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Diffstat (limited to 'source/blender/draw/engines/eevee/shaders/effect_ssr_frag.glsl')
| -rw-r--r-- | source/blender/draw/engines/eevee/shaders/effect_ssr_frag.glsl | 517 |
1 files changed, 517 insertions, 0 deletions
diff --git a/source/blender/draw/engines/eevee/shaders/effect_ssr_frag.glsl b/source/blender/draw/engines/eevee/shaders/effect_ssr_frag.glsl new file mode 100644 index 00000000000..aa88e365d93 --- /dev/null +++ b/source/blender/draw/engines/eevee/shaders/effect_ssr_frag.glsl @@ -0,0 +1,517 @@ + +/* Based on Stochastic Screen Space Reflections + * https://www.ea.com/frostbite/news/stochastic-screen-space-reflections */ + +#ifndef UTIL_TEX +#define UTIL_TEX +uniform sampler2DArray utilTex; +#define texelfetch_noise_tex(coord) texelFetch(utilTex, ivec3(ivec2(coord) % LUT_SIZE, 2.0), 0) +#endif /* UTIL_TEX */ + +#define MAX_MIP 9.0 + +uniform ivec2 halfresOffset; + +ivec2 encode_hit_data(vec2 hit_pos, bool has_hit, bool is_planar) +{ + ivec2 hit_data = ivec2(saturate(hit_pos) * 32767.0); /* 16bit signed int limit */ + hit_data.x *= (is_planar) ? -1 : 1; + hit_data.y *= (has_hit) ? 1 : -1; + return hit_data; +} + +vec2 decode_hit_data(vec2 hit_data, out bool has_hit, out bool is_planar) +{ + is_planar = (hit_data.x < 0); + has_hit = (hit_data.y > 0); + return vec2(abs(hit_data)) / 32767.0; /* 16bit signed int limit */ +} + +#ifdef STEP_RAYTRACE + +uniform sampler2D normalBuffer; +uniform sampler2D specroughBuffer; + +layout(location = 0) out ivec2 hitData; +layout(location = 1) out float pdfData; + +void do_planar_ssr(int index, vec3 V, vec3 N, vec3 T, vec3 B, vec3 planeNormal, vec3 viewPosition, float a2, vec4 rand) +{ + float NH; + vec3 H = sample_ggx(rand.xzw, a2, N, T, B, NH); /* Microfacet normal */ + float pdf = pdf_ggx_reflect(NH, a2); + + vec3 R = reflect(-V, H); + R = reflect(R, planeNormal); + + /* If ray is bad (i.e. going below the plane) regenerate. */ + if (dot(R, planeNormal) > 0.0) { + vec3 H = sample_ggx(rand.xzw * vec3(1.0, -1.0, -1.0), a2, N, T, B, NH); /* Microfacet normal */ + pdf = pdf_ggx_reflect(NH, a2); + + R = reflect(-V, H); + R = reflect(R, planeNormal); + } + + pdfData = min(1024e32, pdf); /* Theoretical limit of 16bit float */ + + /* Since viewspace hit position can land behind the camera in this case, + * we save the reflected view position (visualize it as the hit position + * below the reflection plane). This way it's garanted that the hit will + * be in front of the camera. That let us tag the bad rays with a negative + * sign in the Z component. */ + vec3 hit_pos = raycast(index, viewPosition, R * 1e16, 1e16, rand.y, ssrQuality, a2, false); + + hitData = encode_hit_data(hit_pos.xy, (hit_pos.z > 0.0), true); +} + +void do_ssr(vec3 V, vec3 N, vec3 T, vec3 B, vec3 viewPosition, float a2, vec4 rand) +{ + float NH; + vec3 H = sample_ggx(rand.xzw, a2, N, T, B, NH); /* Microfacet normal */ + float pdf = pdf_ggx_reflect(NH, a2); + + vec3 R = reflect(-V, H); + pdfData = min(1024e32, pdf); /* Theoretical limit of 16bit float */ + + vec3 hit_pos = raycast(-1, viewPosition, R * 1e16, ssrThickness, rand.y, ssrQuality, a2, true); + + hitData = encode_hit_data(hit_pos.xy, (hit_pos.z > 0.0), false); +} + +void main() +{ +#ifdef FULLRES + ivec2 fullres_texel = ivec2(gl_FragCoord.xy); + ivec2 halfres_texel = fullres_texel; +#else + ivec2 fullres_texel = ivec2(gl_FragCoord.xy) * 2 + halfresOffset; + ivec2 halfres_texel = ivec2(gl_FragCoord.xy); +#endif + + float depth = texelFetch(depthBuffer, fullres_texel, 0).r; + + /* Default: not hits. */ + hitData = encode_hit_data(vec2(0.5), false, false); + pdfData = 0.0; + + /* Early out */ + /* We can't do discard because we don't clear the render target. */ + if (depth == 1.0) + return; + + vec2 uvs = vec2(fullres_texel) / vec2(textureSize(depthBuffer, 0)); + + /* Using view space */ + vec3 viewPosition = get_view_space_from_depth(uvs, depth); + vec3 V = viewCameraVec; + vec3 N = normal_decode(texelFetch(normalBuffer, fullres_texel, 0).rg, V); + + /* Retrieve pixel data */ + vec4 speccol_roughness = texelFetch(specroughBuffer, fullres_texel, 0).rgba; + + /* Early out */ + if (dot(speccol_roughness.rgb, vec3(1.0)) == 0.0) + return; + + float roughness = speccol_roughness.a; + float roughnessSquared = max(1e-3, roughness * roughness); + float a2 = roughnessSquared * roughnessSquared; + + /* Early out */ + if (roughness > ssrMaxRoughness + 0.2) + return; + + vec4 rand = texelFetch(utilTex, ivec3(halfres_texel % LUT_SIZE, 2), 0); + + /* Gives *perfect* reflection for very small roughness */ + if (roughness < 0.04) { + rand.xzw *= 0.0; + } + /* Importance sampling bias */ + rand.x = mix(rand.x, 0.0, ssrBrdfBias); + + vec3 worldPosition = transform_point(ViewMatrixInverse, viewPosition); + vec3 wN = transform_direction(ViewMatrixInverse, N); + + vec3 T, B; + make_orthonormal_basis(N, T, B); /* Generate tangent space */ + + /* Planar Reflections */ + for (int i = 0; i < MAX_PLANAR && i < prbNumPlanar; ++i) { + PlanarData pd = planars_data[i]; + + float fade = probe_attenuation_planar(pd, worldPosition, wN, 0.0); + + if (fade > 0.5) { + /* Find view vector / reflection plane intersection. */ + /* TODO optimize, use view space for all. */ + vec3 tracePosition = line_plane_intersect(worldPosition, cameraVec, pd.pl_plane_eq); + tracePosition = transform_point(ViewMatrix, tracePosition); + vec3 planeNormal = transform_direction(ViewMatrix, pd.pl_normal); + + do_planar_ssr(i, V, N, T, B, planeNormal, tracePosition, a2, rand); + return; + } + } + + do_ssr(V, N, T, B, viewPosition, a2, rand); +} + +#else /* STEP_RESOLVE */ + +uniform sampler2D prevColorBuffer; /* previous frame */ +uniform sampler2D normalBuffer; +uniform sampler2D specroughBuffer; + +uniform isampler2D hitBuffer; +uniform sampler2D pdfBuffer; + +uniform int neighborOffset; + +const ivec2 neighbors[32] = ivec2[32]( + ivec2( 0, 0), ivec2( 1, 1), ivec2(-2, 0), ivec2( 0, -2), + ivec2( 0, 0), ivec2( 