenario termination. Trying to initialize Vostok at 1.000.000 ft causes Flightgear not to load properly (it gets stuck and some JSBSim messages never appear), trying to fly up beyond 150 km altitude causes a crash of FG shortly after reaching the red zone. So something is happening with a JSBSim model which isn't happening with the ufo FDM. Cheers, * Thorsten -- This SF email is sponsosred by: Try Windows Azure free for 90 days Click Here http://p.sf.net/sfu/sfd2d-msazure ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel -- This SF email is sponsosred by: Try Windows Azure free for 90 days Click Here http://p.sf.net/sfu/sfd2d-msazure ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Earthview - Orbital terrain rendering in FG
On Monday 19 March 2012 07:22:52 Renk Thorsten wrote: You ought to be able to initialize any vehicle at any altitude (up to and even beyond 3000 km). At this time, only the Vostok has control jets, as far as I know. Actually I can not do that. Trying to initialize the ufo at 1.000.000 ft works fine, and so does flying the ufo to the altitude. I've then removed the altitude limit detection from the Vostok model leading to an automatic scenario termination. Trying to initialize Vostok at 1.000.000 ft causes Flightgear not to load properly (it gets stuck and some JSBSim messages never appear), trying to fly up beyond 150 km altitude causes a crash of FG shortly after reaching the red zone. So something is happening with a JSBSim model which isn't happening with the ufo FDM. Cheers, * Thorsten I assume you ran into a bunch of PT_vs_hpt: ran out of layers for h= messages. This is from FlightGear's rather brittle atmosphere model. The attached patch adds a deep-space layer out to 1e9 meters. I just arbitrarily set the pressure to near 0 and the temperature to damn cold. This patch let me initialize a random JSBSim model at a million feet, however there were still some NaNs present in the property tree when I made it back to sea-level. Ron I sent this half an hour ago, and sourceforge ate it. I'll send it again to see if this one comes through in a timely fashion... diff --git a/src/Environment/atmosphere.cxx b/src/Environment/atmosphere.cxx index 022ea54..f16005f 100644 --- a/src/Environment/atmosphere.cxx +++ b/src/Environment/atmosphere.cxx @@ -18,7 +18,8 @@ ISA_layer(3, 32000, 104986, 868.019,0.256326, 228.65, -44.50, -0.0028, - ISA_layer(4, 47000, 154199, 110.906, 0.0327506, 270.65, -2.50, 0, 0), ISA_layer(5, 51000, 167322, 66.9389, 0.0197670, 270.65, -2.50, 0.0028, 0.0008534), ISA_layer(6, 71000, 232939, 3.95642, 0.00116833, 214.65, -58.50, 0.0020, 0.0006096), -ISA_layer(7, 8, 262467, 0.88628, 0.000261718, 196.65, -76.50), +ISA_layer(7, 8, 262467, 0.88628, 0.000261718, 196.65, -76.50, 0.0, 0.0), +ISA_layer(8, 1.0e9, 3.28e9, 0.1, 3.0e-9,2.73, -270.4, 0.0, 0.0), }; const int ISA_def_size(sizeof(ISA_def) / sizeof(ISA_layer)); -- This SF email is sponsosred by: Try Windows Azure free for 90 days Click Here http://p.sf.net/sfu/sfd2d-msazure___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
