diff options
Diffstat (limited to 'intern/cycles/kernel/osl/shaders/node_sky_texture.osl')
| -rw-r--r-- | intern/cycles/kernel/osl/shaders/node_sky_texture.osl | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/intern/cycles/kernel/osl/shaders/node_sky_texture.osl b/intern/cycles/kernel/osl/shaders/node_sky_texture.osl new file mode 100644 index 00000000000..43d7bd36973 --- /dev/null +++ b/intern/cycles/kernel/osl/shaders/node_sky_texture.osl @@ -0,0 +1,237 @@ +/* + * Copyright 2011-2013 Blender Foundation + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "node_color.h" +#include "stdcycles.h" + +float sky_angle_between(float thetav, float phiv, float theta, float phi) +{ + float cospsi = sin(thetav) * sin(theta) * cos(phi - phiv) + cos(thetav) * cos(theta); + + if (cospsi > 1.0) + return 0.0; + if (cospsi < -1.0) + return M_PI; + + return acos(cospsi); +} + +vector sky_spherical_coordinates(vector dir) +{ + return vector(acos(dir[2]), atan2(dir[0], dir[1]), 0); +} + +/* Preetham */ +float sky_perez_function(float lam[9], float theta, float gamma) +{ + float ctheta = cos(theta); + float cgamma = cos(gamma); + + return (1.0 + lam[0] * exp(lam[1] / ctheta)) * + (1.0 + lam[2] * exp(lam[3] * gamma) + lam[4] * cgamma * cgamma); +} + +color sky_radiance_preetham(normal dir, + float sunphi, + float suntheta, + color radiance, + float config_x[9], + float config_y[9], + float config_z[9]) +{ + /* convert vector to spherical coordinates */ + vector spherical = sky_spherical_coordinates(dir); + float theta = spherical[0]; + float phi = spherical[1]; + + /* angle between sun direction and dir */ + float gamma = sky_angle_between(theta, phi, suntheta, sunphi); + + /* clamp theta to horizon */ + theta = min(theta, M_PI_2 - 0.001); + + /* compute xyY color space values */ + float x = radiance[1] * sky_perez_function(config_y, theta, gamma); + float y = radiance[2] * sky_perez_function(config_z, theta, gamma); + float Y = radiance[0] * sky_perez_function(config_x, theta, gamma); + + /* convert to RGB */ + color xyz = xyY_to_xyz(x, y, Y); + return xyz_to_rgb(xyz[0], xyz[1], xyz[2]); +} + +/* Hosek / Wilkie */ +float sky_radiance_internal(float config[9], float theta, float gamma) +{ + float ctheta = cos(theta); + float cgamma = cos(gamma); + + float expM = exp(config[4] * gamma); + float rayM = cgamma * cgamma; + float mieM = (1.0 + rayM) / pow((1.0 + config[8] * config[8] - 2.0 * config[8] * cgamma), 1.5); + float zenith = sqrt(ctheta); + + return (1.0 + config[0] * exp(config[1] / (ctheta + 0.01))) * + (config[2] + config[3] * expM + config[5] * rayM + config[6] * mieM + config[7] * zenith); +} + +color sky_radiance_hosek(normal dir, + float sunphi, + float suntheta, + color radiance, + float config_x[9], + float config_y[9], + float config_z[9]) +{ + /* convert vector to spherical coordinates */ + vector spherical = sky_spherical_coordinates(dir); + float theta = spherical[0]; + float phi = spherical[1]; + + /* angle between sun direction and dir */ + float gamma = sky_angle_between(theta, phi, suntheta, sunphi); + + /* clamp theta to horizon */ + theta = min(theta, M_PI_2 - 0.001); + + /* compute xyz color space values */ + float x = sky_radiance_internal(config_x, theta, gamma) * radiance[0]; + float y = sky_radiance_internal(config_y, theta, gamma) * radiance[1]; + float z = sky_radiance_internal(config_z, theta, gamma) * radiance[2]; + + /* convert to RGB and adjust strength */ + return xyz_to_rgb(x, y, z) * (M_2PI / 683); +} + +/* Nishita improved */ +vector geographical_to_direction(float lat, float lon) +{ + return vector(cos(lat) * cos(lon), cos(lat) * sin(lon), sin(lat)); +} + +float precise_angle(vector