Thorsten > > This scheme introduces yet another for loop in Nasal, of undetermined > > size. This potentially introduces yet another source of stagger to FG, > > or it would if it worked, but as far as I can see it never runs here. Is it > meant?
> Well, anticipating your reaction, yes, at this point it's meant not to run by > default. It is an experimental feature which you get to see only when running > Advanced Weather and lightfield shaders - meant as a proof of concept, > borrowing the load-by-default structure of Advanced Weather. I wouldn't > dream of sneaking any Nasal loop running by default into FGData, I know > very well how that would be received. If the idea catches, I will bother to give > it a separate on-demand control structure. Hmm I've got something wrong here then - if I understand that right I select Advanced Weather, and skydome and the sea colour stuff should run? I get this: http://dl.dropbox.com/u/57645542/fgfs-screen-190.png It doesn't seem to have any interpolation. > Having said that, your argument about performance is actually rather far > fetched. > > The loop runs every 5 seconds (!), in each loop iteration it updates the > distance table for one single interpolation point (i.e. the loop performance > consumption doesn't really increase even if you have 1000 interpolation > points in there because I'm not doing 1000 distances per iteration, I'm doing > one), so I seriously doubt you will ever be able to measure the performance > footprint of the thing even if you try really hard. So, I don't think there's a > good case against this apart from general dislike of Nasal solutions. > I was thinking of this for loop for (var i = 0; i < ivector_size; i = i + 1) I take the view that any for loop is not good, but if ivector_size is small, I guess it won't matter. I put a print statement inside this loop - and so far I've not seen it run. I also put print statements in the sea_color_loop, and one in init_sea_colors, but they don't run either. I'm definitely missing something here. > > Nevertheless, perhaps it has promise in introducing muddy water. > > It's an interpolation system. The output depends on the input - how to > determine reasonable input is quite a different matter. My take on that is > that, for whatever reason, I never got the impression that the North Sea > ever looked like the Mediterrainean to me. So there is more to water color > than just the reflected sky. In any case, having the possibility to change > things runtime seems perferable to me over not having it. There are good sources for sea colour out there - here is one: http://oceancolor.gsfc.nasa.gov/FEATURE/IMAGES/A2008129125500.Scotland.png The Northern North Sea, away from the turbidity and major river outfalls of the Southern North Sea, is indistinguishable from the Atlantic, the other side of Scotland. There are many examples in this archive, and if there are differences in the deep ocean colour in any of the oceans they are darned hard to spot. Similarly, if there is a difference between the Atlantic and the Mediterranean, it's very hard to see. > The scheme is certainly not completely realistic and also a bit simplistic - but > it's more realistic than a constant water color everywhere, and it is so at the > expense of one distance computation every 5 seconds (and sums which > don't really count because basic arithmetics is dead-cheap to do). Whilst variations in the blue of the deep oceans is arguably not worth the effort, there are many regions where the deep ocean blue is not appropriate - the outflows of major rivers, the turbid shallower seas and so forth We can do muddy. Phytoplankton blooms! To difficult! Hope I can make this work soon Vivian ------------------------------------------------------------------------------ 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
