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https://github.com/kuhyx/WUT_Computer_Science.git
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52 lines
1.9 KiB
Python
52 lines
1.9 KiB
Python
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import numpy as np
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from ..utils.constants import *
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from ..utils.vector3 import vec3
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from ..geometry import Primitive, Collider
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class Sphere(Primitive):
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def __init__(self,center, material, radius, max_ray_depth = 5, shadow = True):
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super().__init__(center, material, max_ray_depth, shadow = shadow)
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self.collider_list += [Sphere_Collider(assigned_primitive = self, center = center, radius = radius)]
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self.bounded_sphere_radius = radius
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def get_uv(self, hit):
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return hit.collider.get_uv(hit)
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class Sphere_Collider(Collider):
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def __init__(self, radius, **kwargs):
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super().__init__(**kwargs)
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self.radius = radius
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def intersect(self, O, D):
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b = 2 * D.dot(O - self.center)
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c = self.center.square_length() + O.square_length() - 2 * self.center.dot(O) - (self.radius * self.radius)
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disc = (b ** 2) - (4 * c)
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sq = np.sqrt(np.maximum(0, disc))
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h0 = (-b - sq) / 2
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h1 = (-b + sq) / 2
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h = np.where((h0 > 0) & (h0 < h1), h0, h1)
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pred = (disc > 0) & (h > 0)
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M = (O + D * h)
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NdotD = ((M - self.center) * (1. / self.radius) ).dot(D)
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pred1 = (disc > 0) & (h > 0) & (NdotD > 0)
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pred2 = (disc > 0) & (h > 0) & (NdotD < 0)
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pred3 = True
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#return an array with hit distance and the hit orientation
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return np.select([pred1,pred2,pred3] , [[h, np.tile(UPDOWN, h.shape)], [h,np.tile(UPWARDS, h.shape)], FARAWAY])
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def get_Normal(self, hit):
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# M = intersection point
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return (hit.point - self.center) * (1. / self.radius)
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def get_uv(self, hit):
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M_C = (hit.point - self.center) / self.radius
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phi = np.arctan2(M_C.z, M_C.x)
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theta = np.arcsin(M_C.y)
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u = (phi + np.pi) / (2*np.pi)
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v = (theta + np.pi/2) / np.pi
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return u,v
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