Add functioning particle system

Author: NicoooByte

.gitignore

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+/Export/
+!/Export/example.gif

Export/example.gif

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-# SimpleParticles
+# SimpleParticles
+
+Creates a simple particle system and periodically changes the force field to keep things interesting. 
+
+![Example](./Export/example.gif)

README.md

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+import numpy as np
+import matplotlib.pyplot as plt
+from scipy.ndimage import gaussian_filter
+
+BOUNDS = 1024
+FILTER_SIGMA = 12
+FRAMES = 30
+#np.random.seed(2)
+
+class SimpleParticles():
+    ''' Creates a grid filled with particles an a force field with gaussian blur applied to it
+    '''
+    def __init__(self, bounds, filter_sigma):
+        self.particleForceX_unblurred = np.random.random(size=[bounds,bounds])
+        self.particleForceX = gaussian_filter(self.particleForceX_unblurred, sigma=filter_sigma)
+        self.particleForceY_unblurred = np.random.random(size=[bounds,bounds])
+        self.particleForceY = gaussian_filter(self.particleForceY_unblurred, sigma=filter_sigma)
+        self.particles = (np.random.random(size=[bounds,bounds]) - 0.4).round()
+        
+        self.bounds = bounds
+        self.filter_sigma = filter_sigma
+
+    def change_force_field(self):
+        # for x, particleRow in enumerate(self.particleForceX_unblurred):
+        #     for y, particle in enumerate(particleRow):
+        #         particle = 1 - particle
+        # self.particleForceX = gaussian_filter(self.particleForceX_unblurred, sigma=FILTER_SIGMA)
+        # with np.nditer(self.particleForceY_unblurred, op_flags=['readwrite']) as it:
+        #     for y in it:
+        #         y[...] = 1 - y
+        # self.particleForceY = gaussian_filter(self.particleForceY_unblurred, sigma=FILTER_SIGMA)
+        self.particleForceX_unblurred = np.random.random(size=[BOUNDS,BOUNDS])
+        self.particleForceX = gaussian_filter(self.particleForceX_unblurred, sigma=FILTER_SIGMA)
+        self.particleForceY_unblurred = np.random.random(size=[BOUNDS,BOUNDS])
+        self.particleForceY = gaussian_filter(self.particleForceY_unblurred, sigma=FILTER_SIGMA)
+
+    def move_particle(self, x, y, recursion=False):
+        ''' Moves a particle according to the force exhibited by the force field. 
+            If the destination is not free the function gets called recursively and "pushes" the particles forward along the force grid.
+            particle values:
+                * 1 -> normal value, not changed since last frame was rendered
+                * 1.2 -> value once the particle has changed position
+                * 1.3 -> value for loops within the system, no movement for this particles 
+        '''
+        vector = self.get_force_vector(x, y)
+        particle_dest = [x + vector[0], y + vector[1]]
+        if particle_dest[0] > BOUNDS - 1:
+            particle_dest[0] -= BOUNDS
+        if particle_dest[1] > BOUNDS - 1:
+            particle_dest[1] -= BOUNDS
+
+        particle_dest_value = self.particles[particle_dest[0], particle_dest[1]]
+        
+        if particle_dest_value == 1.2:
+            self.particles[x, y] = 1.2
+            return False
+    
+        if particle_dest_value == 1 or particle_dest_value == 1.3:
+            self.particles[x, y] = 1.2
+            if self.move_particle(particle_dest[0], particle_dest[1], True) is False:
+                self.particles[x, y] = 1.2
+                return False
+
+        self.particles[x, y] = 0
+        self.particles[particle_dest[0], particle_dest[1]] = 1.2 if recursion else 1.3
+
+    def get_force_vector(self, x, y):
+        ''' Calculates the force vector based on the force grid.
+        '''
+        vector = [0, 0]
+        if self.particleForceX[x, y] > 0.5:
+            vector[0] = 1
+        elif self.particleForceX[x, y] <= 0.5:
+            vector[0] = -1
+        if self.particleForceY[x, y] > 0.5:
+            vector[1] = 1
+        elif self.particleForceY[x, y] <= 0.5:
+            vector[1] = -1
+        return vector
+
+    def render(self, frames):
+        ''' Renders the simulation and exports it into "./Export/".
+        '''
+        for i in range(frames):
+            for x, particleRow in enumerate(self.particles):
+                for y, particle in enumerate(particleRow):
+                    if particle != 0 and particle != 1.3: 
+                        self.move_particle(x, y)
+
+            self.particles = self.particles.round()
+            plt.imshow(self.particles)
+            ax = plt.gca()
+            ax.get_yaxis().set_visible(False)
+            ax.get_xaxis().set_visible(False)
+            plt.savefig(fname=f"./Export/Frame-{i}")
+            print(f"Done with Frame {i}")
+            if i % 5 == 0:
+                self.change_force_field()
+
+if __name__ == "__main__":
+    particles = SimpleParticles(BOUNDS, FILTER_SIGMA)
+    particles.render(FRAMES)