def collide(self):
for a in self.actors:
a.collision_prepare()
for i, ai in enumerate(self.actors):
if isinstance(ai, ParticleActor):
ai.collision_self()
for j, aj in enumerate(self.actors):
if isinstance(aj, ParticleActor):
continue
if i == j: continue
info = spatial.Info(ai.spatial_grid, aj.spatial_mesh, i == j)
mask = info.triangle != -1
active = np.flatnonzero(mask) # active vertex idx
if np.any(mask): # and not isinstance(ai, StaticActor):
triangle = info.triangle[active]
bary = info.bary[active]
velocity = aj.velocity[aj.mesh.faces[triangle]]
velocity = np.einsum('vtc,vt->vc', velocity, bary)
relative_velocity = ai.velocity[active] - velocity
friction = 1e-2
stiffness = 1e1
force = info.depth[active][:, None] * info.normal[
active] * stiffness - relative_velocity * friction
assert not np.any(np.isnan(force))
np.add.at(ai.force, active, force)
corners = aj.mesh.faces[triangle]
for i in range(3):
np.add.at(aj.force, corners[:, i],
-bary[:, [i]] * force)
def test_collision():
meshes = [
icosphere(0.5, refinement=3),
icosphere(0.5, [0.95, 0, 0], refinement=3)
]
lengthscale = 0.2
grids = [spatial.Grid3d(m.vertices, lengthscale) for m in meshes]
ctmeshes = [
spatial.Mesh(m.vertices, m.vertex_normals(), m.faces, 0.1, 0)
for m in meshes
]
for i, mi in enumerate(meshes):
for j, mj in enumerate(meshes):
print(i, j)
info = spatial.Info(grids[i], ctmeshes[j], i == j)
mask = info.triangle != -1
print(info.triangle[mask])
print(info.depth[mask])
