diff --git a/source/blender/draw/CMakeLists.txt b/source/blender/draw/CMakeLists.txt index 720b9a59e95..d68277de2d2 100644 --- a/source/blender/draw/CMakeLists.txt +++ b/source/blender/draw/CMakeLists.txt @@ -155,6 +155,7 @@ set(SRC engines/eevee_next/eevee_shader.cc engines/eevee_next/eevee_shadow.cc engines/eevee_next/eevee_sync.cc + engines/eevee_next/eevee_subsurface.cc engines/eevee_next/eevee_velocity.cc engines/eevee_next/eevee_view.cc engines/eevee_next/eevee_world.cc @@ -296,6 +297,7 @@ set(SRC engines/eevee_next/eevee_shader.hh engines/eevee_next/eevee_shadow.hh engines/eevee_next/eevee_sync.hh + engines/eevee_next/eevee_subsurface.hh engines/eevee_next/eevee_velocity.hh engines/eevee_next/eevee_view.hh engines/eevee_next/eevee_world.hh @@ -504,6 +506,7 @@ set(GLSL_SRC engines/eevee_next/shaders/eevee_shadow_tilemap_init_comp.glsl engines/eevee_next/shaders/eevee_shadow_tilemap_lib.glsl engines/eevee_next/shaders/eevee_spherical_harmonics_lib.glsl + engines/eevee_next/shaders/eevee_subsurface_eval_frag.glsl engines/eevee_next/shaders/eevee_surf_deferred_frag.glsl engines/eevee_next/shaders/eevee_surf_depth_frag.glsl engines/eevee_next/shaders/eevee_surf_forward_frag.glsl diff --git a/source/blender/draw/engines/eevee_next/eevee_defines.hh b/source/blender/draw/engines/eevee_next/eevee_defines.hh index e73d0fbaf17..169f1ed9e61 100644 --- a/source/blender/draw/engines/eevee_next/eevee_defines.hh +++ b/source/blender/draw/engines/eevee_next/eevee_defines.hh @@ -92,11 +92,13 @@ /* Textures. */ /* Used anywhere. (Starts at index 2, since 0 and 1 are used by draw_gpencil) */ #define RBUFS_UTILITY_TEX_SLOT 2 +#define HIZ_TEX_SLOT 3 /* Only during surface shading (forward and deferred eval). */ -#define SHADOW_TILEMAPS_TEX_SLOT 3 -#define SHADOW_ATLAS_TEX_SLOT 4 +#define SHADOW_TILEMAPS_TEX_SLOT 4 +#define SHADOW_ATLAS_TEX_SLOT 5 +#define SSS_TRANSMITTANCE_TEX_SLOT 6 /* Only during shadow rendering. */ -#define SHADOW_RENDER_MAP_SLOT 3 +#define SHADOW_RENDER_MAP_SLOT 4 /* Images. */ #define RBUFS_COLOR_SLOT 0 diff --git a/source/blender/draw/engines/eevee_next/eevee_instance.cc b/source/blender/draw/engines/eevee_next/eevee_instance.cc index d8078003a41..7fe42d425a6 100644 --- a/source/blender/draw/engines/eevee_next/eevee_instance.cc +++ b/source/blender/draw/engines/eevee_next/eevee_instance.cc @@ -206,6 +206,7 @@ void Instance::end_sync() shadows.end_sync(); /** \note: Needs to be before lights. */ lights.end_sync(); sampling.end_sync(); + subsurface.end_sync(); film.end_sync(); cryptomatte.end_sync(); pipelines.end_sync(); diff --git a/source/blender/draw/engines/eevee_next/eevee_instance.hh b/source/blender/draw/engines/eevee_next/eevee_instance.hh index 10758250bc3..466ed28bf64 100644 --- a/source/blender/draw/engines/eevee_next/eevee_instance.hh +++ b/source/blender/draw/engines/eevee_next/eevee_instance.hh @@ -31,6 +31,7 @@ #include "eevee_sampling.hh" #include "eevee_shader.hh" #include "eevee_shadow.hh" +#include "eevee_subsurface.hh" #include "eevee_sync.hh" #include "eevee_view.hh" #include "eevee_world.hh" @@ -49,6 +50,7 @@ class Instance { ShaderModule &shaders; SyncModule sync; MaterialModule materials; + SubsurfaceModule subsurface; PipelineModule pipelines; ShadowModule shadows; LightModule lights; @@ -95,6 +97,7 @@ class Instance { : shaders(*ShaderModule::module_get()), sync(*this), materials(*this), + subsurface(*this), pipelines(*this), shadows(*this), lights(*this), diff --git a/source/blender/draw/engines/eevee_next/eevee_pipeline.cc b/source/blender/draw/engines/eevee_next/eevee_pipeline.cc index 3f575ff1606..6545bcf5a32 100644 --- a/source/blender/draw/engines/eevee_next/eevee_pipeline.cc +++ b/source/blender/draw/engines/eevee_next/eevee_pipeline.cc @@ -142,6 +142,8 @@ void ForwardPipeline::sync() opaque_ps_.bind_image(RBUFS_CRYPTOMATTE_SLOT, &inst_.render_buffers.cryptomatte_tx); /* Textures. */ opaque_ps_.bind_texture(RBUFS_UTILITY_TEX_SLOT, inst_.pipelines.utility_tx); + opaque_ps_.bind_texture(SSS_TRANSMITTANCE_TEX_SLOT, inst_.subsurface.transmittance_tx_get()); + /* Uniform Buffer. */ opaque_ps_.bind_ubo(CAMERA_BUF_SLOT, inst_.camera.ubo_get()); opaque_ps_.bind_ubo(RBUFS_BUF_SLOT, &inst_.render_buffers.data); @@ -169,6 +171,7 @@ void ForwardPipeline::sync() /* Textures. */ sub.bind_texture(RBUFS_UTILITY_TEX_SLOT, inst_.pipelines.utility_tx); + sub.bind_texture(SSS_TRANSMITTANCE_TEX_SLOT, inst_.subsurface.transmittance_tx_get()); /* Uniform