1, -1), ivec2(-2, 0), ivec2( 0, 2), + ivec2( 0, 0), ivec2(-1, -1), ivec2( 2, 0), ivec2( 0, 2), + ivec2( 0, 0), ivec2(-1, 1), ivec2( 2, 0), ivec2( 0, -2), + + ivec2( 0, 0), ivec2( 2, 2), ivec2(-2, 2), ivec2( 0, -1), + ivec2( 0, 0), ivec2( 2, -2), ivec2(-2, -2), ivec2( 0, 1), + ivec2( 0, 0), ivec2(-2, -2), ivec2(-2, 2), ivec2( 1, 0), + ivec2( 0, 0), ivec2( 2, 2), ivec2( 2, -2), ivec2(-1, 0) +); + +out vec4 fragColor; + +void fallback_cubemap( + vec3 N, vec3 V, vec3 W, vec3 viewPosition, float roughness, float roughnessSquared, inout vec4 spec_accum) +{ + /* Specular probes */ + vec3 spec_dir = get_specular_reflection_dominant_dir(N, V, roughnessSquared); + + vec4 rand = texelfetch_noise_tex(gl_FragCoord.xy); + vec3 bent_normal; +#ifdef SSR_AO + float final_ao = occlusion_compute(N, viewPosition, 1.0, rand, bent_normal); + final_ao = specular_occlusion(dot(N, V), final_ao, roughness); +#else + const float final_ao = 1.0; +#endif + + /* Starts at 1 because 0 is world probe */ + for (int i = 1; i < MAX_PROBE && i < prbNumRenderCube && spec_accum.a < 0.999; ++i) { + CubeData cd = probes_data[i]; + + float fade = probe_attenuation_cube(cd, W); + + if (fade > 0.0) { + vec3 spec = final_ao * probe_evaluate_cube(float(i), cd, W, spec_dir, roughness); + accumulate_light(spec, fade, spec_accum); + } + } + + /* World Specular */ + if (spec_accum.a < 0.999) { + vec3 spec = final_ao * probe_evaluate_world_spec(spec_dir, roughness); + accumulate_light(spec, 1.0, spec_accum); + } +} + +#if 0 /* Finish reprojection with motion vectors */ +vec3 get_motion_vector(vec3 pos) +{ +} + +/* http://bitsquid.blogspot.fr/2017/06/reprojecting-reflections_22.html */ +vec3 find_reflection_incident_point(vec3 cam, vec3 hit, vec3 pos, vec3 N) +{ + float d_cam = point_plane_projection_dist(cam, pos, N); + float d_hit = point_plane_projection_dist(hit, pos, N); + + if (d_hit < d_cam) { + /* Swap */ + float tmp = d_cam; + d_cam = d_hit; + d_hit = tmp; + } + + vec3 proj_cam = cam - (N * d_cam); + vec3 proj_hit = hit - (N * d_hit); + + return (proj_hit - proj_cam) * d_cam / (d_cam + d_hit) + proj_cam; +} +#endif + +float brightness(vec3 c) +{ + return max(max(c.r, c.g), c.b); +} + +vec2 get_reprojected_reflection(vec3 hit, vec3 pos, vec3 N) +{ + /* TODO real reprojection with motion vectors, etc... */ + return project_point(pastViewProjectionMatrix, hit).xy * 0.5 + 0.5; +} + +float get_sample_depth(vec2 hit_co, bool is_planar, float planar_index) +{ + if (is_planar) { + return textureLod(planarDepth, vec3(hit_co, planar_index), 0.0).r; + } + else { + return textureLod(depthBuffer, hit_co, 0.0).r; + } +} + +vec3 get_hit_vector( + vec3 hit_pos, PlanarData pd, vec3 worldPosition, vec3 N, vec3 V, bool is_planar, + inout vec2 hit_co, inout float mask) +{ + vec3 hit_vec; + + if (is_planar) { + /* Reflect back the hit position to have it in non-reflected world space */ + vec3 trace_pos = line_plane_intersect(worldPosition, V, pd.pl_plane_eq); + hit_vec = hit_pos - trace_pos; + hit_vec = reflect(hit_vec, pd.pl_normal); + } + else { + /* Find hit position in previous frame. */ + mask = screen_border_mask(gl_FragCoord.xy / vec2(textureSize(depthBuffer, 0))); + hit_co = get_reprojected_reflection(hit_pos, worldPosition, N); + hit_vec = hit_pos - worldPosition; + } + + mask = min(mask, screen_border_mask(hit_co)); + return hit_vec; +} + +vec3 get_scene_color(vec2 ref_uvs, float mip, float planar_index, bool is_planar) +{ + if (is_planar) { + return textureLod(probePlanars, vec3(ref_uvs, planar_index), min(mip, prbLodPlanarMax)).rgb; + } + else { + return textureLod(prevColorBuffer, ref_uvs, mip).rgb; + } +} + +vec4 get_ssr_samples( + vec4 hit_pdf, ivec4 hit_data[2], + PlanarData pd, float planar_index, vec3 worldPosition, vec3 N, vec3 V, + float roughnessSquared, float cone_tan, vec2 source_uvs, + inout float weight_acc) +{ + bvec4 is_planar, has_hit; + vec4 hit_co[2]; + hit_co[0].xy = decode_hit_data(hit_data[0].xy, has_hit.x, is_planar.x); + hit_co[0].zw = decode_hit_data(hit_data[0].zw, has_hit.y, is_planar.y); + hit_co[1].xy = decode_hit_data(hit_data[1].xy, has_hit.z, is_planar.z); + hit_co[1].zw = decode_hit_data(hit_data[1].zw, has_hit.w, is_planar.w); + + vec4 hit_depth; + hit_depth.x = get_sample_depth(hit_co[0].xy, is_planar.x, planar_index); + hit_depth.y = get_sample_depth(hit_co[0].zw, is_planar.y, planar_index); + hit_depth.z = get_sample_depth(hit_co[1].xy, is_planar.z, planar_index); + hit_depth.w = get_sample_depth(hit_co[1].zw, is_planar.w, planar_index); + + /* Hit position in view space. */ + vec3 hit_view[4]; + hit_view[0] = get_view_space_from_depth(hit_co[0].xy, hit_depth.x); + hit_view[1] = get_view_space_from_depth(hit_co[0].zw, hit_depth.y); + hit_view[2] = get_view_space_from_depth(hit_co[1].xy, hit_depth.z); + hit_view[3] = get_view_space_from_depth(hit_co[1].zw, hit_depth.w); + + vec4 homcoord = vec4(hit_view[0].z, hit_view[1].z, hit_view[2].z, hit_view[3].z); + homcoord = ProjectionMatrix[2][3] * homcoord + ProjectionMatrix[3][3]; + + /* Hit position in world space. */ + vec3 hit_pos[4]; + hit_pos[0] = transform_point(ViewMatrixInverse, hit_view[0]); + hit_pos[1] = transform_point(ViewMatrixInverse, hit_view[1]); + hit_pos[2] = transform_point(ViewMatrixInverse, hit_view[2]); + hit_pos[3] = transform_point(ViewMatrixInverse, hit_view[3]); + + /* Get actual hit vector and hit coordinate (from last frame). */ + vec4 mask = vec4(1.0); + hit_pos[0] = get_hit_vector(hit_pos[0], pd, worldPosition, N, V, is_planar.x, hit_co[0].xy, mask.x); + hit_pos[1] = get_hit_vector(hit_pos[1], pd, worldPosition, N, V, is_planar.y, hit_co[0].zw, mask.y); + hit_pos[2] = get_hit_vector(hit_pos[2], pd, worldPosition, N, V, is_planar.z, hit_co[1].xy, mask.z); + hit_pos[3] = get_hit_vector(hit_pos[3], pd, worldPosition, N, V, is_planar.w, hit_co[1].zw, mask.w); + + vec4 hit_dist; + hit_dist.x = length(hit_pos[0]); + hit_dist.y = length(hit_pos[1]); + hit_dist.z = length(hit_pos[2]); + hit_dist.w = length(hit_pos[3]); + hit_dist = max(vec4(1e-8), hit_dist); + + /* Normalize */ + hit_pos[0] /= hit_dist.x; + hit_pos[1] /= hit_dist.y; + hit_pos[2] /= hit_dist.z; + hit_pos[3] /= hit_dist.w; + + /* Compute cone footprint in screen space. */ + vec4 cone_footprint = hit_dist * cone_tan; + cone_footprint = ssrBrdfBias * 0.5 * cone_footprint * max(ProjectionMatrix[0][0], ProjectionMatrix[1][1]) / homcoord; + + /* Estimate a cone footprint to sample a corresponding mipmap level. */ + vec4 mip = log2(cone_footprint * max_v2(vec2(textureSize(depthBuffer, 0)))); + mip = clamp(mip, 0.0, MAX_MIP); + + /* Correct UVs for mipmaping mis-alignment */ + hit_co[0].xy *= mip_ratio_interp(mip.x); + hit_co[0].zw *= mip_ratio_interp(mip.y); + hit_co[1].xy *= mip_ratio_interp(mip.z); + hit_co[1].zw *= mip_ratio_interp(mip.w); + + /* Slide 54 */ + vec4 bsdf; + bsdf.x = bsdf_ggx(N, hit_pos[0], V, roughnessSquared); + bsdf.y = bsdf_ggx(N, hit_pos[1], V, roughnessSquared); + bsdf.z = bsdf_ggx(N, hit_pos[2], V, roughnessSquared); + bsdf.w = bsdf_ggx(N, hit_pos[3], V, roughnessSquared); + + vec4 weight = step(1e-8, hit_pdf) * bsdf / max(vec4(1e-8), hit_pdf); + + vec3 sample[4]; + sample[0] = get_scene_color(hit_co[0].xy, mip.x, planar_index, is_planar.x); + sample[1] = get_scene_color(hit_co[0].zw, mip.y, planar_index, is_planar.y); + sample[2] = get_scene_color(hit_co[1].xy, mip.z, planar_index, is_planar.z); + sample[3] = get_scene_color(hit_co[1].zw, mip.w, planar_index, is_planar.w); + + /* Clamped brightness. */ + vec4 luma; + luma.x = brightness(sample[0]); + luma.y = brightness(sample[1]); + luma.z = brightness(sample[2]); + luma.w = brightness(sample[3]); + luma = max(vec4(1e-8), luma); + luma = 1.0 - max(vec4(0.0), luma - ssrFireflyFac) / luma; + + sample[0] *= luma.x; + sample[1] *= luma.y; + sample[2] *= luma.z; + sample[3] *= luma.w; + + /* Protection against NaNs in the history buffer. + * This could be removed if some previous pass has already + * sanitized the input. */ + if (any(isnan(sample[0]))) { + sample[0] = vec3(0.0); weight.x = 0.0; + } + if (any(isnan(sample[1]))) { + sample[1] = vec3(0.0); weight.y = 0.0; + } + if (any(isnan(sample[2]))) { + sample[2] = vec3(0.0); weight.z = 0.0; + } + if (any(isnan(sample[3]))) { + sample[3] = vec3(0.0); weight.w = 0.0; + } + + weight_acc += sum(weight); + + /* Do not add light if ray has failed. */ + vec4 accum; + accum = vec4(sample[0], mask.x) * weight.x * float(has_hit.x); + accum += vec4(sample[1], mask.y) * weight.y * float(has_hit.y); + accum += vec4(sample[2], mask.z) * weight.z * float(has_hit.z); + accum += vec4(sample[3], mask.w) * weight.w * float(has_hit.w); + return accum; +} + +void main() +{ + ivec2 fullres_texel = ivec2(gl_FragCoord.xy); +#ifdef FULLRES + ivec2 halfres_texel = fullres_texel; +#else + ivec2 halfres_texel = ivec2(gl_FragCoord.xy / 2.0); +#endif + vec2 uvs = gl_FragCoord.xy / vec2(textureSize(depthBuffer, 0)); + + float depth = textureLod(depthBuffer, uvs, 0.0).r; + + /* Early