Previz (Previsualization, Animatic) — draft rough CG animations (usually 3D), which is created to plan and handle complex shooting sequences, stunt's and vfx shots.

In immediate past filmmakers used only storyboards, concept art and models for pre-production. With modern previsualization tools creative possibilities increases alot. Now you're able to choose most dramatic camera angles, edit material that isn't yet shooted and add sound effects.

Previz is also cost effective tool, that allowed independent filmmakers and agencies to promote their ideas, find budges and avoid problems on post-production period. Read more (in russian)