c2e5622d50
These are causing quite a big difference in existing files, which is not
easy to address in versioning. Since the goal of removing this was to
simplify things for us and that's not the case, just revert this change.
This reverts commit ab21755aaf.
Ref #139923
Pull Request: https://projects.blender.org/blender/blender/pulls/146336
329 lines
13 KiB
C++
329 lines
13 KiB
C++
/* SPDX-FileCopyrightText: 2012-2013 Lukas Hosek and Alexander Wilkie. All rights reserved.
|
|
*
|
|
* SPDX-License-Identifier: BSD-3-Clause */
|
|
|
|
/* ============================================================================
|
|
|
|
This file is part of a sample implementation of the analytical skylight and
|
|
solar radiance models presented in the SIGGRAPH 2012 paper
|
|
|
|
|
|
"An Analytic Model for Full Spectral Sky-Dome Radiance"
|
|
|
|
and the 2013 IEEE CG&A paper
|
|
|
|
"Adding a Solar Radiance Function to the Hosek Skylight Model"
|
|
|
|
both by
|
|
|
|
Lukas Hosek and Alexander Wilkie
|
|
Charles University in Prague, Czech Republic
|
|
|
|
|
|
Version: 1.4a, February 22nd, 2013
|
|
|
|
Version history:
|
|
|
|
1.4a February 22nd, 2013
|
|
Removed unnecessary and counter-intuitive solar radius parameters
|
|
from the interface of the color-space sky dome initialization functions.
|
|
|
|
1.4 February 11th, 2013
|
|
Fixed a bug which caused the relative brightness of the solar disc
|
|
and the sky dome to be off by a factor of about 6. The sun was too
|
|
bright: this affected both normal and alien sun scenarios. The
|
|
coefficients of the solar radiance function were changed to fix this.
|
|
|
|
1.3 January 21st, 2013 (not released to the public)
|
|
Added support for solar discs that are not exactly the same size as
|
|
the terrestrial sun. Also added support for suns with a different
|
|
emission spectrum ("Alien World" functionality).
|
|
|
|
1.2a December 18th, 2012
|
|
Fixed a mistake and some inaccuracies in the solar radiance function
|
|
explanations found in ArHosekSkyModel.h. The actual source code is
|
|
unchanged compared to version 1.2.
|
|
|
|
1.2 December 17th, 2012
|
|
Native RGB data and a solar radiance function that matches the turbidity
|
|
conditions were added.
|
|
|
|
1.1 September 2012
|
|
The coefficients of the spectral model are now scaled so that the output
|
|
is given in physical units: W / (m^-2 * sr * nm). Also, the output of the
|
|
XYZ model is now no longer scaled to the range [0...1]. Instead, it is
|
|
the result of a simple conversion from spectral data via the CIE 2 degree
|
|
standard observer matching functions. Therefore, after multiplication
|
|
with 683 lm / W, the Y channel now corresponds to luminance in lm.
|
|
|
|
1.0 May 11th, 2012
|
|
Initial release.
|
|
|
|
|
|
Please visit http://cgg.mff.cuni.cz/projects/SkylightModelling/ to check if
|
|
an updated version of this code has been published!
|
|
|
|
============================================================================ */
|
|
|
|
/*
|
|
|
|
All instructions on how to use this code are in the accompanying header file.
|
|
|
|
*/
|
|
|
|
/** \file
|
|
* \ingroup intern_sky_modal
|
|
*/
|
|
|
|
#include "sky_hosek.h"
|
|
#include "sky_hosek_data.h"
|
|
|
|
#include <cassert>
|
|
#include <cmath>
|
|
#include <cstdlib>
|
|
|
|
// Some macro definitions that occur elsewhere in ART, and that have to be
|
|
// replicated to make this a stand-alone module.