Buffer. */ sub.bind_ubo(CAMERA_BUF_SLOT, inst_.camera.ubo_get()); @@ -306,7 +309,7 @@ void DeferredLayer::begin_sync() { gbuffer_ps_.init(); gbuffer_ps_.clear_stencil(0x00u); - gbuffer_ps_.state_stencil(0x01u, 0x01u, 0x01u); + gbuffer_ps_.state_stencil(0xFFu, 0xFFu, 0xFFu); { /* Common resources. */ @@ -343,18 +346,14 @@ void DeferredLayer::begin_sync() void DeferredLayer::end_sync() { - /* Use stencil test to reject pixel not written by this layer. */ - /* WORKAROUND: Stencil write is only here to avoid rasterizer discard. */ - DRWState state = DRW_STATE_WRITE_STENCIL | DRW_STATE_STENCIL_EQUAL; - /* Allow output to combined pass for the last pass. */ - DRWState state_write_color = state | DRW_STATE_WRITE_COLOR | DRW_STATE_BLEND_CUSTOM; - if (closure_bits_ & (CLOSURE_DIFFUSE | CLOSURE_REFLECTION)) { - const bool is_last_eval_pass = true; + const bool is_last_eval_pass = !(closure_bits_ & CLOSURE_SSS); eval_light_ps_.init(); - eval_light_ps_.state_set(is_last_eval_pass ? state_write_color : state); - eval_light_ps_.state_stencil(0x00u, 0x01u, 0xFFu); + /* Use stencil test to reject pixel not written by this layer. */ + eval_light_ps_.state_set(DRW_STATE_WRITE_COLOR | DRW_STATE_STENCIL_NEQUAL | + DRW_STATE_BLEND_CUSTOM); + eval_light_ps_.state_stencil(0x00u, 0x00u, (CLOSURE_DIFFUSE | CLOSURE_REFLECTION)); eval_light_ps_.shader_set(inst_.shaders.static_shader_get(DEFERRED_LIGHT)); eval_light_ps_.bind_image("out_diffuse_light_img", &diffuse_light_tx_); eval_light_ps_.bind_image("out_specular_light_img", &specular_light_tx_); @@ -364,6 +363,8 @@ void DeferredLayer::end_sync() eval_light_ps_.bind_image(RBUFS_COLOR_SLOT, &inst_.render_buffers.rp_color_tx); eval_light_ps_.bind_image(RBUFS_VALUE_SLOT, &inst_.render_buffers.rp_value_tx); eval_light_ps_.bind_texture(RBUFS_UTILITY_TEX_SLOT, inst_.pipelines.utility_tx); + eval_light_ps_.bind_texture(SSS_TRANSMITTANCE_TEX_SLOT, + inst_.subsurface.transmittance_tx_get()); eval_light_ps_.bind_ubo(RBUFS_BUF_SLOT, &inst_.render_buffers.data); inst_.lights.bind_resources(&eval_light_ps_); @@ -391,12 +392,15 @@ PassMain::Sub *DeferredLayer::prepass_add(::Material *blender_mat, PassMain::Sub *DeferredLayer::material_add(::Material *blender_mat, GPUMaterial *gpumat) { - closure_bits_ |= shader_closure_bits_from_flag(gpumat); + eClosureBits closure_bits = shader_closure_bits_from_flag(gpumat); + closure_bits_ |= closure_bits; PassMain::Sub *pass = (blender_mat->blend_flag & MA_BL_CULL_BACKFACE) ? gbuffer_single_sided_ps_ : gbuffer_double_sided_ps_; - return &pass->sub(GPU_material_get_name(gpumat)); + pass = &pass->sub(GPU_material_get_name(gpumat)); + pass->state_stencil(closure_bits, 0xFFu, 0xFFu); + return pass; } void DeferredLayer::render(View &view, @@ -404,7 +408,6 @@ void DeferredLayer::render(View &view, Framebuffer &combined_fb, int2 extent) { - GPU_framebuffer_bind(prepass_fb); inst_.manager->submit(prepass_ps_, view); @@ -424,6 +427,10 @@ void DeferredLayer::render(View &view, inst_.manager->submit(eval_light_ps_, view); + if (closure_bits_ & CLOSURE_SSS) { + inst_.subsurface.render(view, combined_fb, diffuse_light_tx_); + } + diffuse_light_tx_.release(); specular_light_tx_.release(); diff --git a/source/blender/draw/engines/eevee_next/eevee_shader.cc b/source/blender/draw/engines/eevee_next/eevee_shader.cc index 08037c82329..622b330cb03 100644 --- a/source/blender/draw/engines/eevee_next/eevee_shader.cc +++ b/source/blender/draw/engines/eevee_next/eevee_shader.cc @@ -173,6 +173,8 @@ const char *ShaderModule::static_shader_create_info_name_get(eShaderType shader_ return "eevee_shadow_tag_usage_opaque"; case SHADOW_TILEMAP_TAG_USAGE_TRANSPARENT: return "eevee_shadow_tag_usage_transparent"; + case SUBSURFACE_EVAL: + return "eevee_subsurface_eval"; /* To avoid compiler warning about missing case. */ case MAX_SHADER_TYPE: return ""; @@ -256,6 +258,10 @@ void ShaderModule::material_create_info_ammend(GPUMaterial *gpumat, GPUCodegenOu info.additional_info("eevee_cryptomatte_out"); } + if (GPU_material_flag_get(gpumat, GPU_MATFLAG_SUBSURFACE) && pipeline_type == MAT_PIPE_FORWARD) { + info.additional_info("eevee_transmittance_data"); + } + if (GPU_material_flag_get(gpumat, GPU_MATFLAG_BARYCENTRIC)) { switch (geometry_type) { case MAT_GEOM_MESH: diff --git a/source/blender/draw/engines/eevee_next/eevee_shader.hh