RealFlow SD Importer (SI)
RealFlow is not only a powerful fluid simulation tool, but also provides a fully-featured rigid and soft body dynamics solver. Furthermore, you can choose from several built-in primitives, like sphere, torus, or cube. With the help of the “RealFlow SD Exporter” plugin or the Alembic file format it is also possible to use objects from Cinema 4D inside RealFlow. There, the objects can be fractured, or turned into soft and rigid bodies. All these transformations are cached, and the “RealFlow Importer Plugin” is able to read this information. In Cinema 4D the imported objects are textured, combined with other elements – for example fluids – and finally rendered.
The “SD” abbreviation in the plugin's name stands for “Scene Data” and describes a proprietary RealFlow format for geometric data. It can store motion, rotation, scale, and UV data, as well as Cinema 4D's PLA (“Point Level Animation”) information. Deformations from soft bodies are also supported. In SD files, all polygons must be triangulated. The SD format has a rather simple structure, and therefore a Cinema 4D's hierarchy and groups are considered. Naming is another important point with SD files, because it does not allow the usage of special characters. The dot character should be avoided, too, because it has a certain meaning for RealFlow's Python interface.
RealFlow writes the simulation data of a scene's objects to one file. Depending on the number and complexity of the objects, this file can become very large. It is also possible to write SD files for each object individually. If you want to learn how to do this please follow this link (look for "Animation (.sd)").