Method for modeling complex occlusions in fluid simulations

In a method of fluid simulation where state of a fluid comprising of velocities is updated in the presence of impermeable objects having surfaces in a given region over discrete time steps by:

• dividing the region into cells comprising a regular grid and then defining a velocity field which associated a velocity vector with each cell;
• and
• recalculating the velocity field at each consecutive time step based on the state of the fluid on the previous time step and the effect of impermeable object surfaces via Navier-Stokes equations comprising calculation of advection and pressure effects;
• the improvement comprising:
• assigning a value to the velocity vectors, associated with the cells contained within the impermeable objects when the velocity field is used for the calculation of the advection and pressure effects, which is copied from the closest fluid containing cell;
• and
• when the value includes a normal component which would cause motion of the fluid into the object, removing the normal component.