[Blender x Python] Particle Animation (Part 1)

table of contents

0. Draw a straight line
1. Draw a spiral (Part 1)
2. Draw a spiral (Part 2)
3. Draw a tornado
4. Change instance
5. Random walk

0. Draw a straight line

import bpy
import math as m

#Determine the final frame
end_frame = 100

#Create a function for particles
def particle_road(p_count = 50000,p_end = end_frame,p_lifetime = end_frame,p_normal_factor = 0,p_gravity = 0):   
    #Add a particle system
    bpy.ops.object.particle_system_add()

    #Make various settings
    p_s = bpy.context.active_object.particle_systems[0].settings
    #Total number of particles
    p_s.count = p_count
    #Particle end frame
    p_s.frame_end = p_end
    #Particle duration
    p_s.lifetime = p_lifetime
    #Particle velocity
    p_s.normal_factor = p_normal_factor
    #Gravity on particles
    p_s.effector_weights.gravity = p_gravity
    

#Add an emitter
bpy.ops.mesh.primitive_cube_add()
obj = bpy.data.objects["Cube"]

frame_num = 0
bpy.context.scene.frame_end = end_frame
x = 0
y = 0

for i in range(0,end_frame):
    bpy.context.scene.frame_set(frame_num)
    x += 1
    y += 1
    obj.location = (x,y,0)
    obj.keyframe_insert(data_path = "location",index = -1)
    frame_num += 1

#Use the defined function
particle_road()

0. Draw a spiral

import bpy
import math as m

end_frame = 300

def particle_road(p_count = 50000,p_end = end_frame,p_lifetime = end_frame,p_normal_factor = 0,p_gravity = 0): 

    bpy.ops.object.particle_system_add()

    p_s = bpy.context.active_object.particle_systems[0].settings
    p_s.count = p_count
    p_s.frame_end = p_end
    p_s.lifetime = p_lifetime
    p_s.normal_factor = p_normal_factor
    p_s.effector_weights.gravity = p_gravity
    

bpy.ops.mesh.primitive_cube_add()
obj = bpy.data.objects["Cube"]

frame_num = 0
bpy.context.scene.frame_end = end_frame
#Radius of spiral
r = 30
#How to divide the circumference into equal parts
detail = 24

for i in range(0,end_frame):
    rad = 2 * m.pi * i/detail
    x = m.cos(rad) * r
    y = m.sin(rad) * r
    z = i/2
    
    bpy.context.scene.frame_set(frame_num)
    obj.location = (x,y,z)
    obj.keyframe_insert(data_path = "location",index = -1)
    frame_num += 1
    
particle_road()

2 spiral (Part 2)

import bpy
import math as m

end_frame = 700

def particle_road(p_count = 300000,p_end = end_frame,p_lifetime = end_frame,p_normal_factor = 0,p_gravity = 0):   
    
    bpy.ops.object.particle_system_add()

    p_s = bpy.context.active_object.particle_systems[0].settings
    p_s.count = p_count
    p_s.frame_end = p_end
    p_s.lifetime = p_lifetime
    p_s.normal_factor = p_normal_factor
    p_s.effector_weights.gravity = p_gravity
    

bpy.ops.mesh.primitive_uv_sphere_add()
obj = bpy.data.objects["Sphere"]

frame_num = 0
bpy.context.scene.frame_end = end_frame
#Radius of spiral
r = 1
z = 0
z_speed = 3
detail = 24

for i in range(0,end_frame):
    rad = 2 * m.pi * i/detail
    x = m.cos(rad) * r
    y = m.sin(rad) * r
    z += z_speed
    
    if(z > 100 or z < 0):
        #Reverse the direction of z
        z_speed *= -1
        #Expand the radius
        r += 10
    
    bpy.context.scene.frame_set(frame_num)
    obj.location = (x,y,z)
    obj.keyframe_insert(data_path = "location",index = -1)
    frame_num += 1
    
particle_road()

