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Diffstat (limited to 'intern/cycles/kernel/kernel_light_common.h')
| -rw-r--r-- | intern/cycles/kernel/kernel_light_common.h | 227 |
1 files changed, 0 insertions, 227 deletions
diff --git a/intern/cycles/kernel/kernel_light_common.h b/intern/cycles/kernel/kernel_light_common.h deleted file mode 100644 index 9e2b738f376..00000000000 --- a/intern/cycles/kernel/kernel_light_common.h +++ /dev/null @@ -1,227 +0,0 @@ -/* - * Copyright 2011-2020 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 - -#include "kernel_montecarlo.h" - -CCL_NAMESPACE_BEGIN - -/* Area light sampling */ - -/* Uses the following paper: - * - * Carlos Urena et al. - * An Area-Preserving Parametrization for Spherical Rectangles. - * - * https://www.solidangle.com/research/egsr2013_spherical_rectangle.pdf - * - * Note: light_p is modified when sample_coord is true. - */ -ccl_device_inline float rect_light_sample(float3 P, - ccl_private float3 *light_p, - float3 axisu, - float3 axisv, - float randu, - float randv, - bool sample_coord) -{ - /* In our name system we're using P for the center, - * which is o in the paper. - */ - - float3 corner = *light_p - axisu * 0.5f - axisv * 0.5f; - float axisu_len, axisv_len; - /* Compute local reference system R. */ - float3 x = normalize_len(axisu, &axisu_len); - float3 y = normalize_len(axisv, &axisv_len); - float3 z = cross(x, y); - /* Compute rectangle coords in local reference system. */ - float3 dir = corner - P; - float z0 = dot(dir, z); - /* Flip 'z' to make it point against Q. */ - if (z0 > 0.0f) { - z *= -1.0f; - z0 *= -1.0f; - } - float x0 = dot(dir, x); - float y0 = dot(dir, y); - float x1 = x0 + axisu_len; - float y1 = y0 + axisv_len; - /* Compute internal angles (gamma_i). */ - float4 diff = make_float4(x0, y1, x1, y0) - make_float4(x1, y0, x0, y1); - float4 nz = make_float4(y0, x1, y1, x0) * diff; - nz = nz / sqrt(z0 * z0 * diff * diff + nz * nz); - float g0 = safe_acosf(-nz.x * nz.y); - float g1 = safe_acosf(-nz.y * nz.z); - float g2 = safe_acosf(-nz.z * nz.w); - float g3 = safe_acosf(-nz.w * nz.x); - /* Compute predefined constants. */ - float b0 = nz.x; - float b1 = nz.z; - float b0sq = b0 * b0; - float k = M_2PI_F - g2 - g3; - /* Compute solid angle from internal angles. */ - float S = g0 + g1 - k; - - if (sample_coord) { - /* Compute cu. */ - float au = randu * S + k; - float fu = (cosf(au) * b0 - b1) / sinf(au); - float cu = 1.0f / sqrtf(fu * fu + b0sq) * (fu > 0.0f ? 1.0f : -1.0f); - cu = clamp(cu, -1.0f, 1.0f); - /* Compute xu. */ - float xu = -(cu * z0) / max(sqrtf(1.0f - cu * cu), 1e-7f); - xu = clamp(xu, x0, x1); - /* Compute yv. */ - float z0sq = z0 * z0; - float y0sq = y0 * y0; - float y1sq = y1 * y1; - float d = sqrtf(xu * xu + z0sq); - float h0 = y0 / sqrtf(d * d + y0sq); - float h1 = y1 / sqrtf(d * d + y1sq); - float hv = h0 + randv * (h1 - h0), hv2 = hv * hv; - float yv = (hv2 < 1.0f - 1e-6f) ? (hv * d) / sqrtf(1.0f - hv2) : y1; - - /* Transform (xu, yv, z0) to world coords. */ - *light_p = P + xu * x + yv * y + z0 * z; - } - - /* return pdf */ - if (S != 0.0f) - return 1.0f / S; - else - return 0.0f; -} - -ccl_device_inline float3 ellipse_sample(float3 ru, float3 rv, float randu, float randv) -{ - to_unit_disk(&randu, &randv); - return ru * randu + rv * randv; -} - -ccl_device float3 disk_light_sample(float3 v, float randu, float randv) -{ - float3 