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Diffstat (limited to 'intern/cycles/kernel/svm/sky.h')
| -rw-r--r-- | intern/cycles/kernel/svm/sky.h | 335 |
1 files changed, 335 insertions, 0 deletions
diff --git a/intern/cycles/kernel/svm/sky.h b/intern/cycles/kernel/svm/sky.h new file mode 100644 index 00000000000..867fdfc2a3f --- /dev/null +++ b/intern/cycles/kernel/svm/sky.h @@ -0,0 +1,335 @@ +/* + * 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. + */ + +#pragma once + +CCL_NAMESPACE_BEGIN + +/* Sky texture */ + +ccl_device float sky_angle_between(float thetav, float phiv, float theta, float phi) +{ + float cospsi = sinf(thetav) * sinf(theta) * cosf(phi - phiv) + cosf(thetav) * cosf(theta); + return safe_acosf(cospsi); +} + +/* + * "A Practical Analytic Model for Daylight" + * A. J. Preetham, Peter Shirley, Brian Smits + */ +ccl_device float sky_perez_function(ccl_private float *lam, float theta, float gamma) +{ + float ctheta = cosf(theta); + float cgamma = cosf(gamma); + + return (1.0f + lam[0] * expf(lam[1] / ctheta)) * + (1.0f + lam[2] * expf(lam[3] * gamma) + lam[4] * cgamma * cgamma); +} + +ccl_device float3 sky_radiance_preetham(KernelGlobals kg, + float3 dir, + float sunphi, + float suntheta, + float radiance_x, + float radiance_y, + float radiance_z, + ccl_private float *config_x, + ccl_private float *config_y, + ccl_private float *config_z) +{ + /* convert vector to spherical coordinates */ + float2 spherical = direction_to_spherical(dir); + float theta = spherical.x; + float phi = spherical.y; + + /* 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_F - 0.001f); + + /* compute xyY color space values */ + float x = radiance_y * sky_perez_function(config_y, theta, gamma); + float y = radiance_z * sky_perez_function(config_z, theta, gamma); + float Y = radiance_x * sky_perez_function(config_x, theta, gamma); + + /* convert to RGB */ + float3 xyz = xyY_to_xyz(x, y, Y); + return xyz_to_rgb(kg, xyz); +} + +/* + * "An Analytic Model for Full Spectral Sky-Dome Radiance" + * Lukas Hosek, Alexander Wilkie + */ +ccl_device float sky_radiance_internal(ccl_private float *configuration, float theta, float gamma) +{ + float ctheta = cosf(theta); + float cgamma = cosf(gamma); + + float expM = expf(configuration[4] * gamma); + float rayM = cgamma * cgamma; + float mieM = (1.0f + rayM) / powf((1.0f + configuration[8] * configuration[8] - + 2.0f * configuration[8] * cgamma), + 1.5f); + float zenith = sqrtf(ctheta); + + return (1.0f + configuration[0] * expf(configuration[1] / (ctheta + 0.01f))) * + (configuration[2] + configuration[3] * expM + configuration[5] * rayM + + configuration[6] * mieM + configuration[7] * zenith); +} + +ccl_device float3 sky_radiance_hosek(KernelGlobals kg, + float3 dir, + float sunphi, + float suntheta, + float radiance_x, + float radiance_y, + float radiance_z, + ccl_private float *config_x, + ccl_private float *config_y, + ccl_private float *config_z) +{ + /* convert vector to spherical coordinates */ + float2 spherical = direction_to_spherical(dir); + float theta = spherical.x; + float phi = spherical.y; + + /* 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_F - 0.001f); + + /* compute xyz color space values */ + float x = sky_radiance_internal(config_x, theta, gamma) * radiance_x; + float y = sky_radiance_internal(config_y, theta, gamma) * radiance_y; + float z = sky_radiance_internal(config_z, theta, gamma) * radiance_z; + + /* convert to RGB and adjust strength */ + return xyz_to_rgb(kg, make_float3(x, y, z)) * (M_2PI_F / 683); +} + +/* Nishita improved sky model */ +ccl_device float3 geographical_to_direction(float lat, float lon) +{ + return make_float3(cos(lat) * cos(lon), cos(lat) * sin(lon), sin(lat)); +} + +ccl_device float3 sky_radiance_nishita(KernelGlobals kg, + float3 dir, + ccl_private float *nishita_data, + uint texture_id) +{ + /* 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]; + bool sun_disc = (angular_diameter >= 0.0f); + float3 xyz; + /* convert dir to spherical coordinates */ + float2 direction = direction_to_spherical(dir); + + /* render above the horizon */ + if (dir.z >= 0.0f) { + /* definitions */ + float3 sun_dir = geographical_to_direction(sun_elevation, sun_rotation + M_PI_2_F); + float sun_dir_angle = precise_angle(dir, sun_dir); + float half_angular = angular_diameter / 2.0f; + float dir_elevation = M_PI_2_F - direction.x; + + /* if