def initialize_particle_grid():
for p in range(num_particles[None]):
x = particle_x[p]
v = particle_v[p]
ipos = ti.floor(x * particle_grid_res).cast(ti.i32)
for i in range(-support, support + 1):
for j in range(-support, support + 1):
for k in range(-support, support + 1):
offset = ti.Vector([i, j, k])
box_ipos = ipos + offset
if inside_particle_grid(box_ipos):
box_min = box_ipos * (1 / particle_grid_res)
box_max = (box_ipos + ti.Vector([1, 1, 1])) * (
1 / particle_grid_res)
if sphere_aabb_intersect_motion(
box_min, box_max, x - 0.5 * shutter_time * v,
x + 0.5 * shutter_time * v, sphere_radius):
ti.append(pid.parent(), box_ipos, p)
voxel_has_particle[box_ipos] = 1
def initialize_particle_grid(self):
for p in range(self.num_particles[None]):
v = self.particle_v[p]
x = self.particle_x[p]
ipos = ti.floor(x * self.inv_dx).cast(ti.i32)
offset_begin = shutter_begin * self.shutter_time * v
offset_end = (shutter_begin + 1.0) * self.shutter_time * v
offset_begin_grid = offset_begin
offset_end_grid = offset_end
for k in ti.static(range(3)):
if offset_end_grid[k] < offset_begin_grid[k]:
t = offset_end_grid[k]
offset_end_grid[k] = offset_begin_grid[k]
offset_begin_grid[k] = t
offset_begin_grid = int(ti.floor(
offset_begin_grid * self.inv_dx)) - 1
offset_end_grid = int(ti.ceil(offset_end_grid * self.inv_dx)) + 2
for i in range(offset_begin_grid[0], offset_end_grid[0]):
for j in range(offset_begin_grid[1], offset_end_grid[1]):
for k in range(offset_begin_grid[2], offset_end_grid[2]):
offset = ti.Vector([i, j, k])
box_ipos = ipos + offset
if self.inside_particle_grid(box_ipos):
box_min = box_ipos * self.dx
box_max = (box_ipos +
ti.Vector([1, 1, 1])) * self.dx
if sphere_aabb_intersect_motion(
box_min, box_max, x + offset_begin,
x + offset_end, self.sphere_radius):
ti.append(
self.pid.parent(), box_ipos -
ti.Vector(self.particle_grid_offset), p)
self.voxel_has_particle[box_ipos] = 1
self.voxel_grid_density[box_ipos] = 1