b/source/blender/draw/engines/eevee_next/eevee_shader.hh index 9f8b84196a7..e9748be501a 100644 --- a/source/blender/draw/engines/eevee_next/eevee_shader.hh +++ b/source/blender/draw/engines/eevee_next/eevee_shader.hh @@ -81,6 +81,8 @@ enum eShaderType { SHADOW_TILEMAP_TAG_USAGE_OPAQUE, SHADOW_TILEMAP_TAG_USAGE_TRANSPARENT, + SUBSURFACE_EVAL, + MAX_SHADER_TYPE, }; diff --git a/source/blender/draw/engines/eevee_next/eevee_shader_shared.hh b/source/blender/draw/engines/eevee_next/eevee_shader_shared.hh index 7f449ee471b..40d724d582a 100644 --- a/source/blender/draw/engines/eevee_next/eevee_shader_shared.hh +++ b/source/blender/draw/engines/eevee_next/eevee_shader_shared.hh @@ -977,6 +977,7 @@ using ShadowPageCacheBuf = draw::StorageArrayBuffer; using ShadowTileMapClipBuf = draw::StorageArrayBuffer; using ShadowTileDataBuf = draw::StorageArrayBuffer; +using SubsurfaceDataBuf = draw::UniformBuffer; using VelocityGeometryBuf = draw::StorageArrayBuffer; using VelocityIndexBuf = draw::StorageArrayBuffer; using VelocityObjectBuf = draw::StorageArrayBuffer; diff --git a/source/blender/draw/engines/eevee_next/eevee_subsurface.cc b/source/blender/draw/engines/eevee_next/eevee_subsurface.cc new file mode 100644 index 00000000000..58e606c3b8e --- /dev/null +++ b/source/blender/draw/engines/eevee_next/eevee_subsurface.cc @@ -0,0 +1,222 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later + * Copyright 2021 Blender Foundation. + */ + +/** \file + * \ingroup eevee + * + */ + +#include "BLI_vector.hh" + +#include "eevee_instance.hh" +#include "eevee_subsurface.hh" + +#include + +namespace blender::eevee { + +/* -------------------------------------------------------------------- */ +/** \name Subsurface + * + * \{ */ + +void SubsurfaceModule::end_sync() +{ + data_.jitter_threshold = inst_.scene->eevee.sss_jitter_threshold; + if (data_.sample_len != inst_.scene->eevee.sss_samples) { + /* Convert sample count from old implementation which was using a separable filter. */ + /* TODO(fclem) better remapping. */ + // data_.sample_len = square_f(1 + 2 * inst_.scene->eevee.sss_samples); + data_.sample_len = 55; + } + + if (!transmittance_tx_.is_valid()) { + precompute_transmittance_profile(); + } + + precompute_samples_location(); + + data_.push_update(); + + subsurface_ps_.init(); + subsurface_ps_.state_set(DRW_STATE_WRITE_COLOR | DRW_STATE_STENCIL_EQUAL | + DRW_STATE_BLEND_ADD_FULL); + subsurface_ps_.state_stencil(0x00u, 0xFFu, CLOSURE_SSS); + subsurface_ps_.shader_set(inst_.shaders.static_shader_get(SUBSURFACE_EVAL)); + inst_.subsurface.bind_resources(&subsurface_ps_); + inst_.hiz_buffer.bind_resources(&subsurface_ps_); + subsurface_ps_.bind_texture("radiance_tx", &diffuse_light_tx_); + subsurface_ps_.bind_texture("gbuffer_closure_tx", &inst_.gbuffer.closure_tx); + subsurface_ps_.bind_texture("gbuffer_color_tx", &inst_.gbuffer.color_tx); + subsurface_ps_.bind_ubo(RBUFS_BUF_SLOT, &inst_.render_buffers.data); + subsurface_ps_.bind_image(RBUFS_COLOR_SLOT, &inst_.render_buffers.rp_color_tx); + /** NOTE: Not used in the shader, but we bind it to avoid debug warnings. */ + subsurface_ps_.bind_image(RBUFS_VALUE_SLOT, &inst_.render_buffers.rp_value_tx); + + subsurface_ps_.barrier(GPU_BARRIER_TEXTURE_FETCH); + subsurface_ps_.draw_procedural(GPU_PRIM_TRIS, 1, 3); +} + +void SubsurfaceModule::render(View &view, Framebuffer &fb, Texture &diffuse_light_tx) +{ + fb.bind(); + diffuse_light_tx_ = *&diffuse_light_tx; + inst_.manager->submit(subsurface_ps_, view); +} + +void SubsurfaceModule::precompute_samples_location() +{ + /* Precompute sample position with white albedo. */ + float d = burley_setup(1.0f, 1.0f); + + float rand_u = inst_.sampling.rng_get(SAMPLING_SSS_U); + float rand_v = inst_.sampling.rng_get(SAMPLING_SSS_V); + + double golden_angle = M_PI * (3.0 - sqrt(5.0)); + for (auto i : IndexRange(data_.sample_len)) { + float theta = golden_angle * i + M_PI * 2.0f * rand_u; + /* Scale using rand_v in order to keep first sample always at center. */ + float x = (1.0f + (rand_v / data_.sample_len)) * (i / (float)data_.sample_len); + float r = burley_sample(d, x); + data_.samples[i].x = cosf(theta) * r; + data_.samples[i].y = sinf(theta) * r; + data_.samples[i].z = 1.0f / burley_pdf(d, r); + } +} + +void SubsurfaceModule::precompute_transmittance_profile() +{ + Vector profile(SSS_TRANSMIT_LUT_SIZE); + + /* Precompute sample