mypoint.py

import mitsuba
import enoki as ek
import numpy as np
from math import radians, cos
from mitsuba.core import Point3f, warp, Ray3f, AnimatedTransform
from mitsuba.core.math import Pi
from mitsuba.render import (DirectionSample3f, Emitter,
    SurfaceInteraction3f, EmitterFlags,
    Texture)

class MyPointEmitter(Emitter):
  """docstring for MyPointEmitter"""
  def __init__(self, props):
    # super(MyPointEmitter, props).__init__(props)
    Emitter.__init__(self, props)
    # print(self.m_world_transform)
    self.m_intensity = props['intensity'] # assumption that a texture is returned
    self.m_intensity = Texture.D65(1)
    print(self.m_intensity.class_().name())
    self.m_needs_sample_3 = False
    self.m_flags = +EmitterFlags.DeltaPosition

    # should ideally be inherited from cpp parent class
    self.m_world_transform = AnimatedTransform(props["to_world"])

  def sample_ray(self, time,
      sample1, # wavelength
      sample2, # pos
      sample3, # dir
      active):
    wavelengths, spec_weight = self.m_intensity.sample(SurfaceInteraction3f(), np.arange(sample1), active)
    trafo = self.m_world_transform.eval(ref.time)
    ray = Ray3f(trafo*Point3f(0), warp.square_to_uniform_sphere(sample3),
        time, wavelengths)

    print(spec_weight.class_().name())
    return (ray, spec_weight*4.0*Pi)

  def sample_direction(self, ref, sample, active):
    trafo = self.m_world_transform.eval(ref.time, active)

    ds = DirectionSample3f()
    ds.p = trafo.translation()
    ds.n = 0
    ds.uv = 0
    ds.time = ref.time
    ds.pdf = 1
    ds.delta = True
    ds.d = ds.p - ref.p
    ds.dist = ek.norm(ds.d)
    inv_dist = ek.rcp(ds.dist)
    ds.d *= inv_dist

    si = SurfaceInteraction3f()
    si.wavelengths = ref.wavelengths

    spec = self.m_intensity.eval(si, active)*(inv_dist*inv_dist)
    # print(spec.class_().name())
    return (ds, spec)
  
  def pdf_direction(self, ref, ds, active):
    return 0

  def eval(self, si, active):
    return 0

  def bbox(self):
    return self.m_world_transform.translation_bounds()

  def to_string(self):
    mystr = "MyPointLight\n"
    mystr.append(" world_transform" + self.m_world_transform.to_string())
    mystr.append(" intensity" + self.m_intensity + "\n") 
    return mystr