# Add the upper directory (where the nodebox module is) to the search path.
import os, sys; sys.path.insert(0, os.path.join("..",".."))
from nodebox.graphics import *
from nodebox.graphics.physics import System, Emitter, Particle, MASS
# 1) An emitter will be firing particles with a constant velocity.
# 2) Drag in the system slows down the particles.
# 3) Gravity then becomes greater than the particles' velocity and they are pulled down.
s = System(gravity=(0, 1.0), drag=0.01)
# The emitter is positioned centrally at the bottom,
# and fires particles upwards in a 30-degrees angle range.
e = Emitter(x=200, y=0, angle=90, strength=10.0, spread=30)
for i in range(100):
# Particles have random mass and lifespan to make it more interesting and diverse.
# The MASS constant means that we want the radius of the visual particle
# to be initialized with the same value as its mass (it's a convenience trick).
# This way we can observe how heavier particles respond.
e.append(Particle(0, 0, mass=random(10,50), radius=MASS, life=random(50,250)))
s.append(e) # Install the emitter in the system.
# Add an obstacle that other particles want to stay away from.
class Obstacle(Particle):
def draw(self):
# The only way to style individual particles is to redefine draw() in a subclass.
# Set the fill color directly for this ellipse, i.e. don't use fill(),
# because this sets the state and then other particles might use this color too.
ellipse(self.x, self.y, self.radius*2, self.radius*2, fill=(0,0,0.3,0.1))
# Add the upper directory (where the nodebox module is) to the search path.
import os, sys
sys.path.insert(0, os.path.join("..", ".."))
from nodebox.graphics import *
from nodebox.graphics.physics import Particle, Force, System
# This example demonstrates the Animation object,
# which can be used to store and replay a sequence of image frames.
# This is useful for caching pre-rendered effects, like a spell or an explosion.
# This is just the explosion system from the previous example in a more condensed form.
s = System(gravity=(0, 1.0))
for i in range(80):
s.append(Particle(x=200, y=250, mass=random(5.0, 10.0), radius=5, life=30))
s.force(strength=4.5, threshold=70)
# Instead of drawing the system directly to the canvas,
# we render each step offscreen as an image,
# and then gather the images in an animation loop.
explosion = Animation(duration=0.75, loop=False)
for i in range(30):
s.update(limit=20)
img = render(s.draw, 400, 400)
explosion.append(img)
# This can take several seconds:
# - calculating forces in the system is costly (if possible, load Psyco to speed them up),
# - rendering each image takes time (specifically, initialising a new empty image).
# If possible, reduce the image frames in size (smaller images = faster rendering).
import os, sys
sys.path.insert(0, os.path.join("..",".."))
from nodebox.graphics.context import *
from nodebox.graphics import *
from nodebox.graphics.physics import Particle, Force, System
from nodebox.graphics.shader import render
# This example demonstrates the Animation object,
# which can be used to store and replay a sequence of image frames.
# This is useful for caching pre-rendered effects, like a spell or an explosion.
# This is just the explosion system from the previous example in a more condensed form.
s = System(gravity=(0, 1.0))
for i in range(80):
s.append(Particle(x=200, y=250, mass=random(5.0,10.0), radius=5, life=30))
s.force(strength=4.5, threshold=70)
# Instead of drawing the system directly to the canvas,
# we render each step offscreen as an image,
# and then gather the images in an animation loop.
explosion = Animation(duration=0.75, loop=False)
for i in range(30):
s.update(limit=20)
img = render(s.draw, 400, 400)
explosion.append(img)
# This can take several seconds:
# - calculating forces in the system is costly (if possible, load Psyco to speed them up),
from nodebox.graphics.context import *
from nodebox.graphics import *
from nodebox.graphics.physics import Particle, Force, System
# BANG!
# Here is a short example of how the Particle class
# can be subclassed with a custom draw() method:
class Spark(Particle):
def draw(self):
r = self.radius * (1-self.age)
ellipse(self.x, self.y, r*2, r*2)
s = System(gravity=(0, 2.5)) # Pull the particles to the bottom edge.
for i in range(80):
s.append(
Spark(
x = 300,
y = 400,
mass = random(5.0,10.0), # Heavier particles are repulsed harder.
radius = 5, # But doesn't mean they appear bigger.
life = 200 # Particles whither away after 200 frames.