a, vector b) +{ + return 2.0 * atan2(length(a - b), length(a + b)); +} + +color sky_radiance_nishita(vector dir, float nishita_data[10], string filename) +{ + /* definitions */ + float sun_elevation = nishita_data[6]; + float sun_rotation = nishita_data[7]; + float angular_diameter = nishita_data[8]; + float sun_intensity = nishita_data[9]; + int sun_disc = angular_diameter > 0; + float alpha = 1.0; + color xyz; + /* convert dir to spherical coordinates */ + vector direction = sky_spherical_coordinates(dir); + + /* render above the horizon */ + if (dir[2] >= 0.0) { + /* definitions */ + vector sun_dir = geographical_to_direction(sun_elevation, sun_rotation + M_PI_2); + float sun_dir_angle = precise_angle(dir, sun_dir); + float half_angular = angular_diameter / 2.0; + float dir_elevation = M_PI_2 - direction[0]; + + /* if ray inside sun disc render it, otherwise render sky */ + if (sun_dir_angle < half_angular && sun_disc == 1) { + /* get 2 pixels data */ + color pixel_bottom = color(nishita_data[0], nishita_data[1], nishita_data[2]); + color pixel_top = color(nishita_data[3], nishita_data[4], nishita_data[5]); + float y; + + /* sun interpolation */ + if (sun_elevation - half_angular > 0.0) { + if ((sun_elevation + half_angular) > 0.0) { + y = ((dir_elevation - sun_elevation) / angular_diameter) + 0.5; + xyz = mix(pixel_bottom, pixel_top, y) * sun_intensity; + } + } + else { + if (sun_elevation + half_angular > 0.0) { + y = dir_elevation / (sun_elevation + half_angular); + xyz = mix(pixel_bottom, pixel_top, y) * sun_intensity; + } + } + /* limb darkening, coefficient is 0.6f */ + float angle_fraction = sun_dir_angle / half_angular; + float limb_darkening = (1.0 - 0.6 * (1.0 - sqrt(1.0 - angle_fraction * angle_fraction))); + xyz *= limb_darkening; + } + /* sky */ + else { + /* sky interpolation */ + float x = (direction[1] + M_PI + sun_rotation) / M_2PI; + /* more pixels toward horizon compensation */ + float y = 1.0 - sqrt(dir_elevation / M_PI_2); + if (x > 1.0) { + x = x - 1.0; + } + xyz = (color)texture(filename, x, y, "wrap", "clamp", "interp", "linear", "alpha", alpha); + } + } + /* ground */ + else { + if (dir[2] < -0.4) { + xyz = color(0, 0, 0); + } + else { + /* black ground fade */ + float mul = pow(1.0 + dir[2] * 2.5, 3.0); + /* interpolation */ + float x = (direction[1] + M_PI + sun_rotation) / M_2PI; + float y = 1.5; + if (x > 1.0) { + x = x - 1.0; + } + xyz = (color)texture( + filename, x, y, "wrap", "periodic", "interp", "linear", "alpha", alpha) * + mul; + } + } + /* convert to RGB */ + return xyz_to_rgb(xyz[0], xyz[1], xyz[2]); +} + +shader node_sky_texture( + int use_mapping = 0, + matrix mapping = matrix(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0), + vector Vector = P, + string sky_type = "hosek_wilkie", + float theta = 0.0, + float phi = 0.0, + string filename = "", + color radiance = color(0.0, 0.0, 0.0), + float config_x[9] = {0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0}, + float config_y[9] = {0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0}, + float config_z[9] = {0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0}, + float nishita_data[10] = {0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0}, + output color Color = color(0.0, 0.0, 0.0)) +{ + vector p = Vector; + + if (use_mapping) + p = transform(mapping, p); + + if (sky_type == "nishita_improved") + Color = sky_radiance_nishita(p, nishita_data, filename); + if (sky_type == "hosek_wilkie") + Color = sky_radiance_hosek(p, phi, theta, radiance, config_x, config_y, config_z); + if (sky_type == "preetham") + Color = sky_radiance_preetham(p, phi, theta, radiance, config_x, config_y, config_z); +} |