Merge pull request #28 from cnkeats/xmaslights-tetrahedron

Added xmaslights-tetrahedron.py to /examples/

examples/xmaslights-tetrahedron.py

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+def xmaslight():
+    # This is the code from my 
+
+    #NOTE THE LEDS ARE GRB COLOUR (NOT RGB)
+
+    # Here are the libraries I am currently using:
+    import time
+    import board
+    import neopixel
+    import re
+    import math
+
+    # You are welcome to add any of these:
+    # import random
+    # import numpy
+    # import scipy
+    # import sys
+
+    # If you want to have user changable values, they need to be entered from the command line
+    # so import sys sys and use sys.argv[0] etc
+    # some_value = int(sys.argv[0])
+
+    # IMPORT THE COORDINATES (please don't break this bit)
+
+    coordfilename = "Python/coords.txt"
+
+    fin = open(coordfilename,'r')
+    coords_raw = fin.readlines()
+
+    coords_bits = [i.split(",") for i in coords_raw]
+
+    coords = []
+
+    for slab in coords_bits:
+        new_coord = []
+        for i in slab:
+            new_coord.append(int(re.sub(r'[^-\d]','', i)))
+        coords.append(new_coord)
+
+    #set up the pixels (AKA 'LEDs')
+    PIXEL_COUNT = len(coords) # this should be 500
+
+    pixels = neopixel.NeoPixel(board.D18, PIXEL_COUNT, auto_write=False)
+
+
+    # YOU CAN EDIT FROM HERE DOWN
+
+    # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #
+    #
+    # Authors: Calvin Keats, Matt Parker, Eugénie von Tunzelmann
+    # Date: 12/23/2020
+    #
+    # A spinning tetrahedron to light up Matt Parker's Christmas Tree!
+    # Code modified from: https://github.com/standupmaths/xmastree2020/blob/main/xmaslights-spin.py
+    # 
+    # Watch Matt's video: https://www.youtube.com/watch?v=TvlpIojusBE
+    #
+    # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #
+
+    import numpy as np
+
+    # This function tells you if a given point is on the same side of a triangle (v1, v2, v3) as the point v4
+    def sameSide(v1, v2, v3, v4, point):
+
+        normal = np.cross(np.subtract(v2, v1), np.subtract(v3, v1))
+        dotv4 = np.dot(normal, np.subtract(v4, v1))
+        dotpoint = np.dot(normal, np.subtract(point, v1))
+
+        return (np.sign(dotv4) == np.sign(dotpoint))
+
+    # By checking a point against all the faces of a tetrahedron, we can tell if the point is inside or outside
+    def pointInsideTetrahedron(v1, v2, v3, v4, point):
+        return (sameSide(v1, v2, v3, v4, point) and
+                sameSide(v2, v3, v4, v1, point) and
+                sameSide(v3, v4, v1, v2, point) and
+                sameSide(v4, v1, v2, v3, point))
+
+    # This function rotates a point by 3 angles from their respective axes
+    def matrixRotate(point, xAngle, yAngle, zAngle):
+        v1 = np.array([[point[0]], [point[1]], [point[2]]])
+
+        xAngle = math.radians(xAngle)
+        yAngle = math.radians(yAngle)
+        zAngle = math.radians(zAngle)
+
+        xRotation = np.array([
+            [1, 0, 0],
+            [0, np.cos(xAngle), -np.sin(xAngle)],
+            [0, np.sin(xAngle), np.cos(xAngle)]
+        ])
+
+        yRotation = np.array([
+            [np.cos(yAngle), 0, np.sin(yAngle)],
+            [0, 1, 0],
+            [-np.sin(yAngle), 0, np.cos(yAngle)]
+        ])
+
+        zRotation = np.array([
+            [np.cos(zAngle), -np.sin(zAngle), 0],
+            [np.sin(zAngle), np.cos(zAngle), 0],
+            [0, 0, 1]
+        ])
+
+        v2 = zRotation.dot(yRotation.dot(xRotation.dot(v1)))
+        return v2[0][0], v2[1][0], v2[2][0]
+
+    # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #
+    #
+    # Adjust these values to change the effect!
+    #
+    # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #
+
+    # Inside and outside colors in GRB
+    insideColor = [115, 230, 0] # orange
+    outsideColor = [0, 31, 77] # dark purple
+
+    # Scale of the tetrahedron
+    scale = 400
+
+    # Offset of the tetrahedron. (0, 0, 0) will make it centered on the origin
+    # Note that the tetrahedron does not rotate about its own center, but uses the various axes
+    #   and so offsetting it means it won't rotate in-place
+    xOffset = 0
+    yOffset = 0
+    zOffset = .4
+
+    # The change of the angle per update in DEGREES
+    # Rotations apply in the order X -> Y -> Z because I'm bad at quaternions
+    xAngleChange = 5
+    yAngleChange = 10
+    zAngleChange = 15
+
+    # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #
+    #
+    # Update the LEDs!
+    #
+    # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #
+
+    frame = 0
+
+    run = 1
+    while run == 1:
+
+        tetrahedron = [
+            [(-1 + xOffset) * scale, (0 + yOffset) * scale, (-1/1.414 + zOffset) * scale],
+            [(1 + xOffset) * scale, (0 + yOffset) * scale, (-1/1.414 + zOffset) * scale],
+            [(0 + xOffset) * scale, (-1 + yOffset) * scale, (1/1.414 + zOffset) * scale],
+            [(0 + xOffset) * scale, (1 + yOffset) * scale, (1/1.414 + zOffset) * scale]
+        ]
+
+        # Vertices of our tetrahedron, with the applied rotation
+        tetrahedron = [
+            matrixRotate(tetrahedron[0], xAngleChange * frame, yAngleChange * frame , zAngleChange * frame),
+            matrixRotate(tetrahedron[1], xAngleChange * frame, yAngleChange * frame , zAngleChange * frame),
+            matrixRotate(tetrahedron[2],  xAngleChange * frame, yAngleChange * frame , zAngleChange * frame),
+            matrixRotate(tetrahedron[3],  xAngleChange * frame , yAngleChange * frame , zAngleChange * frame)
+        ]
+
+        LED = 0
+        for coord in coords:
+            if (pointInsideTetrahedron(tetrahedron[0], tetrahedron[1], tetrahedron[2], tetrahedron[3], coord)):
+                pixels[LED] = insideColor
+            else:
+                pixels[LED] = outsideColor
+            LED += 1
+
+        # Send out the updates to the lights
+        pixels.show()
+
+        frame += 1
+
+    return 'DONE'
+
+
+# yes, I just put this at the bottom so it auto runs
+xmaslight()