Anyways all wrong threads, one problem I see (and I don't want to start a new one) is the transitions in all weather states, affecting the shader effects like clouds and water most noticeably, when the METAR system updates the weater in FG the thansition should be smooth and not some drastic weather change, it makes it unreal (clouds popping up/dissapearing and sea waves moving fast).
Are we talking Advanced Weather here? Because I haven't ever observed METAR updates there, there are about 100 lines of code written to the express purpose of hiding them from the user.
A METAR update doesn't do anything to advance weather until the next tile is built, then it creates a weather parameter vector for interpolation and builds a tile according to cloud cover info. There are two issues here:
* a you can see a tile being built, i.e. clouds 'popping up'
-> that's currently unavoidable for large cloud visibility distances, because in order to do cloud-terrain interaction you need to know the terrain, in order to know the terrain you need to have it loaded and the range out to which it is loaded is given by the visibility, so unless someone separates the distance at which terrain is loaded from visibility, that is how it has to be. But it hasn't got anything to do with METAR. If you select the visibility distance of clouds small enough, you can hide the appearance of clouds.
* wind (pressure, temperature...) change after a METAR update
-> new interpolation vectors are faded in with a weight of 0.01, increasing each loop iteration by 0.01. The timer for loop iteration is 0.2 sec, so effectively it takes 20 seconds for the interpolation point to be fully recognized. But even then, you're not seeing 100% of its effect, you're seeing the 1/d weighted average with all other interpolation points present. I've actually taken the pains when I designed the system to write out curves of all weather parameters during a 10 minute flight with the ufo probing a few weather stations and plot them later on to verify there are no discontinuities being created, all parameters change very smoothly. If you think otherwise, repeat the exercise and show me the plot... In other words, as far as I am concerned, there is no issue of sudden changes of any weather parameter.
The problem with the water shader is that it can't deal with smooth transitions too well. But in reality, there are really fast wind changes, like in gusts the wind can change by 10 kt within a few seconds easily, so one cannot assume that wind changes slowly. But that's unrelated to the weather system.