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https://github.com/blender/blender
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cc93b7f5a4
We are running out of bits. Split the original `ShaderDataFlag` into `ShaderRuntimeFlag`, which is determined by closures in the shader and set up during rendering, and `ShaderDataFlag`, which is the same for the whole shader graph and hence determined during shader compilation The size of `ShaderData` did not change due to padding Pull Request: https://projects.blender.org/blender/blender/pulls/161856
64 lines
2.1 KiB
C
64 lines
2.1 KiB
C
/* SPDX-FileCopyrightText: 2011-2024 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/types.h"
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#include "kernel/closure/volume_util.h"
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CCL_NAMESPACE_BEGIN
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/* HENYEY-GREENSTEIN CLOSURE */
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struct HenyeyGreensteinVolume {
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SHADER_CLOSURE_VOLUME_BASE;
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float g;
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};
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static_assert(sizeof(ShaderVolumeClosure) >= sizeof(HenyeyGreensteinVolume),
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"HenyeyGreensteinVolume is too large!");
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ccl_device int volume_henyey_greenstein_setup(ccl_private HenyeyGreensteinVolume *volume)
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{
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volume->type = CLOSURE_VOLUME_HENYEY_GREENSTEIN_ID;
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/* clamp anisotropy to avoid delta function */
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volume->g = signf(volume->g) * min(fabsf(volume->g), 1.0f - 1e-3f);
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return SR_SCATTER;
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}
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ccl_device Spectrum volume_henyey_greenstein_eval(const ccl_private ShaderData *sd,
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const ccl_private ShaderVolumeClosure *svc,
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const float3 wo,
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ccl_private float *pdf)
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{
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const ccl_private HenyeyGreensteinVolume *volume = (const ccl_private HenyeyGreensteinVolume *)
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svc;
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/* note that wi points towards the viewer */
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const float cos_theta = dot(-sd->wi, wo);
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*pdf = phase_henyey_greenstein(cos_theta, volume->g);
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return make_spectrum(*pdf);
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}
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ccl_device int volume_henyey_greenstein_sample(const ccl_private ShaderData *sd,
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const ccl_private ShaderVolumeClosure *svc,
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const float2 rand,
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ccl_private Spectrum *eval,
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ccl_private float3 *wo,
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ccl_private float *pdf)
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{
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const ccl_private HenyeyGreensteinVolume *volume = (const ccl_private HenyeyGreensteinVolume *)
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svc;
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/* note that wi points towards the viewer and so is used negated */
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*wo = phase_henyey_greenstein_sample(-sd->wi, volume->g, rand, pdf);
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*eval = make_spectrum(*pdf); /* perfect importance sampling */
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return LABEL_VOLUME_SCATTER;
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}
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CCL_NAMESPACE_END
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