|
|
|
|
#ifndef MATH_PI
|
|
# define MATH_PI 3.141592653589793
|
|
#endif
|
|
|
|
#ifndef MATH_DEG_TO_RAD
|
|
# define MATH_DEG_TO_RAD (MATH_PI / 180.0)
|
|
#endif
|
|
|
|
#ifndef DEGREES
|
|
# define DEGREES *MATH_DEG_TO_RAD
|
|
#endif
|
|
|
|
#ifndef TERRESTRIAL_SOLAR_RADIUS
|
|
# define TERRESTRIAL_SOLAR_RADIUS ((0.51 DEGREES) / 2.0)
|
|
#endif
|
|
|
|
#ifndef ALLOC
|
|
# define ALLOC(_struct) ((_struct *)malloc(sizeof(_struct)))
|
|
#endif
|
|
|
|
/* Not defined on all platforms (macOS & WIN32). */
|
|
using uint = unsigned int;
|
|
|
|
// internal definitions
|
|
|
|
using ArHosekSkyModel_Dataset = const double *;
|
|
using ArHosekSkyModel_Radiance_Dataset = const double *;
|
|
|
|
// internal functions
|
|
|
|
static void ArHosekSkyModel_CookConfiguration(ArHosekSkyModel_Dataset dataset,
|
|
SKY_ArHosekSkyModelConfiguration config,
|
|
double turbidity,
|
|
double albedo,
|
|
double solar_elevation)
|
|
{
|
|
const double *elev_matrix;
|
|
|
|
int int_turbidity = int(turbidity);
|
|
double turbidity_rem = turbidity - double(int_turbidity);
|
|
|
|
solar_elevation = pow(solar_elevation / (MATH_PI / 2.0), (1.0 / 3.0));
|
|
|
|
// alb 0 low turb
|
|
|
|
elev_matrix = dataset + (9 * 6 * (int_turbidity - 1));
|
|
|
|
for (uint i = 0; i < 9; ++i) {
|
|
//(1-t).^3* A1 + 3*(1-t).^2.*t * A2 + 3*(1-t) .* t .^ 2 * A3 + t.^3 * A4;
|
|
config[i] =
|
|
(1.0 - albedo) * (1.0 - turbidity_rem) *
|
|
(pow(1.0 - solar_elevation, 5.0) * elev_matrix[i] +
|
|
5.0 * pow(1.0 - solar_elevation, 4.0) * solar_elevation * elev_matrix[i + 9] +
|
|
10.0 * pow(1.0 - solar_elevation, 3.0) * pow(solar_elevation, 2.0) * elev_matrix[i + 18] +
|
|
10.0 * pow(1.0 - solar_elevation, 2.0) * pow(solar_elevation, 3.0) * elev_matrix[i + 27] +
|
|
5.0 * (1.0 - solar_elevation) * pow(solar_elevation, 4.0) * elev_matrix[i + 36] +
|
|
pow(solar_elevation, 5.0) * elev_matrix[i + 45]);
|
|
}
|
|
|
|
// alb 1 low turb
|
|
elev_matrix = dataset + (9 * 6 * 10 + 9 * 6 * (int_turbidity - 1));
|
|
for (uint i = 0; i < 9; ++i) {
|
|
//(1-t).^3* A1 + 3*(1-t).^2.*t * A2 + 3*(1-t) .* t .^ 2 * A3 + t.^3 * A4;
|
|
config[i] +=
|
|
(albedo) * (1.0 - turbidity_rem) *
|
|
(pow(1.0 - solar_elevation, 5.0) * elev_matrix[i] +
|
|
5.0 * pow(1.0 - solar_elevation, 4.0) * solar_elevation * elev_matrix[i + 9] +
|
|
10.0 * pow(1.0 - solar_elevation, 3.0) * pow(solar_elevation, 2.0) * elev_matrix[i + 18] +
|
|
10.0 * pow(1.0 - solar_elevation, 2.0) * pow(solar_elevation, 3.0) * elev_matrix[i + 27] +
|
|
5.0 * (1.0 - solar_elevation) * pow(solar_elevation, 4.0) * elev_matrix[i + 36] +
|
|
pow(solar_elevation, 5.0) * elev_matrix[i + 45]);
|
|
}
|
|
|
|
if (int_turbidity == 10) {
|
|
return;
|
|
}
|
|
|
|
// alb 0 high turb
|
|
elev_matrix = dataset + (9 * 6 * (int_turbidity));
|
|
for (uint i = 0; i < 9; ++i) {
|
|
//(1-t).^3* A1 + 3*(1-t).^2.*t * A2 + 3*(1-t) .* t .^ 2 * A3 + t.^3 * A4;
|
|
config[i] +=
|
|
(1.0 - albedo) * (turbidity_rem) *
|
|
(pow(1.0 - solar_elevation, 5.0) * elev_matrix[i] +
|
|
5.0 * pow(1.0 - solar_elevation, 4.0) * solar_elevation * elev_matrix[i + 9] +
|
|
10.0 * pow(1.0 - solar_elevation, 3.0) * pow(solar_elevation, 2.0) * elev_matrix[i + 18] +
|
|
10.0 * pow(1.0 - solar_elevation, 2.0) * pow(solar_elevation, 3.0) * elev_matrix[i + 27] +
