//The main fluid simulation step
void FluidSim::advance(float dt) {
float t = 0;
while(t < dt) {
float substep = cfl();
if(t + substep > dt)
substep = dt - t;
//Passively advect particles
advect_particles(substep);
//Estimate the liquid signed distance
compute_phi();
//Advance the velocity
advect(substep);
add_force(substep);
apply_viscosity(substep);
apply_projection(substep);
//Pressure projection only produces valid velocities in faces with non-zero associated face area.
//Because the advection step may interpolate from these invalid faces,
//we must extrapolate velocities from the fluid domain into these zero-area faces.
extrapolate(u, u_valid);
extrapolate(v, v_valid);
//For extrapolated velocities, replace the normal component with
//that of the object.
constrain_velocity();
t+=substep;
}
}
//The main fluid simulation step
void FluidSim::advance(float dt) {
//Passively advect particles
advect_particles(dt);
//Advance the velocity
advect(dt);
add_force(dt);
project(dt);
//Pressure projection only produces valid velocities in faces with non-zero associated face area.
//Because the advection step may interpolate from these invalid faces,
//we must extrapolate velocities from the fluid domain into these zero-area faces.
extrapolate(u, u_weights, valid, old_valid);
extrapolate(v, v_weights, valid, old_valid);
//For extrapolated velocities, replace the normal component with
//that of the object.
constrain_velocity();
}
//The main fluid simulation step
void FluidSim::advance(float dt) {
float t = 0;
while(t < dt) {
float substep = cfl();
if(t + substep > dt)
substep = dt - t;
printf("Taking substep of size %f (to %0.3f%% of the frame)\n", substep, 100 * (t+substep)/dt);
printf(" Surface (particle) advection\n");
advect_particles(substep);
printf(" Velocity advection\n");
//Advance the velocity
advect(substep);
add_force(substep);
printf(" Solve viscosity");
apply_viscosity(substep);
printf(" Pressure projection\n");
project(substep);
//Pressure projection only produces valid velocities in faces with non-zero associated face area.
//Because the advection step may interpolate from these invalid faces,
//we must extrapolate velocities from the fluid domain into these invalid faces.
printf(" Extrapolation\n");
extrapolate(u, u_valid);
extrapolate(v, v_valid);
extrapolate(w, w_valid);
//For extrapolated velocities, replace the normal component with
//that of the object.
printf(" Constrain boundary velocities\n");
constrain_velocity();
t+=substep;
}
}