position with white albedo. */ + float radius = 1.0f; + float d = burley_setup(radius, 1.0f); + + /* For each distance d we compute the radiance incoming from an hypothetical parallel plane. */ + for (auto i : IndexRange(SSS_TRANSMIT_LUT_SIZE)) { + /* Distance from the lit surface plane. + * Compute to a larger maximum distance to have a smoother falloff for all channels. */ + float lut_radius = SSS_TRANSMIT_LUT_RADIUS * radius; + float distance = lut_radius * (i + 1e-5f) / profile.size(); + /* Compute radius of the footprint on the hypothetical plane. */ + float r_fp = sqrtf(square_f(lut_radius) - square_f(distance)); + + profile[i] = 0.0f; + float area_accum = 0.0f; + for (auto j : IndexRange(SSS_TRANSMIT_LUT_STEP_RES)) { + /* Compute distance to the "shading" point through the medium. */ + float r = (r_fp * (j + 0.5f)) / SSS_TRANSMIT_LUT_STEP_RES; + float r_prev = (r_fp * (j + 0.0f)) / SSS_TRANSMIT_LUT_STEP_RES; + float r_next = (r_fp * (j + 1.0f)) / SSS_TRANSMIT_LUT_STEP_RES; + r = hypotf(r, distance); + float R = burley_eval(d, r); + /* Since the profile and configuration are radially symmetrical we + * can just evaluate it once and weight it accordingly */ + float disk_area = square_f(r_next) - square_f(r_prev); + + profile[i] += R * disk_area; + area_accum += disk_area; + } + /* Normalize over the disk. */ + profile[i] /= area_accum; + } + + /** NOTE: There's something very wrong here. + * This should be a small remap, + * but current profile range goes from 0.0399098 to 0.0026898. */ + + /* Make a smooth gradient from 1 to 0. */ + float range = profile.first() - profile.last(); + float offset = profile.last(); + for (float &value : profile) { + value = (value - offset) / range; + /** HACK: Remap the curve to better fit Cycles values. */ + value = std::pow(value, 1.6f); + } + profile.first() = 1; + profile.last() = 0; + + transmittance_tx_.ensure_1d( + GPU_R16F, profile.size(), GPU_TEXTURE_USAGE_SHADER_READ, profile.data()); +} + +/** \} */ + +/* -------------------------------------------------------------------- */ +/** \name Christensen-Burley SSS model + * + * Based on: "Approximate Reflectance Profiles for Efficient Subsurface Scattering" + * by Per Christensen + * https://graphics.pixar.com/library/ApproxBSSRDF/approxbssrdfslides.pdf + * \{ */ + +float SubsurfaceModule::burley_setup(float radius, float albedo) +{ + float A = albedo; + /* Diffuse surface transmission, equation (6). */ + float s = 1.9f - A + 3.5f * square_f(A - 0.8f); + /* Mean free path length adapted to fit ancient Cubic and Gaussian models. */ + float l = 0.25 * M_1_PI * radius; + + return l / s; +} + +float SubsurfaceModule::burley_sample(float d, float x_rand) +{ + x_rand *= SSS_BURLEY_TRUNCATE_CDF; + + const float tolerance = 1e-6; + const int max_iteration_count = 10; + /* Do initial guess based on manual curve fitting, this allows us to reduce + * number of iterations to maximum 4 across the [0..1] range. We keep maximum + * number of iteration higher just to be sure we didn't miss root in some + * corner case. + */ + float r; + if (x_rand <= 0.9) { + r = exp(x_rand * x_rand * 2.4) - 1.0; + } + else { + /* TODO(sergey): Some nicer curve fit is possible here. */ + r = 15.0; + } + /* Solve against scaled radius. */ + for (int i = 0; i < max_iteration_count; i++) { + float exp_r_3 = exp(-r / 3.0); + float exp_r = exp_r_3 * exp_r_3 * exp_r_3; + float f = 1.0 - 0.25 * exp_r - 0.75 * exp_r_3 - x_rand; + float f_ = 0.25 * exp_r + 0.25 * exp_r_3; + + if (abs(f) < tolerance || f_ == 0.0) { + break; + } + + r = r - f / f_; + if (r < 0.0) { + r = 0.0; + } + } + + return r * d; +} + +float SubsurfaceModule::burley_eval(float d, float r) +{ + if (r >= SSS_BURLEY_TRUNCATE * d) { + return 0.0; + } + /* Slide 33. */ + float exp_r_3_d = expf(-r / (3.0f * d)); + float exp_r_d = exp_r_3_d * exp_r_3_d * exp_r_3_d; + return (exp_r_d + exp_r_3_d) / (8.0f * (float)M_PI * d); +} + +float SubsurfaceModule::burley_pdf(float d, float r) +{ + return burley_eval(d, r) / SSS_BURLEY_TRUNCATE_CDF; +} + +/** \} */ + +} // namespace blender::eevee diff --git a/source/blender/draw/engines/eevee_next/eevee_subsurface.hh b/source/blender/draw/engines/eevee_next/eevee_subsurface.hh new file mode 100644 index 00000000000..433aa60c616 --- /dev/null +++ b/source/blender/draw/engines/eevee_next/eevee_subsurface.hh @@ -0,0 +1,81 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later + * Copyright 2021 Blender Foundation. + */ + +/** \file + * \ingroup eevee + * + * Postprocess diffuse radiance output from the diffuse evaluation pass to mimic subsurface + * transmission. + * + * This implementation follows the technique described in the siggraph presentation: + * "Efficient screen space subsurface scattering Siggraph 2018" + * by Evgenii Golubev + * + * But, instead of having all the precomputed weights for all three color primaries, + * we precompute a weight profile texture to be able to support per pixel AND per channel radius. + */ + +#pragma once + +#include "eevee_shader.hh" +#include "eevee_shader_shared.hh" + +namespace blender::eevee { + +/* -------------------------------------------------------------------- */ +/** \name Subsurface + * + * \{ */ + +class Instance; + +struct SubsurfaceModule { + private: + Instance &inst_; + /** Contains samples locations. */ + SubsurfaceDataBuf data_; + /** Contains translucence profile for a single color channel. */ + Texture transmittance_tx_; + /** Scene diffuse irradiance. Pointer binded at sync time, set at render time. */ + GPUTexture *diffuse_light_tx_; + /** Subsurface eval pass. Runs after the deferred pass. */ + PassSimple subsurface_ps_ = {"Subsurface"}; + + public: + SubsurfaceModule(Instance &inst) : inst_(inst) + { + /* Force first update. */ + data_.sample_len = -1; + }; + + ~SubsurfaceModule(){}; + + void end_sync(); + + void render(View &view, Framebuffer &fb, Texture &diffuse_light_tx); + + template void bind_resources(draw::detail::PassBase *pass) + { + pass->bind_ubo("sss_buf", data_); + } + + GPUTexture **transmittance_tx_get(void) + { + return &transmittance_tx_; + } + + private: + void precompute_samples_location(); + void precompute_transmittance_profile(); + + /** Christensen-Burley implementation. */ + static float burley_setup(float radius, float albedo); + static float burley_sample(float d, float x_rand); + static float burley_eval(float d, float r); + static float burley_pdf(float d, float r); +}; + +/** \} */ + +} // namespace blender::eevee diff --git a/source/blender/draw/engines/eevee_next/shaders/eevee_deferred_light_frag.glsl b/source/blender/draw/engines/eevee_next/shaders/eevee_deferred_light_frag.glsl index 9653fe630bf..d8383e8f701 100644 --- a/source/blender/draw/engines/eevee_next/shaders/eevee_deferred_light_frag.glsl +++ b/source/blender/draw/engines/eevee_next/shaders/eevee_deferred_light_frag.glsl @@ -42,11 +42,11 @@ void main() * produces a complete diffuse light buffer that will be correctly convolved by the SSSS. * The refraction pixels will just set the diffuse radiance to 0. */ } - else if (false /* TODO */) { + else if (textureSize(gbuffer_closure_tx, 0).z >= 3) { vec4 gbuffer_2_packed = texelFetch(gbuffer_closure_tx, ivec3(texel, 2), 0); diffuse_data.sss_radius = gbuffer_sss_radii_unpack(gbuffer_2_packed.xyz); diffuse_data.sss_id = gbuffer_object_id_unorm16_unpack(gbuffer_2_packed.w); - thickness = gbuffer_thickness_pack(gbuffer_1_packed.z); + thickness = gbuffer_thickness_unpack(gbuffer_1_packed.z); } vec3 diffuse_light = vec3(0.0); @@ -64,51 +64,41 @@ void main() reflection_light, shadow); - if (is_last_eval_pass) { - /* Apply color and output lighting to render-passes. */ - vec4 color_0_packed = texelFetch(gbuffer_color_tx, ivec3(texel, 0), 0); - vec4 color_1_packed = texelFetch(gbuffer_color_tx, ivec3(texel, 1), 0); - - reflection_data.color = gbuffer_color_unpack(color_0_packed); - diffuse_data.color = gbuffer_color_unpack(color_1_packed); - - if (is_refraction) { - diffuse_data.color = vec3(0.0); - } - - /* Light passes. */ - if (rp_buf.diffuse_light_id >= 0) { - imageStore(rp_color_img, ivec3(texel, rp_buf.diffuse_light_id), vec4(diffuse_light, 1.0)); - } - if (rp_buf.specular_light_id >= 0) { - imageStore( - rp_color_img, ivec3(texel, rp_buf.specular_light_id), vec4(reflection_light, 1.0)); - } - if (rp_buf.shadow_id >= 0) { - imageStore(rp_value_img, ivec3(texel, rp_buf.shadow_id), vec4(shadow)); - } - /* TODO: AO. */ - - diffuse_light *= diffuse_data.color; - reflection_light *= reflection_data.color; - /* Add radiance to combined pass. */ - out_radiance = vec4(diffuse_light + reflection_light, 0.0); - out_transmittance = vec4(1.0); - } - else { - /* Store lighting for next deferred pass. */ - + if (!is_last_eval_pass) { /* Output diffuse light along