Opioid

import numpy as np

# Formula from: http://www.brucelindbloom.com/index.html?Eqn_RGB_XYZ_Matrix.html
def rgb_to_xyz(r, g, b, w):
    xyz_r = np.array([r[0] / r[1], 1, (1 - r[0] - r[1]) / r[1]])
    xyz_g = np.array([g[0] / g[1], 1, (1 - g[0] - g[1]) / g[1]])
    xyz_b = np.array([b[0] / b[1], 1, (1 - b[0] - b[1]) / b[1]])
    xyz_w = np.array([w[0] / w[1], 1, (1 - w[0] - w[1]) / w[1]])

    s = xyz_w * np.linalg.inv(np.matrix([xyz_r, xyz_g, xyz_b]))

Opioid

void decomposition_tracking(const Ray& ray, const Material& material, float& t_out, float3& transmittance) { 
    auto const cm = material.control_medium();

    float const rc  = rng_.random_float();
    float const t_c = ray.min_t - std::log(1.f - rc) / cm.minorant_mu_t;

    if (t_c > ray.max_t) {
        t_out = ray.max_t;
        transmittance = float3(1.f);
        return;

Opioid

float3 direct_light(const Ray& ray, const float3& p) {
	// return lighting at this point... 
}

float3 spectral_tracking(const Ray& ray, const Material& material, float3& transmittance) {
	const float d = ray.max_t - ray.min_t;

	float3 w(1.f);
	float t = 0.f;

Opioid

float3 direct_light(const float3& position) {
	// direct light inside volume including phase function and beam transmittance
}

float3 homogeneous2(const Ray& ray, float3& transmittance) {
	float3 radiance(0.f);
	
	if (Algorithm::Tracking == algorithm) {
		const float3 sigma_a = material.absorption(float3::identity());

Opioid

float3 direct_light(const float3& position) {
	// direct light inside volume including phase function and beam transmittance
}

float3 homogeneous(const Ray& ray, float3& transmittance) {
	float3 radiance(0.f);

	const float3 extinction = sigma_a + sigma_s;

	const float3 scattering_albedo = sigma_s / extinction;