1284e98ab8
based on concentric disk mapping. Concentric disk mapping was already present, but not used everywhere. Now `sample_cos_hemisphere()`, `sample_uniform_hemisphere()`, and `sample_uniform_cone()` use concentric disk mapping. This changes the noise in many test images. Pull Request: https://projects.blender.org/blender/blender/pulls/109774
83 lines
2.4 KiB
C
83 lines
2.4 KiB
C
/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
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*
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* SPDX-License-Identifier: Apache-2.0 */
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#pragma once
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#include "kernel/sample/mapping.h"
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CCL_NAMESPACE_BEGIN
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/* Light Sample Result */
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typedef struct LightSample {
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float3 P; /* position on light, or direction for distant light */
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float3 Ng; /* normal on light */
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float3 D; /* direction from shading point to light */
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float t; /* distance to light (FLT_MAX for distant light) */
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float u, v; /* parametric coordinate on primitive */
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float pdf; /* pdf for selecting light and point on light */
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float pdf_selection; /* pdf for selecting light */
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float eval_fac; /* intensity multiplier */
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int object; /* object id for triangle/curve lights */
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int prim; /* primitive id for triangle/curve lights */
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int shader; /* shader id */
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int lamp; /* lamp id */
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int group; /* lightgroup */
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LightType type; /* type of light */
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} LightSample;
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/* Utilities */
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ccl_device_inline float3 ellipse_sample(float3 ru, float3 rv, float2 rand)
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{
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const float2 uv = sample_uniform_disk(rand);
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return ru * uv.x + rv * uv.y;
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}
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ccl_device_inline float3 rectangle_sample(float3 ru, float3 rv, float2 rand)
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{
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return ru * (2.0f * rand.x - 1.0f) + rv * (2.0f * rand.y - 1.0f);
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}
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ccl_device float3 disk_light_sample(float3 n, float2 rand)
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{
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float3 ru, rv;
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make_orthonormals(n, &ru, &rv);
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return ellipse_sample(ru, rv, rand);
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}
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ccl_device float lamp_light_pdf(const float3 Ng, const float3 I, float t)
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{
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float cos_pi = dot(Ng, I);
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if (cos_pi <= 0.0f)
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return 0.0f;
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return t * t / cos_pi;
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}
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/* Visibility flag om the light shader. */
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ccl_device_inline bool is_light_shader_visible_to_path(const int shader, const uint32_t path_flag)
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{
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if ((shader & SHADER_EXCLUDE_ANY) == 0) {
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return true;
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}
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if (((shader & SHADER_EXCLUDE_DIFFUSE) && (path_flag & PATH_RAY_DIFFUSE)) ||
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((shader & SHADER_EXCLUDE_GLOSSY) && ((path_flag & (PATH_RAY_GLOSSY | PATH_RAY_REFLECT)) ==
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(PATH_RAY_GLOSSY | PATH_RAY_REFLECT))) ||
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((shader & SHADER_EXCLUDE_TRANSMIT) && (path_flag & PATH_RAY_TRANSMIT)) ||
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((shader & SHADER_EXCLUDE_CAMERA) && (path_flag & PATH_RAY_CAMERA)) ||
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((shader & SHADER_EXCLUDE_SCATTER) && (path_flag & PATH_RAY_VOLUME_SCATTER)))
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{
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return false;
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}
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return true;
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}
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CCL_NAMESPACE_END
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