154 lines
6.1 KiB
Python
154 lines
6.1 KiB
Python
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from math import *
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import numpy as np
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import sys
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import json
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from tqdm import tqdm, trange
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EPS = sys.float_info.epsilon
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class Triangle:
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def __init__(self, v1, v2, v3):
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# Vertices
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self.v1 = v1
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self.v2 = v2
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self.v3 = v3
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# Sort triangle vertices so that so that the normal points "outward"
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if np.dot(self.v1, np.cross(self.v2 - self.v1, self.v3 - self.v1)) < 0:
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self.v3, self.v2 = self.v2, self.v3
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# Edges of the origin vertex and their L2 norms
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self.e1 = self.v2 - self.v1
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self.e2 = self.v3 - self.v1
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self.e1n = np.linalg.norm(self.e1)
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self.e2n = np.linalg.norm(self.e2)
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# Normal vector of the triangle's plane
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self.n = np.cross(self.e1 / self.e1n, self.e2 / self.e2n)
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self.n = self.n / np.linalg.norm(self.n)
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# The vertex coordinates in plane coordinates
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self.v1p = self.plane_coords(self.v1)
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self.v2p = self.plane_coords(self.v2)
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self.v3p = self.plane_coords(self.v3)
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def intersect(self, ray):
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'''
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:param ray: numpy.array(3) Ray cast from [0, 0, 0]
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:return: A tuple of [bool, Optional[numpy.array(3)]]:
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The first component is True if the ray intersects the triangle, False otherwise.
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The second component marks the intersection of the triangle's plane (even if outside the triangle), or
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None if the ray does not intersect the plane at all.
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'''
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# https://en.wikipedia.org/wiki/Möller–Trumbore_intersection_algorithm
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ray_cross_e2 = np.cross(ray, self.e2)
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dot = np.dot(self.e1, ray_cross_e2)
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if abs(dot) < EPS:
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return False, None
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s = -self.v1
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u = np.dot(s, ray_cross_e2) / dot
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s_cross_e1 = np.cross(s, self.e1)
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v = np.dot(ray, s_cross_e1) / dot
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t = np.dot(self.e2, s_cross_e1) / dot
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if (u < 0 and abs(u) > EPS) or (u > 1 and abs(u - 1) > EPS):
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return False, ray * t
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if (v < 0 and abs(v) > EPS) or (u + v > 1 and abs(u + v - 1) > EPS):
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return False, ray * t
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if t <= EPS:
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return False, None
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return True, ray * t
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def plane_coords(self, v):
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u = np.dot(self.e1 / self.e1n, v - self.v1)
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n = np.cross(self.n, self.e1 / self.e1n)
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v = -np.dot(n, v - self.v1)
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return np.array([u, v])
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class Face:
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def __init__(self, vs):
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self.vertices = vs
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self.tris = []
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for i in range(1, len(vs)-1):
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self.tris.append(Triangle(vs[0], vs[i], vs[i+1]))
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self.plane_coords = [self.tris[0].plane_coords(v) for v in self.vertices]
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def convert_to_cartesian(lon, lat):
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x = cos(lon*pi/180)
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y = sin(lon*pi/180)
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z = tan(lat*pi/180)
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mag = sqrt(x**2 + y**2 + z**2)
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return np.array([x/mag, y/mag, z/mag])
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def map_poly(tri, poly, ref=None):
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if ref is None:
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ref = tri
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p0 = convert_to_cartesian(*poly[0])
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p0b, p0i = tri.intersect(p0)
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mapped = []
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new = True
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for i in range(1, len(poly)):
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p1 = convert_to_cartesian(*poly[i])
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p1b, p1i = tri.intersect(p1)
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if p0b or p1b and p0i is not None and p1i is not None:
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if new:
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mapped.append([ref.plane_coords(p0i), ref.plane_coords(p1i)])
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new = False
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else:
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mapped[-1].append(ref.plane_coords(p1i))
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else:
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new = True
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p0 = p1
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p0i = p1i
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p0b = p1b
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return mapped
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if __name__ == '__main__':
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fs = [Face([a, b, c, d]) for a, b, c, d in [
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(np.array([1,1,1]), np.array([-1,1,1]), np.array([-1,-1,1]), np.array([1,-1,1])), # top
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(np.array([1,1,-1]), np.array([-1,1,-1]), np.array([-1,-1,-1]), np.array([1,-1,-1])), # bottom
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(np.array([-1,-1,-1]), np.array([-1,1,-1]), np.array([-1,1,1]), np.array([-1,-1,1])), # left
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(np.array([1,-1,-1]), np.array([1,1,-1]), np.array([1,1,1]), np.array([1,-1,1])), # right
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(np.array([-1,-1,-1]), np.array([1,-1,-1]), np.array([1,-1,1]), np.array([-1,-1,1])), # front
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(np.array([-1,1,-1]), np.array([1,1,-1]), np.array([1,1,1]), np.array([-1,1,1])), # back
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]]
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with open('countries.geojson', 'r') as f:
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j = json.load(f)
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for i, face in tqdm(list(enumerate(fs)), desc='Faces '):
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countries = {}
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for t in face.tris:
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for f in tqdm(j['features'], desc='Features', total=len(face.tris)*len(j['features'])):
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cc = f['properties']['ADMIN']
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if f['geometry']['type'] == 'MultiPolygon':
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for poly in f['geometry']['coordinates']:
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countries.setdefault(cc, []).extend(map_poly(t, poly[0], face.tris[0]))
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elif f['geometry']['type'] == 'Polygon':
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countries.setdefault(cc, []).extend(map_poly(t, f['geometry']['coordinates'][0], face.tris[0]))
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minx = min(v[0] for v in face.plane_coords)
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miny = min(v[1] for v in face.plane_coords)
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maxx = max(v[0] for v in face.plane_coords)
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maxy = max(v[1] for v in face.plane_coords)
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w = maxx - minx
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h = maxy - miny
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with open(f'face{i}.svg', 'w') as svg:
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svg.write(f'<svg xmlns="http://www.w3.org/2000/svg" viewBox="{minx} {miny} {w} {h}" width="{w}" height="{h}" id="face{i}">\n')
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svg.write(f' <g id="cut">\n <path id="outline" fill="none" stroke="black" stroke-width="0.01" d="M {face.plane_coords[0][0]} {face.plane_coords[0][1]}')
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for v in face.plane_coords[1:]:
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svg.write(f' L {v[0]} {v[1]}')
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svg.write(' Z" />\n </g>\n <g id="engrave">\n')
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for c, l in countries.items():
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if l:
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svg.write(f' <g id="{c}">\n')
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for ls in l:
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svg.write(f' <path fill="none" stroke="red" stroke-width="0.01" d="M {ls[0][0]} {ls[0][1]}')
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for x, y in ls[1:]:
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svg.write(f' L {x} {y}')
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svg.write('" />\n')
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svg.write(' </g>\n')
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svg.write(' </g>\n</svg>\n')
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