with object ID for sub-surface screen space processing. */ vec4 diffuse_radiance; diffuse_radiance.xyz = diffuse_light; diffuse_radiance.w = gbuffer_object_id_f16_pack(diffuse_data.sss_id); imageStore(out_diffuse_light_img, texel, diffuse_radiance); - imageStore(out_specular_light_img, texel, vec4(reflection_light, 0.0)); - - /* Final radiance will be amended by the last pass. - * This should do nothing as color write should be disabled in this case. */ - out_radiance = vec4(0.0); - out_transmittance = vec4(0.0); } + + /* Apply color and output lighting to render-passes. */ + vec4 color_0_packed = texelFetch(gbuffer_color_tx, ivec3(texel, 0), 0); + vec4 color_1_packed = texelFetch(gbuffer_color_tx, ivec3(texel, 1), 0); + + reflection_data.color = gbuffer_color_unpack(color_0_packed); + diffuse_data.color = gbuffer_color_unpack(color_1_packed); + + if (is_refraction) { + diffuse_data.color = vec3(0.0); + } + + /* Light passes. */ + if (rp_buf.diffuse_light_id >= 0) { + imageStore(rp_color_img, ivec3(texel, rp_buf.diffuse_light_id), vec4(diffuse_light, 1.0)); + } + if (rp_buf.specular_light_id >= 0) { + imageStore(rp_color_img, ivec3(texel, rp_buf.specular_light_id), vec4(reflection_light, 1.0)); + } + if (rp_buf.shadow_id >= 0) { + imageStore(rp_value_img, ivec3(texel, rp_buf.shadow_id), vec4(shadow)); + } + /* TODO: AO. */ + + diffuse_light *= diffuse_data.color; + reflection_light *= reflection_data.color; + /* Add radiance to combined pass. */ + out_radiance = vec4(diffuse_light + reflection_light, 0.0); + out_transmittance = vec4(1.0); } diff --git a/source/blender/draw/engines/eevee_next/shaders/eevee_gbuffer_lib.glsl b/source/blender/draw/engines/eevee_next/shaders/eevee_gbuffer_lib.glsl index 2147c68de83..32edcd62a7c 100644 --- a/source/blender/draw/engines/eevee_next/shaders/eevee_gbuffer_lib.glsl +++ b/source/blender/draw/engines/eevee_next/shaders/eevee_gbuffer_lib.glsl @@ -10,7 +10,10 @@ vec2 gbuffer_normal_pack(vec3 N) { N /= length_manhattan(N); - N.xy = (N.z >= 0.0) ? N.xy : ((1.0 - abs(N.yx)) * sign(N.xy)); + vec2 _sign = sign(N.xy); + _sign.x = _sign.x == 0.0 ? 1.0 : _sign.x; + _sign.y = _sign.y == 0.0 ? 1.0 : _sign.y; + N.xy = (N.z >= 0.0) ? N.xy : ((1.0 - abs(N.yx)) * _sign); N.xy = N.xy * 0.5 + 0.5; return N.xy; } @@ -32,7 +35,7 @@ float gbuffer_ior_pack(float ior) float gbuffer_ior_unpack(float ior_packed) { - return (ior_packed > 0.5) ? (-1.0 / (ior_packed * 2.0 + 2.0)) : (2.0 * ior_packed); + return (ior_packed > 0.5) ? (0.5 / (1.0 - ior_packed)) : (2.0 * ior_packed); } float gbuffer_thickness_pack(float thickness) diff --git a/source/blender/draw/engines/eevee_next/shaders/eevee_light_eval_lib.glsl b/source/blender/draw/engines/eevee_next/shaders/eevee_light_eval_lib.glsl index d530f28c04c..919ed643508 100644 --- a/source/blender/draw/engines/eevee_next/shaders/eevee_light_eval_lib.glsl +++ b/source/blender/draw/engines/eevee_next/shaders/eevee_light_eval_lib.glsl @@ -47,7 +47,7 @@ void light_eval_ex(ClosureDiffuse diffuse, #ifdef SSS_TRANSMITTANCE /* Transmittance evaluation first to use initial visibility without shadow. */ if (diffuse.sss_id != 0u && light.diffuse_power > 0.0) { - float delta = max(thickness, samp.occluder_delta + samp.bias); + float delta = max(thickness, -(samp.occluder_delta + samp.bias)); vec3 intensity = visibility * light.transmit_power * light_translucent(sss_transmittance_tx, diff --git a/source/blender/draw/engines/eevee_next/shaders/eevee_subsurface_eval_frag.glsl b/source/blender/draw/engines/eevee_next/shaders/eevee_subsurface_eval_frag.glsl new file mode 100644 index 00000000000..e716ac68cfb --- /dev/null +++ b/source/blender/draw/engines/eevee_next/shaders/eevee_subsurface_eval_frag.glsl @@ -0,0 +1,146 @@ + +/** + * Postprocess diffuse radiance output from the diffuse evaluation pass to mimic subsurface + * transmission. + * + * This implementation follows the technique described in the siggraph presentation: + * "Efficient screen space subsurface scattering Siggraph 2018" + * by Evgenii Golubev + * + * But, instead of having all the precomputed weights for all three color primaries, + * we precompute a weight profile texture to be able to support per pixel AND per channel radius. + **/ + +#pragma BLENDER_REQUIRE(gpu_shader_codegen_lib.glsl) +#pragma BLENDER_REQUIRE(eevee_gbuffer_lib.glsl) +#pragma BLENDER_REQUIRE(common_view_lib.glsl) +#pragma