the performance is mostly unchanged during different weather conditions. When it starts raining the shaders gets a tad heavier, but that shouldn’t be much of an issue. The amount of tree bending has no effect on the performance. It’s only a matter of the stiffness of that particular tree type and the wind velocity. As it is now, the wind speed spans between 0 and about 16m/s. We’re in the middle of Europe in a country surrounded by mountains, on the other hand the turn of the 14. and 15. century was supposed to have pretty crazy weather, so I might make it a bit more extreme.