def Sample2(self, p: Point3d, u: (float, float), Ns: Normal) -> Point3d:
# Compute coordinate system for sphere sampling
Pcenter = Point3d(0, 0, 0) * self.objectToWorld
wc = (Pcenter - p).get_normalized()
wcX, wcY = Transform.create_coordinateSystem(wc)
# Sample uniformly on sphere if $\pt{}$ is inside it
if (p - Pcenter).get_length_squared() - self.radius * self.radius < 1e-40:
return self.Sample1(u, Ns)
# Sample sphere uniformly inside subtended cone
sinThetaMax2 = self.radius * self.radius / (p - Pcenter).get_length_squared()
cosThetaMax = math.sqrt(max(0.0, 1.0 - sinThetaMax2))
dgSphere = DifferentialGeometry()
thit = 1.0
r = Ray(p, UniformSampleCone2(u, cosThetaMax, wcX, wcY, wc), 1e-3)
b, t = self.get_intersection(r, dgSphere)
# if not b:
#bug
thit = Vector3d.dot(Pcenter - p, r.direction.get_normalized())
ps = r.get_at(thit)
nn = (ps - Pcenter).get_normalized()
Ns.Set(nn)
# if (ReverseOrientation) *ns *= -1.f;
return ps
def __init__(self, dg: DifferentialGeometry, ngeom: Normal):
self.bxdfs = list()
self.dgShading = dg
self.ng = ngeom
self.nn = self.dgShading.normal
# self.sn = self.dgShading.normal
# self.tn = Vector3d.cross(self.nn, self.sn)
self.sn, self.tn = Transform.create_coordinateSystem(self.nn)
def create_spotLight(paramSet: ParamSet, light2world: Transform) -> PointLight:
from maths.matrix44 import Matrix44
from maths.vector4d import Vector4d
I = paramSet.find_spectrum("I", Spectrum(1.0))
sc = paramSet.find_spectrum("scale", Spectrum(1.0))
coneangle = paramSet.find_float("coneangle", 30.0)
conedelta = paramSet.find_float("conedeltaangle", 5.0)
# Compute spotlight world to light transformation
frome = paramSet.find_point("from", Point3d(0.0, 0.0, 0.0))
to = paramSet.find_point("to", Point3d(0.0, 0.0, 1.0))
direction = (to - frome).get_normalized()
du, dv = Transform.create_coordinateSystem(dir)
m = Matrix44.create_from_vector4d(
Vector4d(du.x, du.y, du.z, 0.0),
Vector4d(dv.x, dv.y, dv.z, 0.0),
Vector4d(direction.x, direction.y, direction.z, 0.0),
Vector4d(0.0, 0.0, 0.0, 1.0))
dirToZ = Transform(m)
light2world = light2world * Transform.create_translate(frome.ex, frome.ey, frome.ez) * dirToZ.get_invert()
return SpotLight(light2world, I * sc, coneangle, coneangle - conedelta)