BLENDER_REQUIRE(common_math_geom_lib.glsl) +#pragma BLENDER_REQUIRE(eevee_sampling_lib.glsl) + +vec3 burley_setup(vec3 radius, vec3 albedo) +{ + /* Scale albedo because we can have HDR value caused by BSDF sampling. */ + vec3 A = albedo / max(1e-6, max_v3(albedo)); + /* Diffuse surface transmission, equation (6). */ + vec3 s = 1.9 - A + 3.5 * sqr(A - 0.8); + /* Mean free path length adapted to fit ancient Cubic and Gaussian models. */ + vec3 l = 0.25 * M_1_PI * radius; + + return l / s; +} + +vec3 burley_eval(vec3 d, float r) +{ + /* Slide 33. */ + vec3 exp_r_3_d = exp(-r / (3.0 * d)); + vec3 exp_r_d = exp_r_3_d * exp_r_3_d * exp_r_3_d; + /** NOTE: + * - Surface albedo is applied at the end. + * - This is normalized diffuse model, so the equation is multiplied + * by 2*pi, which also matches cdf(). + */ + return (exp_r_d + exp_r_3_d) / (4.0 * d); +} + +void main(void) +{ + vec2 center_uv = uvcoordsvar.xy; + ivec2 texel = ivec2(gl_FragCoord.xy); + + float gbuffer_depth = texelFetch(hiz_tx, texel, 0).r; + vec3 vP = get_view_space_from_depth(center_uv, gbuffer_depth); + + vec4 color_1_packed = texelFetch(gbuffer_color_tx, ivec3(texel, 1), 0); + vec4 gbuffer_2_packed = texelFetch(gbuffer_closure_tx, ivec3(texel, 2), 0); + + ClosureDiffuse diffuse; + diffuse.sss_radius = gbuffer_sss_radii_unpack(gbuffer_2_packed.xyz); + diffuse.sss_id = gbuffer_object_id_unorm16_unpack(gbuffer_2_packed.w); + diffuse.color = gbuffer_color_unpack(color_1_packed); + + if (diffuse.sss_id == 0u) { + /* Normal diffuse is already in combined pass. */ + /* Refraction also go into this case. */ + out_combined = vec4(0.0); + return; + } + + float max_radius = max_v3(diffuse.sss_radius); + + float homcoord = ProjectionMatrix[2][3] * vP.z + ProjectionMatrix[3][3]; + vec2 sample_scale = vec2(ProjectionMatrix[0][0], ProjectionMatrix[1][1]) * + (0.5 * max_radius / homcoord); + + float pixel_footprint = sample_scale.x * textureSize(hiz_tx, 0).x; + if (pixel_footprint <= 1.0) { + /* Early out. */ + out_combined = vec4(0.0); + return; + } + + diffuse.sss_radius = max(vec3(1e-4), diffuse.sss_radius / max_radius) * max_radius; + vec3 d = burley_setup(diffuse.sss_radius, diffuse.color); + + /* Do not rotate too much to avoid too much cache misses. */ + float golden_angle = M_PI * (3.0 - sqrt(5.0)); + float theta = interlieved_gradient_noise(gl_FragCoord.xy, 0, 0.0) * golden_angle; + float cos_theta = cos(theta); + float sin_theta = sqrt(1.0 - sqr(cos_theta)); + mat2 rot = mat2(cos_theta, sin_theta, -sin_theta, cos_theta); + + mat2 scale = mat2(sample_scale.x, 0.0, 0.0, sample_scale.y); + mat2 sample_space = scale * rot; + + vec3 accum_weight = vec3(0.0); + vec3 accum = vec3(0.0); + + /* TODO/OPTI(fclem) Make separate sample set for lower radius. */ + + for (int i = 0; i < sss_buf.sample_len; i++) { + vec2 sample_uv = center_uv + sample_space * sss_buf.samples[i].xy; + float pdf_inv = sss_buf.samples[i].z; + + float sample_depth = textureLod(hiz_tx, sample_uv * hiz_buf.uv_scale, 0.0).r; + vec3 sample_vP = get_view_space_from_depth(sample_uv, sample_depth); + + vec4 sample_data = texture(radiance_tx, sample_uv); + vec3 sample_radiance = sample_data.rgb; + uint sample_sss_id = uint(sample_data.a); + + if (sample_sss_id != diffuse.sss_id) { + continue; + } + + /* Discard out of bounds samples. */ + if (any(lessThan(sample_uv, vec2(0.0))) || any(greaterThan(sample_uv, vec2(1.0)))) { + continue; + } + + /* Slide 34. */ + float r = distance(sample_vP, vP); + vec3 weight = burley_eval(d, r) * pdf_inv; + + accum += sample_radiance * weight; + accum_weight += weight; + } + /* Normalize the sum (slide 34). */ + accum /= accum_weight; + + if (rp_buf.diffuse_light_id >= 0) { + imageStore(rp_color_img, ivec3(texel, rp_buf.diffuse_light_id), vec4(accum, 1.0)); + } + + /* This pass uses additive blending. + * Subtract the surface diffuse radiance so it's not added twice. */ + accum -= texelFetch(radiance_tx, texel, 0).rgb; + + /* Apply surface color on final radiance. */ + accum *= diffuse.color; + + /* Debug, detect NaNs. */ + if (any(isnan(accum))) { + accum = vec3(1.0, 0.0, 1.0); + } + + out_combined = vec4(accum, 0.0); +} diff --git a/source/blender/draw/engines/eevee_next/shaders/eevee_surf_deferred_frag.glsl b/source/blender/draw/engines/eevee_next/shaders/eevee_surf_deferred_frag.glsl index b7fdca6374c..bf64bec8604 100644 --- a/source/blender/draw/engines/eevee_next/shaders/eevee_surf_deferred_frag.glsl +++ b/source/blender/draw/engines/eevee_next/shaders/eevee_surf_deferred_frag.glsl @@ -124,7 +124,7 @@ void main() /* SubSurface Scattering. */ vec4 closure; closure.xyz = gbuffer_sss_radii_pack(g_diffuse_data.sss_radius); - closure.w = gbuffer_object_id_unorm16_pack(g_diffuse_data.sss_id); + closure.w = gbuffer_object_id_unorm16_pack(g_diffuse_data.sss_id > 0 ? uint(resource_id) : 0); imageStore(out_gbuff_closure_img, ivec3(out_texel, 2), closure); } diff --git a/source/blender/draw/engines/eevee_next/shaders/eevee_surf_forward_frag.glsl b/source/blender/draw/engines/eevee_next/shaders/eevee_surf_forward_frag.glsl index 49764e5219d..c58a943a6f4 100644 --- a/source/blender/draw/engines/eevee_next/shaders/eevee_surf_forward_frag.glsl +++ b/source/blender/draw/engines/eevee_next/shaders/eevee_surf_forward_frag.glsl @@ -63,6 +63,8 @@ void main() g_holdout = saturate(g_holdout); + float thickness = nodetree_thickness(); + vec3 diffuse_light = vec3(0.0); vec3 reflection_light = vec3(0.0); vec3 refraction_light = vec3(0.0); @@ -76,7 +78,7 @@ void main() g_data.Ng, cameraVec(g_data.P), vP_z, - 0.01 /* TODO(fclem) thickness. */, + thickness, diffuse_light, reflection_light, shadow); diff --git a/source/blender/draw/engines/eevee_next/shaders/infos/eevee_deferred_info.hh b/source/blender/draw/engines/eevee_next/shaders/infos/eevee_deferred_info.hh index ba4f149f0b7..cccb62679dd 100644 --- a/source/blender/draw/engines/eevee_next/shaders/infos/eevee_deferred_info.hh +++ b/source/blender/draw/engines/eevee_next/shaders/infos/eevee_deferred_info.hh @@ -39,6 +39,7 @@ GPU_SHADER_CREATE_INFO(eevee_deferred_light) "eevee_light_data", "eevee_shadow_data", "eevee_deferred_base", + "eevee_transmittance_data", "eevee_hiz_data", "eevee_render_pass_out", "draw_view", diff --git a/source/blender/draw/engines/eevee_next/shaders/infos/eevee_hiz_info.hh b/source/blender/draw/engines/eevee_next/shaders/infos/eevee_hiz_info.hh index 7bf87d8744b..cac3574d1f9 100644 --- a/source/blender/draw/engines/eevee_next/shaders/infos/eevee_hiz_info.hh +++ b/source/blender/draw/engines/eevee_next/shaders/infos/eevee_hiz_info.hh @@ -6,7 +6,7 @@ #include "gpu_shader_create_info.hh" GPU_SHADER_CREATE_INFO(eevee_hiz_data) - .sampler(15, ImageType::FLOAT_2D, "hiz_tx") + .sampler(HIZ_TEX_SLOT, ImageType::FLOAT_2D, "hiz_tx") .uniform_buf(5, "HiZData", "hiz_buf"); GPU_SHADER_CREATE_INFO(eevee_hiz_update) diff --git a/source/blender/draw/engines/eevee_next/shaders/infos/eevee_subsurface_info.hh b/source/blender/draw/engines/eevee_next/shaders/infos/eevee_subsurface_info.hh new file mode 100644 index 00000000000..c9d36a85744 --- /dev/null +++ b/source/blender/draw/engines/eevee_next/shaders/infos/eevee_subsurface_info.hh @@ -0,0 +1,21 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ + +#include "eevee_defines.hh" +#include "gpu_shader_create_info.hh" + +GPU_SHADER_CREATE_INFO(eevee_transmittance_data) + .define("SSS_TRANSMITTANCE") + .sampler(SSS_TRANSMITTANCE_TEX_SLOT, ImageType::FLOAT_1D, "sss_transmittance_tx"); + +GPU_SHADER_CREATE_INFO(eevee_subsurface_eval) + .do_static_compilation(true) + .additional_info("eevee_shared", "eevee_render_pass_out") + .uniform_buf(1, "SubsurfaceData", "sss_buf") + .sampler(0, ImageType::FLOAT_2D_ARRAY, "gbuffer_closure_tx") + .sampler(1, ImageType::FLOAT_2D_ARRAY, "gbuffer_color_tx") + .sampler(2, ImageType::FLOAT_2D, "radiance_tx") + .early_fragment_test(true) + .fragment_out(0, Type::VEC4, "out_combined") + .fragment_source("eevee_subsurface_eval_frag.glsl") + /* TODO(fclem) Output to diffuse pass without feedback loop. */ + .additional_info("draw_fullscreen", "draw_view", "eevee_hiz_data"); diff --git a/source/blender/gpu/CMakeLists.txt b/source/blender/gpu/CMakeLists.txt index 4eaaada535a..fa979510b20 100644 --- a/source/blender/gpu/CMakeLists.txt +++ b/source/blender/gpu/CMakeLists.txt @@ -652,6 +652,7 @@ set(SRC_SHADER_CREATE_INFOS ../draw/engines/eevee_next/shaders/infos/eevee_material_info.hh ../draw/engines/eevee_next/shaders/infos/eevee_motion_blur_info.hh ../draw/engines/eevee_next/shaders/infos/eevee_shadow_info.hh + ../draw/engines/eevee_next/shaders/infos/eevee_subsurface_info.hh ../draw/engines/eevee_next/shaders/infos/eevee_velocity_info.hh ../draw/engines/gpencil/shaders/infos/gpencil_info.hh ../draw/engines/gpencil/shaders/infos/gpencil_vfx_info.hh