def deviate(branch_angle, branching, twist, initial_phyllotaxic_angle,
plagiotropism_buds, gravitropism_buds, parent_direction, i, j):
direction = parent_direction.normalized()
axis = direction.to_track_quat('X', 'Z') * Vector((0.0, 0.0, 1.0))
deviate_dir = Quaternion(axis, branch_angle) * direction
offset = 0.0
if branching == 1:
offset = 2.4
elif branching == 2:
offset = 1.5708 + twist
elif branching == 3:
offset = 2.4
elif branching == 4:
offset = 0.7854 + twist
elif branching == 5:
offset = 0.6283
elif branching == 6:
offset = 0.5236
phyllotaxis_angle = initial_phyllotaxic_angle + offset * i
phyllotaxis_angle += 6.2832 * j / branching
phyllotaxis_angle %= 6.2832
flat_dir = parent_direction.copy()
flat_dir.z = 0.0
horizontal = 1.0 - (abs(parent_direction.angle(flat_dir, 0.0)) / 1.5708)
if parent_direction.x == 0.0 and parent_direction.y == 0.0:
horizontal = 0.0
plagio = plagiotropism_buds * horizontal
if plagio > 1.0:
plagio = 1.0
if phyllotaxis_angle < 1.5708:
phyllotaxis_angle = (1.0 - plagio) * phyllotaxis_angle
elif phyllotaxis_angle < 4.7124:
phyllotaxis_angle = plagio * 3.1416 + (1.0 -
plagio) * phyllotaxis_angle
else:
phyllotaxis_angle = plagio * 6.2832 + (1.0 -
plagio) * phyllotaxis_angle
deviate_dir = Quaternion(direction, phyllotaxis_angle) * deviate_dir
flat_deviate_dir = deviate_dir.copy()
flat_deviate_dir.z = 0.0
strength = (1.0 - horizontal) * plagiotropism_buds
deviate_dir = deviate_dir.lerp(flat_deviate_dir, strength)
if gravitropism_buds < 0.0:
vector_up = Vector((0.0, 0.0, 1.0))
deviate_dir = deviate_dir.lerp(vector_up, -gravitropism_buds)
else:
vector_down = Vector((0.0, 0.0, -1.0))
deviate_dir = deviate_dir.lerp(vector_down, gravitropism_buds)
return deviate_dir
