To improve the realistic effect of smoke simulation

a real time smoke shadow simulation algorithm based on direct projection and diffusion is proposed. Firstly

the 3D smoke density field is directly projected to a 2D plane and accumulated into a light buffer to generate a texture which describes the shadow energy. Then

diffusion is used as a novel energy spread scheme to deal with the shadow excessive accumulation induced by direct projection. Finally

the shadow texture is mapped to a corresponding surface in 3D scene by projective texture based on programmable graphics hardware. Experiment results show that the algorithm is efficient

simple and effective to achieve real time smoke shadow for 3D computer games and animation.