|
|
5.0 * (1.0 - solar_elevation) * pow(solar_elevation, 4.0) * elev_matrix[i + 36] +
|
|
pow(solar_elevation, 5.0) * elev_matrix[i + 45]);
|
|
}
|
|
|
|
// alb 1 high turb
|
|
elev_matrix = dataset + (9 * 6 * 10 + 9 * 6 * (int_turbidity));
|
|
for (uint i = 0; i < 9; ++i) {
|
|
//(1-t).^3* A1 + 3*(1-t).^2.*t * A2 + 3*(1-t) .* t .^ 2 * A3 + t.^3 * A4;
|
|
config[i] +=
|
|
(albedo) * (turbidity_rem) *
|
|
(pow(1.0 - solar_elevation, 5.0) * elev_matrix[i] +
|
|
5.0 * pow(1.0 - solar_elevation, 4.0) * solar_elevation * elev_matrix[i + 9] +
|
|
10.0 * pow(1.0 - solar_elevation, 3.0) * pow(solar_elevation, 2.0) * elev_matrix[i + 18] +
|
|
10.0 * pow(1.0 - solar_elevation, 2.0) * pow(solar_elevation, 3.0) * elev_matrix[i + 27] +
|
|
5.0 * (1.0 - solar_elevation) * pow(solar_elevation, 4.0) * elev_matrix[i + 36] +
|
|
pow(solar_elevation, 5.0) * elev_matrix[i + 45]);
|
|
}
|
|
}
|
|
|
|
static double ArHosekSkyModel_CookRadianceConfiguration(ArHosekSkyModel_Radiance_Dataset dataset,
|
|
double turbidity,
|
|
double albedo,
|
|
double solar_elevation)
|
|
{
|
|
const double *elev_matrix;
|
|
|
|
int int_turbidity = int(turbidity);
|
|
double turbidity_rem = turbidity - double(int_turbidity);
|
|
double res;
|
|
solar_elevation = pow(solar_elevation / (MATH_PI / 2.0), (1.0 / 3.0));
|
|
|
|
// alb 0 low turb
|
|
elev_matrix = dataset + (6 * (int_turbidity - 1));
|
|
//(1-t).^3* A1 + 3*(1-t).^2.*t * A2 + 3*(1-t) .* t .^ 2 * A3 + t.^3 * A4;
|
|
res = (1.0 - albedo) * (1.0 - turbidity_rem) *
|
|
(pow(1.0 - solar_elevation, 5.0) * elev_matrix[0] +
|
|
5.0 * pow(1.0 - solar_elevation, 4.0) * solar_elevation * elev_matrix[1] +
|
|
10.0 * pow(1.0 - solar_elevation, 3.0) * pow(solar_elevation, 2.0) * elev_matrix[2] +
|
|
10.0 * pow(1.0 - solar_elevation, 2.0) * pow(solar_elevation, 3.0) * elev_matrix[3] +
|
|
5.0 * (1.0 - solar_elevation) * pow(solar_elevation, 4.0) * elev_matrix[4] +
|
|
pow(solar_elevation, 5.0) * elev_matrix[5]);
|
|
|
|
// alb 1 low turb
|
|
elev_matrix = dataset + (6 * 10 + 6 * (int_turbidity - 1));
|
|
//(1-t).^3* A1 + 3*(1-t).^2.*t * A2 + 3*(1-t) .* t .^ 2 * A3 + t.^3 * A4;
|
|
res += (albedo) * (1.0 - turbidity_rem) *
|
|
(pow(1.0 - solar_elevation, 5.0) * elev_matrix[0] +
|
|
5.0 * pow(1.0 - solar_elevation, 4.0) * solar_elevation * elev_matrix[1] +
|
|
10.0 * pow(1.0 - solar_elevation, 3.0) * pow(solar_elevation, 2.0) * elev_matrix[2] +
|
|
10.0 * pow(1.0 - solar_elevation, 2.0) * pow(solar_elevation, 3.0) * elev_matrix[3] +
|
|
5.0 * (1.0 - solar_elevation) * pow(solar_elevation, 4.0) * elev_matrix[4] +
|
|
pow(solar_elevation, 5.0) * elev_matrix[5]);
|
|
if (int_turbidity == 10) {
|
|
return res;
|
|
}
|
|
|
|
// alb 0 high turb
|
|
elev_matrix = dataset + (6 * (int_turbidity));
|
|
//(1-t).^3* A1 + 3*(1-t).^2.*t * A2 + 3*(1-t) .* t .^ 2 * A3 + t.^3 * A4;
|
|
res += (1.0 - albedo) * (turbidity_rem) *
|
|
(pow(1.0 - solar_elevation, 5.0) * elev_matrix[0] +
|
|
5.0 * pow(1.0 - solar_elevation, 4.0) * solar_elevation * elev_matrix[1] +
|
|
10.0 * pow(1.0 - solar_elevation, 3.0) * pow(solar_elevation, 2.0) * elev_matrix[2] +
|
|
10.0 * pow(1.0 - solar_elevation, 2.0) * pow(solar_elevation, 3.0) * elev_matrix[3] +
|
|