))
# A repulsive force between all particles.
# When particles are very close to each other, forces can be very strong,
# causing particles to move offscreen before anything can be observed.
# This can be tweaked with the threshold (
# which is the minimum distance at which the force operates).
# Add the upper directory (where the nodebox module is) to the search path.
import os, sys; sys.path.insert(0, os.path.join("..",".."))
from nodebox.graphics import *
from nodebox.graphics.physics import Particle, Spring, System
# A "particle system" is used to simulate effects such as explosions, smoke, water, ...
# It consists of object with a mass (particles) that are subjected to forces
# (attractive, repulsive, spring-based).
# In this case,
# the system is a grid (net/tissue) of particles arranged in rows and columns.
s = System()
x = 65 # Horizontal offset.
y = 65 # Vertical offset.
d = 40 # Distance between each particle.
m = 10 # Number of rows.
n = 10 # Number of columns.
for i in range(n):
for j in range(m):
s.append(
Particle(
x = x + i*d,
y = y + j*d, radius=5))
# Spring forces operate on all particles,
# so that when we drag one particle all others are indirectly dragged as well.
# The strength of each spring defines the flexibilty of the resulting fabric.
for i in range(n):
for j in range(m):
p1 = s.particles[i*m + j]
# Add the upper directory (where the nodebox module is) to the search path.
import os, sys
sys.path.insert(0, os.path.join("..", ".."))
from nodebox.graphics import *
from nodebox.graphics.physics import Particle, Spring, System
# A "particle system" is used to simulate effects such as explosions, smoke, water, ...
# It consists of object with a mass (particles) that are subjected to forces
# (attractive, repulsive, spring-based).
# In this case,
# the system is a grid (net/tissue) of particles arranged in rows and columns.
s = System()
x = 65 # Horizontal offset.
y = 65 # Vertical offset.
d = 40 # Distance between each particle.
m = 10 # Number of rows.
n = 10 # Number of columns.
for i in range(n):
for j in range(m):
s.append(Particle(x=x + i * d, y=y + j * d, radius=5))
# Spring forces operate on all particles,
# so that when we drag one particle all others are indirectly dragged as well.
# The strength of each spring defines the flexibilty of the resulting fabric.
for i in range(n):
for j in range(m):
p1 = s.particles[i * m + j]
if i < (n - 1):
p2 = s.particles[(i + 1) * m + j + 0] # Particle to the right.
from nodebox.graphics import *
from nodebox.graphics.physics import Particle, Force, System
# BANG!
# Here is a short example of how the Particle class
# can be subclassed with a custom draw() method:
class Spark(Particle):
def draw(self):
r = self.radius * (1 - self.age)
ellipse(self.x, self.y, r * 2, r * 2)
s = System(gravity=(0, 2.5)) # Pull the particles to the bottom edge.
for i in range(80):
s.append(
Spark(
x=300,
y=400,
mass=random(5.0, 10.0), # Heavier particles are repulsed harder.
radius=5, # But doesn't mean they appear bigger.
life=200 # Particles whither away after 200 frames.
))
# A repulsive force between all particles.
# When particles are very close to each other, forces can be very strong,
# causing particles to move offscreen before anything can be observed.
# This can be tweaked with the threshold (
# which is the minimum distance at which the force operates).
import os, sys
sys.path.insert(0, os.path.join("..",".."))
from nodebox.graphics.context import *
from nodebox.graphics import *
from nodebox.graphics.physics import System, Emitter, Particle, MASS
# 1) An emitter will be firing particles with a constant velocity.
# 2) Drag in the system slows down the particles.
# 3) Gravity then becomes greater than the particles' velocity and they are pulled down.
s = System(gravity=(0, 1.0), drag=0.01)
# The emitter is positioned centrally at the bottom,
# and fires particles upwards in a 30-degrees angle range.
e = Emitter(x=200, y=0, angle=90, strength=10.0, spread=30)
for i in range(100):
# Particles have random mass and lifespan to make it more interesting and diverse.
# The MASS constant means that we want the radius of the visual particle
# to be initialized with the same value as its mass (it's a convenience trick).
# This way we can observe how heavier particles respond.
e.append(Particle(0, 0, mass=random(10,50), radius=MASS, life=random(50,250)))
s.append(e) # Install the emitter in the system.
# Add an obstacle that other particles want to stay away from.
class Obstacle(Particle):
def draw(self):
# The only way to style individual particles is to redefine draw() in a subclass.
# Set the fill color directly for this ellipse, i.e. don't use fill(),
