#2099 Precipitation: visual lagging behind "physical" value, apparent wind on intensity change. (patch available)

During the precipitation intensity fade, the wall of effects appears to move as if the wind was a lot faster than normal when the intensity is increasing and a lot slower or even to the opposite side if it's decreasing. I remember seeing this all the time since a long ago, so it must be an old bug.

How to reproduce: Environment/Weather/Manual Configuration, move the Rain or Snow slider.

[legoboyvdlp]

@mike402 Do you mean the ALS glass effect? I see that the raindrops rendered on glass start moving quickly as you move the slider; however I don't see the actual precipitation things going crazy while dragging the slider.

This is just sitting on the runway.

What I do see is that when I move the slider the precipitation is vertical; after some time it then rotates to match the active wind.

And sometimes it even flickers between vertical and rotated.

[Anonymous]

No, I mean rain or snow texture (particles) in the air. It looks like it being zoomed or something else is making it look like there's additional wind.

But change in raindrops ALS effect might actually suggest there's an issue not with precipitation, but something deeper?

[Anonymous]

This is likely caused by the repetition of the same pattern between different layers of precipitaiton, forming tunnels of lines:

https://github.com/openscenegraph/OpenSceneGraph/issues/1080

[Anonymous]

I found out that the interpolation built into precipitation.cxx makes this effect more pronounced, while the weather system already seems to interpolate the precipitation intensity on its own.

This delay also makes the visual rain/snow intensity lag behind the "real" values in /environment/{rain,snow}-norm that could be used by aircraft systems, for example the raindrop effect of ALS Glass (such as in c172p) appears ahead of the actual rain. Would it be ok to remove the interpolation?