$treesway
$treesway - это параметр шейдера материала , доступный во всех играх на Template:Game name, начиная с Template:Game name для VertexLitGeneric. Это так же доступно в 
. В , это можно использовать и для UnlitGeneric.
$treesway morphs a material around using the parameters of an env_wind entity to give the appearance of tree leaves and foilage blowing in the wind. The subparameters of $treesway determine how much the env_wind entity should affect the morphing, and all of them (except $treeswaystatic) must be specified in order for the effect to work properly. This shader parameter assumes any model using it is facing upwards.
Предупреждение:Due to the way bumped lighting is calculated, $treesway will not sway materials which use $bumpmap.
Примечание:This shader parameter is disabled by default in the 
SDK. It can re-enabled by modding.
Баг:In , using a shadow-casting projected texture on materials with this parameter will cause flickering. As a workaround, try to keep trees away from where player flashlights can reach. $halflambert may also partially fix the issue. [нужно проверить в ?]Параметры
$treesway
$treeswayheight
$treeswaystartheight
$treeswayradius
$treeswaystartradius
$treeswayspeed
$treeswaystrength
$treeswayscrumblespeed
$treeswayscrumblestrength
$treeswayscrumblefrequency
$treeswayfalloffexp
$treeswayscrumblefalloffexp
$treeswayspeedhighwindmultipler
$treeswayspeedlerpstart
$treeswayspeedlerpend
$treeswaystatic
$treeswaystaticvalues
Смотрите так же
https://gamebanana.com/tuts/12924 - Как достигнуть похожий эффект без $treeSway, во всех source engine играх.