out */ + if (depth == 1.0) + discard; + + /* Using world space */ + vec3 viewPosition = get_view_space_from_depth(uvs, depth); /* Needed for viewCameraVec */ + vec3 worldPosition = transform_point(ViewMatrixInverse, viewPosition); + vec3 V = cameraVec; + vec3 vN = normal_decode(texelFetch(normalBuffer, fullres_texel, 0).rg, viewCameraVec); + vec3 N = transform_direction(ViewMatrixInverse, vN); + vec4 speccol_roughness = texelFetch(specroughBuffer, fullres_texel, 0).rgba; + + /* Early out */ + if (dot(speccol_roughness.rgb, vec3(1.0)) == 0.0) + discard; + + /* TODO optimize with textureGather */ + /* Doing these fetches early to hide latency. */ + vec4 hit_pdf; + hit_pdf.x = texelFetch(pdfBuffer, halfres_texel + neighbors[0 + neighborOffset], 0).r; + hit_pdf.y = texelFetch(pdfBuffer, halfres_texel + neighbors[1 + neighborOffset], 0).r; + hit_pdf.z = texelFetch(pdfBuffer, halfres_texel + neighbors[2 + neighborOffset], 0).r; + hit_pdf.w = texelFetch(pdfBuffer, halfres_texel + neighbors[3 + neighborOffset], 0).r; + + ivec4 hit_data[2]; + hit_data[0].xy = texelFetch(hitBuffer, halfres_texel + neighbors[0 + neighborOffset], 0).rg; + hit_data[0].zw = texelFetch(hitBuffer, halfres_texel + neighbors[1 + neighborOffset], 0).rg; + hit_data[1].xy = texelFetch(hitBuffer, halfres_texel + neighbors[2 + neighborOffset], 0).rg; + hit_data[1].zw = texelFetch(hitBuffer, halfres_texel + neighbors[3 + neighborOffset], 0).rg; + + /* Find Planar Reflections affecting this pixel */ + PlanarData pd; + float planar_index; + for (int i = 0; i < MAX_PLANAR && i < prbNumPlanar; ++i) { + pd = planars_data[i]; + + float fade = probe_attenuation_planar(pd, worldPosition, N, 0.0); + + if (fade > 0.5) { + planar_index = float(i); + break; + } + } + + float roughness = speccol_roughness.a; + float roughnessSquared = max(1e-3, roughness * roughness); + + vec4 spec_accum = vec4(0.0); + + /* Resolve SSR */ + float cone_cos = cone_cosine(roughnessSquared); + float cone_tan = sqrt(1 - cone_cos * cone_cos) / cone_cos; + cone_tan *= mix(saturate(dot(N, -V) * 2.0), 1.0, roughness); /* Elongation fit */ + + vec2 source_uvs = project_point(pastViewProjectionMatrix, worldPosition).xy * 0.5 + 0.5; + + vec4 ssr_accum = vec4(0.0); + float weight_acc = 0.0; + + if (roughness < ssrMaxRoughness + 0.2) { + ssr_accum += get_ssr_samples(hit_pdf, hit_data, pd, planar_index, worldPosition, N, V, + roughnessSquared, cone_tan, source_uvs, weight_acc); + } + + /* Compute SSR contribution */ + if (weight_acc > 0.0) { + ssr_accum /= weight_acc; + /* fade between 0.5 and 1.0 roughness */ + ssr_accum.a *= smoothstep(ssrMaxRoughness + 0.2, ssrMaxRoughness, roughness); + accumulate_light(ssr_accum.rgb, ssr_accum.a, spec_accum); + } + + /* If SSR contribution is not 1.0, blend with cubemaps */ + if (spec_accum.a < 1.0) { + fallback_cubemap(N, V, worldPosition, viewPosition, roughness, roughnessSquared, spec_accum); + } + + fragColor = vec4(spec_accum.rgb * speccol_roughness.rgb, 1.0); +} + +#endif |