This adds path guiding features into Cycles by integrating Intel's Open Path Guiding Library. It can be enabled in the Sampling > Path Guiding panel in the render properties. This feature helps reduce noise in scenes where finding a path to light is difficult for regular path tracing. The current implementation supports guiding directional sampling decisions on surfaces, when the material contains a least one diffuse component, and in volumes with isotropic and anisotropic Henyey-Greenstein phase functions. On surfaces, the guided sampling decision is proportional to the product of the incident radiance and the normal-oriented cosine lobe and in volumes it is proportional to the product of the incident radiance and the phase function. The incident radiance field of a scene is learned and updated during rendering after each per-frame rendering iteration/progression. At the moment, path guiding is only supported by the CPU backend. Support for GPU backends will be added in future versions of OpenPGL. Ref T92571 Differential Revision: https://developer.blender.org/D15286
89 lines
4.7 KiB
C
89 lines
4.7 KiB
C
/* SPDX-License-Identifier: Apache-2.0
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* Copyright 2011-2022 Blender Foundation */
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/********************************* Shadow Path State **************************/
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KERNEL_STRUCT_BEGIN(shadow_path)
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/* Index of a pixel within the device render buffer. */
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KERNEL_STRUCT_MEMBER(shadow_path, uint32_t, render_pixel_index, KERNEL_FEATURE_PATH_TRACING)
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/* Current sample number. */
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KERNEL_STRUCT_MEMBER(shadow_path, uint32_t, sample, KERNEL_FEATURE_PATH_TRACING)
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/* Random number generator seed. */
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KERNEL_STRUCT_MEMBER(shadow_path, uint32_t, rng_hash, KERNEL_FEATURE_PATH_TRACING)
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/* Random number dimension offset. */
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KERNEL_STRUCT_MEMBER(shadow_path, uint16_t, rng_offset, KERNEL_FEATURE_PATH_TRACING)
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/* Current ray bounce depth. */
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KERNEL_STRUCT_MEMBER(shadow_path, uint16_t, bounce, KERNEL_FEATURE_PATH_TRACING)
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/* Current transparent ray bounce depth. */
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KERNEL_STRUCT_MEMBER(shadow_path, uint16_t, transparent_bounce, KERNEL_FEATURE_PATH_TRACING)
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/* Current diffuse ray bounce depth. */
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KERNEL_STRUCT_MEMBER(shadow_path, uint16_t, diffuse_bounce, KERNEL_FEATURE_PATH_TRACING)
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/* Current glossy ray bounce depth. */
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KERNEL_STRUCT_MEMBER(shadow_path, uint16_t, glossy_bounce, KERNEL_FEATURE_PATH_TRACING)
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/* Current transmission ray bounce depth. */
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KERNEL_STRUCT_MEMBER(shadow_path, uint16_t, transmission_bounce, KERNEL_FEATURE_PATH_TRACING)
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/* DeviceKernel bit indicating queued kernels. */
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KERNEL_STRUCT_MEMBER(shadow_path, uint16_t, queued_kernel, KERNEL_FEATURE_PATH_TRACING)
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/* enum PathRayFlag */
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KERNEL_STRUCT_MEMBER(shadow_path, uint32_t, flag, KERNEL_FEATURE_PATH_TRACING)
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/* Throughput. */
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KERNEL_STRUCT_MEMBER(shadow_path, PackedSpectrum, throughput, KERNEL_FEATURE_PATH_TRACING)
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/* Throughput for shadow pass. */
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KERNEL_STRUCT_MEMBER(shadow_path,
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PackedSpectrum,
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unshadowed_throughput,
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KERNEL_FEATURE_SHADOW_PASS | KERNEL_FEATURE_AO_ADDITIVE)
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/* Ratio of throughput to distinguish diffuse / glossy / transmission render passes. */
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KERNEL_STRUCT_MEMBER(shadow_path, PackedSpectrum, pass_diffuse_weight, KERNEL_FEATURE_LIGHT_PASSES)
