Cinema4D Plugins
Cinema4D plugins, to boost your modelling and animation abilities...
Plugins currently available:
fusionThing 1.0 
($195)
A very powerful procedural modelling and animation system that lets you build with meshes rather than with vertices and polygons. Works in two modes - 'Immediate mode' for rapid workflow when you know exactly what you want, and 'Object mode' for when you want maximum flexibility, and for when you need advanced animation. Check the main page for samples, training videos, and full tutorial manual.
spinPoly 2.0 
($10)
A simple to use modelling tool which lets you rapidly change the flow of your meshes by spinning shared edges of adjacent polygons, or spinning all polygons around a single vertex. Can be used on textured models without disturbing existing UVW mappings.
geomCheck 1.1 
FREE!
A handy tool for finding problems in your meshes. It can detect lots of different types of problems with geometry, which can cause shading or subdivision artefacts, and other troubles.