ray inside sun disc render it, otherwise render sky */ + if (sun_disc && sun_dir_angle < half_angular) { + /* get 2 pixels data */ + float3 pixel_bottom = make_float3(nishita_data[0], nishita_data[1], nishita_data[2]); + float3 pixel_top = make_float3(nishita_data[3], nishita_data[4], nishita_data[5]); + float y; + + /* sun interpolation */ + if (sun_elevation - half_angular > 0.0f) { + if (sun_elevation + half_angular > 0.0f) { + y = ((dir_elevation - sun_elevation) / angular_diameter) + 0.5f; + xyz = interp(pixel_bottom, pixel_top, y) * sun_intensity; + } + } + else { + if (sun_elevation + half_angular > 0.0f) { + y = dir_elevation / (sun_elevation + half_angular); + xyz = interp(pixel_bottom, pixel_top, y) * sun_intensity; + } + } + /* limb darkening, coefficient is 0.6f */ + float limb_darkening = (1.0f - + 0.6f * (1.0f - sqrtf(1.0f - sqr(sun_dir_angle / half_angular)))); + xyz *= limb_darkening; + } + /* sky */ + else { + /* sky interpolation */ + float x = (direction.y + M_PI_F + sun_rotation) / M_2PI_F; + /* more pixels toward horizon compensation */ + float y = safe_sqrtf(dir_elevation / M_PI_2_F); + if (x > 1.0f) { + x -= 1.0f; + } + xyz = float4_to_float3(kernel_tex_image_interp(kg, texture_id, x, y)); + } + } + /* ground */ + else { + if (dir.z < -0.4f) { + xyz = make_float3(0.0f, 0.0f, 0.0f); + } + else { + /* black ground fade */ + float fade = 1.0f + dir.z * 2.5f; + fade = sqr(fade) * fade; + /* interpolation */ + float x = (direction.y + M_PI_F + sun_rotation) / M_2PI_F; + if (x > 1.0f) { + x -= 1.0f; + } + xyz = float4_to_float3(kernel_tex_image_interp(kg, texture_id, x, -0.5)) * fade; + } + } + + /* convert to RGB */ + return xyz_to_rgb(kg, xyz); +} + +ccl_device_noinline int svm_node_tex_sky( + KernelGlobals kg, ccl_private ShaderData *sd, ccl_private float *stack, uint4 node, int offset) +{ + /* Load data */ + uint dir_offset = node.y; + uint out_offset = node.z; + int sky_model = node.w; + + float3 dir = stack_load_float3(stack, dir_offset); + float3 f; + + /* Preetham and Hosek share the same data */ + if (sky_model == 0 || sky_model == 1) { + /* Define variables */ + float sunphi, suntheta, radiance_x, radiance_y, radiance_z; + float config_x[9], config_y[9], config_z[9]; + + float4 data = read_node_float(kg, &offset); + sunphi = data.x; + suntheta = data.y; + radiance_x = data.z; + radiance_y = data.w; + + data = read_node_float(kg, &offset); + radiance_z = data.x; + config_x[0] = data.y; + config_x[1] = data.z; + config_x[2] = data.w; + + data = read_node_float(kg, &offset); + config_x[3] = data.x; + config_x[4] = data.y; + config_x[5] = data.z; + config_x[6] = data.w; + + data = read_node_float(kg, &offset); + config_x[7] = data.x; + config_x[8] = data.y; + config_y[0] = data.z; + config_y[1] = data.w; + + data = read_node_float(kg, &offset); + config_y[2] = data.x; + config_y[3] = data.y; + config_y[4] = data.z; + config_y[5] = data.w; + + data = read_node_float(kg, &offset); + config_y[6] = data.x; + config_y[7] = data.y; + config_y[8] = data.z; + config_z[0] = data.w; + + data = read_node_float(kg, &offset); + config_z[1] = data.x; + config_z[2] = data.y; + config_z[3] = data.z; + config_z[4] = data.w; + + data = read_node_float(kg, &offset); + config_z[5] = data.x; + config_z[6] = data.y; + config_z[7] = data.z; + config_z[8] = data.w; + + /* Compute Sky */ + if (sky_model == 0) { + f = sky_radiance_preetham(kg, + dir, + sunphi, + suntheta, + radiance_x, + radiance_y, + radiance_z, + config_x, + config_y, + config_z); + } + else { + f = sky_radiance_hosek(kg, + dir, + sunphi, + suntheta, + radiance_x, + radiance_y, + radiance_z, + config_x, + config_y, + config_z); + } + } + /* Nishita */ + else { + /* Define variables */ + float nishita_data[10]; + + float4 data = read_node_float(kg, &offset); + nishita_data[0] = data.x; + nishita_data[1] = data.y; + nishita_data[2] = data.z; + nishita_data[3] = data.w; + + data = read_node_float(kg, &offset); + nishita_data[4] = data.x; + nishita_data[5] = data.y; + nishita_data[6] = data.z; + nishita_data[7] = data.w; + + data = read_node_float(kg, &offset); + nishita_data[8] = data.x; + nishita_data[9] = data.y; + uint texture_id = __float_as_uint(data.z); + + /* Compute Sky */ + f = sky_radiance_nishita(kg, dir, nishita_data, texture_id); + } + + stack_store_float3(stack, out_offset, f); + return offset; +} + +CCL_NAMESPACE_END |