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KERNEL_STRUCT_MEMBER(shadow_path, PackedSpectrum, pass_glossy_weight, KERNEL_FEATURE_LIGHT_PASSES)
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/* Number of intersections found by ray-tracing. */
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KERNEL_STRUCT_MEMBER(shadow_path, uint16_t, num_hits, KERNEL_FEATURE_PATH_TRACING)
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/* Light group. */
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KERNEL_STRUCT_MEMBER(shadow_path, uint8_t, lightgroup, KERNEL_FEATURE_PATH_TRACING)
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/* Path guiding. */
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KERNEL_STRUCT_MEMBER(shadow_path, PackedSpectrum, unlit_throughput, KERNEL_FEATURE_PATH_GUIDING)
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#ifdef __PATH_GUIDING__
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KERNEL_STRUCT_MEMBER(shadow_path,
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openpgl::cpp::PathSegment *,
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path_segment,
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KERNEL_FEATURE_PATH_GUIDING)
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#else
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KERNEL_STRUCT_MEMBER(shadow_path, uint64_t, path_segment, KERNEL_FEATURE_PATH_GUIDING)
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#endif
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KERNEL_STRUCT_END(shadow_path)
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/********************************** Shadow Ray *******************************/
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KERNEL_STRUCT_BEGIN(shadow_ray)
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KERNEL_STRUCT_MEMBER(shadow_ray, packed_float3, P, KERNEL_FEATURE_PATH_TRACING)
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KERNEL_STRUCT_MEMBER(shadow_ray, packed_float3, D, KERNEL_FEATURE_PATH_TRACING)
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KERNEL_STRUCT_MEMBER(shadow_ray, float, tmin, KERNEL_FEATURE_PATH_TRACING)
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KERNEL_STRUCT_MEMBER(shadow_ray, float, tmax, KERNEL_FEATURE_PATH_TRACING)
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KERNEL_STRUCT_MEMBER(shadow_ray, float, time, KERNEL_FEATURE_PATH_TRACING)
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KERNEL_STRUCT_MEMBER(shadow_ray, float, dP, KERNEL_FEATURE_PATH_TRACING)
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KERNEL_STRUCT_MEMBER(shadow_ray, int, object, KERNEL_FEATURE_PATH_TRACING)
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KERNEL_STRUCT_END(shadow_ray)
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/*********************** Shadow Intersection result **************************/
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/* Result from scene intersection. */
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KERNEL_STRUCT_BEGIN(shadow_isect)
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KERNEL_STRUCT_ARRAY_MEMBER(shadow_isect, float, t, KERNEL_FEATURE_PATH_TRACING)
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KERNEL_STRUCT_ARRAY_MEMBER(shadow_isect, float, u, KERNEL_FEATURE_PATH_TRACING)
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KERNEL_STRUCT_ARRAY_MEMBER(shadow_isect, float, v, KERNEL_FEATURE_PATH_TRACING)
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KERNEL_STRUCT_ARRAY_MEMBER(shadow_isect, int, prim, KERNEL_FEATURE_PATH_TRACING)
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KERNEL_STRUCT_ARRAY_MEMBER(shadow_isect, int, object, KERNEL_FEATURE_PATH_TRACING)
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KERNEL_STRUCT_ARRAY_MEMBER(shadow_isect, int, type, KERNEL_FEATURE_PATH_TRACING)
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KERNEL_STRUCT_END_ARRAY(shadow_isect,
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INTEGRATOR_SHADOW_ISECT_SIZE_CPU,
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INTEGRATOR_SHADOW_ISECT_SIZE_GPU)
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/**************************** Shadow Volume Stack *****************************/
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KERNEL_STRUCT_BEGIN(shadow_volume_stack)
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KERNEL_STRUCT_ARRAY_MEMBER(shadow_volume_stack, int, object, KERNEL_FEATURE_VOLUME)
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KERNEL_STRUCT_ARRAY_MEMBER(shadow_volume_stack, int, shader, KERNEL_FEATURE_VOLUME)
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KERNEL_STRUCT_END_ARRAY(shadow_volume_stack,
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KERNEL_STRUCT_VOLUME_STACK_SIZE,
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KERNEL_STRUCT_VOLUME_STACK_SIZE)
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