ru, rv; - - make_orthonormals(v, &ru, &rv); - - return ellipse_sample(ru, rv, randu, randv); -} - -ccl_device float3 distant_light_sample(float3 D, float radius, float randu, float randv) -{ - return normalize(D + disk_light_sample(D, randu, randv) * radius); -} - -ccl_device float3 -sphere_light_sample(float3 P, float3 center, float radius, float randu, float randv) -{ - return disk_light_sample(normalize(P - center), randu, randv) * radius; -} - -ccl_device float spot_light_attenuation(float3 dir, float spot_angle, float spot_smooth, float3 N) -{ - float attenuation = dot(dir, N); - - if (attenuation <= spot_angle) { - attenuation = 0.0f; - } - else { - float t = attenuation - spot_angle; - - if (t < spot_smooth && spot_smooth != 0.0f) - attenuation *= smoothstepf(t / spot_smooth); - } - - return attenuation; -} - -ccl_device float light_spread_attenuation(const float3 D, - const float3 lightNg, - const float tan_spread, - const float normalize_spread) -{ - /* Model a soft-box grid, computing the ratio of light not hidden by the - * slats of the grid at a given angle. (see D10594). */ - const float cos_a = -dot(D, lightNg); - const float sin_a = safe_sqrtf(1.0f - sqr(cos_a)); - const float tan_a = sin_a / cos_a; - return max((1.0f - (tan_spread * tan_a)) * normalize_spread, 0.0f); -} - -/* Compute subset of area light that actually has an influence on the shading point, to - * reduce noise with low spread. */ -ccl_device bool light_spread_clamp_area_light(const float3 P, - const float3 lightNg, - ccl_private float3 *lightP, - ccl_private float3 *axisu, - ccl_private float3 *axisv, - const float tan_spread) -{ - /* Closest point in area light plane and distance to that plane. */ - const float3 closest_P = P - dot(lightNg, P - *lightP) * lightNg; - const float t = len(closest_P - P); - - /* Radius of circle on area light that actually affects the shading point. */ - const float radius = t / tan_spread; - - /* TODO: would be faster to store as normalized vector + length, also in rect_light_sample. */ - float len_u, len_v; - const float3 u = normalize_len(*axisu, &len_u); - const float3 v = normalize_len(*axisv, &len_v); - - /* Local uv coordinates of closest point. */ - const float closest_u = dot(u, closest_P - *lightP); - const float closest_v = dot(v, closest_P - *lightP); - - /* Compute rectangle encompassing the circle that affects the shading point, - * clamped to the bounds of the area light. */ - const float min_u = max(closest_u - radius, -len_u * 0.5f); - const float max_u = min(closest_u + radius, len_u * 0.5f); - const float min_v = max(closest_v - radius, -len_v * 0.5f); - const float max_v = min(closest_v + radius, len_v * 0.5f); - - /* Skip if rectangle is empty. */ - if (min_u >= max_u || min_v >= max_v) { - return false; - } - - /* Compute new area light center position and axes from rectangle in local - * uv coordinates. */ - const float new_center_u = 0.5f * (min_u + max_u); - const float new_center_v = 0.5f * (min_v + max_v); - const float new_len_u = max_u - min_u; - const float new_len_v = max_v - min_v; - - *lightP = *lightP + new_center_u * u + new_center_v * v; - *axisu = u * new_len_u; - *axisv = v * new_len_v; - - return true; -} - -ccl_device float lamp_light_pdf(KernelGlobals kg, const float3 Ng, const float3 I, float t) -{ - float cos_pi = dot(Ng, I); - - if (cos_pi <= 0.0f) - return 0.0f; - - return t * t / cos_pi; -} - -CCL_NAMESPACE_END |