Before the SpeedTree Clarisse plugin was developed, the best way to get SpeedTree geometry into Clarisse was by exporting a large mesh out of SpeedTree Cinema. If you wanted wind or growth animation, you'd have to export enormous point caches that were baked with fixed parameters. With the Clarisse plugin, you'll be able to load compact procedural files (~1 MB) and generate a tree's geometry in Clarisse with resolution, season, and wind & growth animation settings adjusted on the fly.
There are two new object types added to Clarisse:
The SpeedTree:Model object reads SpeedTree STE and SPM files. These are the files primarily read and written by SpeedTree Cinema. The official SpeedTree Tree Library also use this format.
Materials, as defined in SpeedTree Cinema, are also imported into Clarisse, detailed here.
Because SpeedTree is procedural, there are several things that can be controlled interactively in Clarisse. These include: