In fast figure animation, motion blur is often employed to generate fantastic effects of figure motion, for exaggerating the atmosphere one wants to convey. In the previous works for long time, the solution based on certain kind of image blending in terms of hardware or software, was simply adopted. In order to provide high standard of motion blur effect, methods based on 3D geometry of the motion figure with global illumination become gradually in demand. However, the computation cost to meet such demand is very high and it is hard to achieve real time rendering. In our work, a novel 3D geometric approach of real-time motion effect is proposed. By the approach, a special effect along the motion trajectory based on fluid simulation is combined with the volumetric motion blur. Besides, in order to avoid the redundant calculation of each frame and break the limitation of trajectory generation, we decompose the motion trajectory and employ multi-pass geometry rendering to achieve geometry instancing for reuse. In the pipeline, we separate motion tracking and fluid solution, to support various fluid effects flexibly. As our algorithm is constructed in the context of GPU geometry shading in parallel, high efficiency of computation is guaranteed while realizing gorgeous rendering. As a result, real time rendering including the motion blur effect is achieved. © 2011 ACM.