3. Draw a tornado

import bpy
import math as m

end_frame = 700

def particle_road(p_count = 50000,p_end = end_frame,p_lifetime = end_frame,p_normal_factor = 0,p_gravity = 0):   
    bpy.ops.object.particle_system_add()

    p_s = bpy.context.active_object.particle_systems[0].settings

    p_s.count = p_count
    p_s.frame_end = p_end
    p_s.lifetime = p_lifetime
    p_s.normal_factor = p_normal_factor
    p_s.effector_weights.gravity = p_gravity
    

bpy.ops.mesh.primitive_uv_sphere_add()
obj = bpy.data.objects["Sphere"]

frame_num = 0
bpy.context.scene.frame_end = end_frame 
r = 10
z = 0
z_speed = 3
detail = 24

for i in range(0,end_frame):
    rad = 2 * m.pi * i/detail
    x = (r * i)/30 *  m.cos(rad)
    y = (r * i)/30 *  m.sin(rad)
    z = i
    
    bpy.context.scene.frame_set(frame_num)
    obj.location = (x,y,z)
    obj.keyframe_insert(data_path = "location",index = -1)
    frame_num += 1
    
particle_road()

4. Change the instance

import bpy
import math as m

end_frame = 500
bpy.ops.mesh.primitive_cube_add()


def particle_road(p_count = 500,p_end = end_frame,p_lifetime = end_frame,p_normal_factor = 0,p_gravity = 0):   
    
    bpy.ops.object.particle_system_add()
    p_s = bpy.context.active_object.particle_systems[0].settings

    p_s.count = p_count
    p_s.frame_end = p_end
    p_s.lifetime = p_lifetime
    p_s.normal_factor = p_normal_factor
    p_s.effector_weights.gravity = p_gravity
    #Instantiate an object
    p_s.render_type = 'OBJECT'
    #Instantiate Cube
    p_s.instance_object = bpy.data.objects["Cube"]
    #Determine the size
    p_s.particle_size = 10
    #How to adapt random to size
    p_s.size_random = 1

bpy.ops.mesh.primitive_uv_sphere_add()
obj = bpy.data.objects["Sphere"]

frame_num = 0
bpy.context.scene.frame_end = end_frame
r = 70
detail = 24

for i in range(0,end_frame):
    rad = 2 * m.pi * i/detail
    x = m.cos(rad) * r
    y = m.sin(rad) * r
    z = i * 3
    
    bpy.context.scene.frame_set(frame_num)
    obj.location = (x,y,z)
    obj.keyframe_insert(data_path = "location",index = -1)
    frame_num += 1
    
particle_road()

5. Random walker

import bpy
from random import randint

end_frame = 5000

def particle_road(p_count = 500000,p_end = end_frame,p_lifetime = end_frame,p_normal_factor = 0,p_gravity = 0):   
    bpy.ops.object.particle_system_add()

    p_s = bpy.context.active_object.particle_systems[0].settings

    p_s.count = p_count
    p_s.frame_end = p_end
    p_s.lifetime = p_lifetime
    p_s.normal_factor = p_normal_factor
    p_s.effector_weights.gravity = p_gravity
    

bpy.ops.mesh.primitive_cube_add()
obj = bpy.data.objects["Cube"]

frame_num = 0
bpy.context.scene.frame_end = end_frame

x = 0
y = 0
z = 0

for i in range(0,end_frame):
    
    #Randomly select an integer from the range from the first argument to the second argument
    m = randint(-20,20)
    
    #If the number of frames divided by 3 is 0
    if(i%3 == 0):
        x += m
    #If the number of frames divided by 3 is 1
    elif(i%3 == 1):
        y += m
    #Otherwise
    else:
        z += m
    
    bpy.context.scene.frame_set(frame_num)
    obj.location = (x,y,z)
    obj.keyframe_insert(data_path = "location",index = -1)
    frame_num += 1
    
particle_road()