These are the major improvements:

Image size for rendering increased to 128k x 128k pixels (64-bit only)
Image size for textures increased to 128k x 128k pixels (64-bit only)
Alpha-mapped objects now supported in Multi-Pass Depth, UVW and Normal channel
Axis Gizmo now properly supports world orientation
Support of Photoshop Big file format (PSB)
Preference Settings re-introduced (ctrl+click on Mac, Insert At, Paste At, Create New Object in View Center)
Output Color Profile can be chosen for Bake Texture
Improved Missing Textures dialog
Camera shader now supports film offset
Additional Python methods (CAPoseMorphTag, GetRelMin)
Vectorworks 2011 Support

Additionally, over 130 problems were fixed since R12.021. The primary corrections are:

Overall stability
Character animation tools (weighting, dynamic IK, stick mode)
Dynamics (caching, soft body behavior)
File exchange (FBX, VRML2)
Materials (faster preview rendering, wrong frame handling in animated textures, camera shader aspect ratio, Frensel shader in Specularity channel fixed)
Modeling (Join Segment, Correction Deformer, memory leak fixed, Connect function fixed)
MoGraph (Shader Effector, Axis Tool in MoText, orientation problems fixed)
OpenGL (stacked materials, transparency, anisotropic, alpha display, ghosting with colors, texture flickering, screen redraw, clipping with skies, tinted poly selection, fresnel, interactive render region with PyroCluster)
Python (improved stability, behavior of various functions corrected)
Renderer (Render Queue, HDR Probe conversion, color temperature, motion vectors, straight alphas with LWF)
And more… (Animation and Timeline, Online Updater, Modeling tools, Preferences)

This update also includes the improvements from 12.016 to 12.021 which are:

FBX and COLLADA import and export
PoseMorph
Weighting tools
Behavior of various Deformers
Dynamics
Python
Turtle Mode / L-System
OpenGL
Vector Motion Blur
Renderer

“This is a Xpresso-Setup I made for Characteranimation. It can be used to let a walkcycle move on a Spline without foots sliding on the floor.” -Holger Biebrach

LINK

Pariah Studios: In this quick tutorial you will learn how to set vertex weights in cinema 4D and how they can be used tocontrol dynamic simulations.

C4D Vertex weights & dynamics in R12 from rob redman on Vimeo.

Project files and more tutorials at Pariah Studios.