forked from bartvdbraak/blender
134 lines
4.2 KiB
Plaintext
134 lines
4.2 KiB
Plaintext
/*
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* Copyright 2011-2013 Blender Foundation
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include "stdosl.h"
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#include "node_color.h"
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float sky_angle_between(float thetav, float phiv, float theta, float phi)
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{
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float cospsi = sin(thetav) * sin(theta) * cos(phi - phiv) + cos(thetav) * cos(theta);
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if (cospsi > 1.0)
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return 0.0;
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if (cospsi < -1.0)
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return M_PI;
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return acos(cospsi);
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}
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vector sky_spherical_coordinates(vector dir)
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{
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return vector(acos(dir[2]), atan2(dir[0], dir[1]), 0);
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}
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/* Preetham */
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float sky_perez_function(float lam[9], float theta, float gamma)
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{
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float ctheta = cos(theta);
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float cgamma = cos(gamma);
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return (1.0 + lam[0] * exp(lam[1] / ctheta)) * (1.0 + lam[2] * exp(lam[3] * gamma) + lam[4] * cgamma * cgamma);
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}
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color sky_radiance_old(normal dir,
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float sunphi, float suntheta, color radiance,
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float config_x[9], float config_y[9], float config_z[9])
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{
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/* convert vector to spherical coordinates */
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vector spherical = sky_spherical_coordinates(dir);
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float theta = spherical[0];
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float phi = spherical[1];
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/* angle between sun direction and dir */
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float gamma = sky_angle_between(theta, phi, suntheta, sunphi);
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/* clamp theta to horizon */
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theta = min(theta, M_PI_2 - 0.001);
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/* compute xyY color space values */
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float x = radiance[1] * sky_perez_function(config_y, theta, gamma);
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float y = radiance[2] * sky_perez_function(config_z, theta, gamma);
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float Y = radiance[0] * sky_perez_function(config_x, theta, gamma);
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/* convert to RGB */
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color xyz = xyY_to_xyz(x, y, Y);
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return xyz_to_rgb(xyz[0], xyz[1], xyz[2]);
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}
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/* Hosek / Wilkie */
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float sky_radiance_internal(float config[9], float theta, float gamma)
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{
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float ctheta = cos(theta);
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float cgamma = cos(gamma);
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float expM = exp(config[4] * gamma);
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float rayM = cgamma * cgamma;
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float mieM = (1.0 + rayM) / pow((1.0 + config[8] * config[8] - 2.0 * config[8] * cgamma), 1.5);
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float zenith = sqrt(ctheta);
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return (1.0 + config[0] * exp(config[1] / (ctheta + 0.01))) *
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(config[2] + config[3] * expM + config[5] * rayM + config[6] * mieM + config[7] * zenith);
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}
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color sky_radiance_new(normal dir,
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float sunphi, float suntheta, color radiance,
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float config_x[9], float config_y[9], float config_z[9])
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{
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/* convert vector to spherical coordinates */
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vector spherical = sky_spherical_coordinates(dir);
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float theta = spherical[0];
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float phi = spherical[1];
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/* angle between sun direction and dir */
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float gamma = sky_angle_between(theta, phi, suntheta, sunphi);
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/* clamp theta to horizon */
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theta = min(theta, M_PI_2 - 0.001);
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/* compute xyz color space values */
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float x = sky_radiance_internal(config_x, theta, gamma) * radiance[0];
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float y = sky_radiance_internal(config_y, theta, gamma) * radiance[1];
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float z = sky_radiance_internal(config_z, theta, gamma) * radiance[2];
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/* convert to RGB and adjust strength */
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return xyz_to_rgb(x, y, z) * (M_2PI / 683);
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}
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shader node_sky_texture(
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int use_mapping = 0,
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matrix mapping = matrix(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0),
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vector Vector = P,
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string sky_model = "Hosek / Wilkie",
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float theta = 0.0,
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float phi = 0.0,
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color radiance = color(0.0, 0.0, 0.0),
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float config_x[9] = {0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0},
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float config_y[9] = {0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0},
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float config_z[9] = {0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0},
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output color Color = color(0.0, 0.0, 0.0))
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{
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vector p = Vector;
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if (use_mapping)
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p = transform(mapping, p);
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if (sky_model == "Hosek / Wilkie")
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Color = sky_radiance_new(p, phi, theta, radiance, config_x, config_y, config_z);
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else
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Color = sky_radiance_old(p, phi, theta, radiance, config_x, config_y, config_z);
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}
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