Use these tools to scale the entire scene.
The scale dialogs are accessed via the “Tools” pulldown menu. Use these dialogs to scale the entire scene. The type of scaling done by these utilities is different than using Size scalar properties on the tree model.
These scales affect everything in the scene including wind properties, force locations, force sizes, collision objects, and all other properties that may affect the tree's shape during scale operations. Use either of these utilities to make the entire tree bigger or smaller without changing shape.
Use this tool to scale the scene by any arbitrary value. Access it via “Tools→Arbitrary scene scale…”.
Use this tool to convert the scene from one unit system to another. Access it via “Tools→Scene unit conversion…”. Most SpeedTree library models are modeled in feet so to convert one of them choose “Feet” as the “Convert from” option and then select the desired unit system as the “to” option.