5.0 * (1.0 - solar_elevation) * pow(solar_elevation, 4.0) * elev_matrix[4] +
|
|
pow(solar_elevation, 5.0) * elev_matrix[5]);
|
|
|
|
// alb 1 high turb
|
|
elev_matrix = dataset + (6 * 10 + 6 * (int_turbidity));
|
|
//(1-t).^3* A1 + 3*(1-t).^2.*t * A2 + 3*(1-t) .* t .^ 2 * A3 + t.^3 * A4;
|
|
res += (albedo) * (turbidity_rem) *
|
|
(pow(1.0 - solar_elevation, 5.0) * elev_matrix[0] +
|
|
5.0 * pow(1.0 - solar_elevation, 4.0) * solar_elevation * elev_matrix[1] +
|
|
10.0 * pow(1.0 - solar_elevation, 3.0) * pow(solar_elevation, 2.0) * elev_matrix[2] +
|
|
10.0 * pow(1.0 - solar_elevation, 2.0) * pow(solar_elevation, 3.0) * elev_matrix[3] +
|
|
5.0 * (1.0 - solar_elevation) * pow(solar_elevation, 4.0) * elev_matrix[4] +
|
|
pow(solar_elevation, 5.0) * elev_matrix[5]);
|
|
return res;
|
|
}
|
|
|
|
static double ArHosekSkyModel_GetRadianceInternal(
|
|
const SKY_ArHosekSkyModelConfiguration configuration, const double theta, const double gamma)
|
|
{
|
|
const double expM = exp(configuration[4] * gamma);
|
|
const double rayM = cos(gamma) * cos(gamma);
|
|
const double mieM =
|
|
(1.0 + cos(gamma) * cos(gamma)) /
|
|
pow((1.0 + configuration[8] * configuration[8] - 2.0 * configuration[8] * cos(gamma)), 1.5);
|
|
const double zenith = sqrt(cos(theta));
|
|
|
|
return (1.0 + configuration[0] * exp(configuration[1] / (cos(theta) + 0.01))) *
|
|
(configuration[2] + configuration[3] * expM + configuration[5] * rayM +
|
|
configuration[6] * mieM + configuration[7] * zenith);
|
|
}
|
|
|
|
void SKY_arhosekskymodelstate_free(SKY_ArHosekSkyModelState *state)
|
|
{
|
|
free(state);
|
|
}
|
|
|
|
double SKY_arhosekskymodel_radiance(SKY_ArHosekSkyModelState *state,
|
|
double theta,
|
|
double gamma,
|
|
double wavelength)
|
|
{
|
|
int low_wl = int((wavelength - 320.0) / 40.0);
|
|
|
|
if (low_wl < 0 || low_wl >= 11) {
|
|
return 0.0;
|
|
}
|
|
|
|
double interp = fmod((wavelength - 320.0) / 40.0, 1.0);
|
|
|
|
double val_low = ArHosekSkyModel_GetRadianceInternal(state->configs[low_wl], theta, gamma) *
|
|
state->radiances[low_wl] * state->emission_correction_factor_sky[low_wl];
|
|
|
|
if (interp < 1e-6) {
|
|
return val_low;
|
|
}
|
|
|
|
double result = (1.0 - interp) * val_low;
|
|
|
|
if (low_wl + 1 < 11) {
|
|
result += interp *
|
|
ArHosekSkyModel_GetRadianceInternal(state->configs[low_wl + 1], theta, gamma) *
|
|
state->radiances[low_wl + 1] * state->emission_correction_factor_sky[low_wl + 1];
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
// xyz and rgb versions
|
|
|
|
SKY_ArHosekSkyModelState *SKY_arhosek_xyz_skymodelstate_alloc_init(const double turbidity,
|
|
const double albedo,
|
|
const double elevation)
|
|
{
|
|
SKY_ArHosekSkyModelState *state = ALLOC(SKY_ArHosekSkyModelState);
|
|
|
|
state->solar_radius = TERRESTRIAL_SOLAR_RADIUS;
|
|
state->turbidity = turbidity;
|
|
state->albedo = albedo;
|
|
state->elevation = elevation;
|
|
|
|
for (uint channel = 0; channel < 3; ++channel) {
|
|
ArHosekSkyModel_CookConfiguration(
|
|
datasetsXYZ[channel], state->configs[channel], turbidity, albedo, elevation);
|
|
|
|
state->radiances[channel] = ArHosekSkyModel_CookRadianceConfiguration(
|
|
datasetsXYZRad[channel], turbidity, albedo, elevation);
|
|
}
|
|
|
|
return state;
|
|
}
|