/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// // Copyright (c) 2016, Intel Corporation // Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated // documentation files (the "Software"), to deal in the Software without restriction, including without limitation // the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to // permit persons to whom the Software is furnished to do so, subject to the following conditions: // The above copyright notice and this permission notice shall be included in all copies or substantial portions of // the Software. // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO // THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, // TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE // SOFTWARE. /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// // File changes (yyyy-mm-dd) // 2016-09-07: filip.strugar@intel.com: first commit // 2020-12-05: clayjohn: convert to Vulkan and Godot /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// #[compute] #version 450 #VERSION_DEFINES #define INTELSSAO_MAIN_DISK_SAMPLE_COUNT (32) const vec4 sample_pattern[INTELSSAO_MAIN_DISK_SAMPLE_COUNT] = { vec4(0.78488064, 0.56661671, 1.500000, -0.126083), vec4(0.26022232, -0.29575172, 1.500000, -1.064030), vec4(0.10459357, 0.08372527, 1.110000, -2.730563), vec4(-0.68286800, 0.04963045, 1.090000, -0.498827), vec4(-0.13570161, -0.64190155, 1.250000, -0.532765), vec4(-0.26193795, -0.08205118, 0.670000, -1.783245), vec4(-0.61177456, 0.66664219, 0.710000, -0.044234), vec4(0.43675563, 0.25119025, 0.610000, -1.167283), vec4(0.07884444, 0.86618668, 0.640000, -0.459002), vec4(-0.12790935, -0.29869005, 0.600000, -1.729424), vec4(-0.04031125, 0.02413622, 0.600000, -4.792042), vec4(0.16201244, -0.52851415, 0.790000, -1.067055), vec4(-0.70991218, 0.47301072, 0.640000, -0.335236), vec4(0.03277707, -0.22349690, 0.600000, -1.982384), vec4(0.68921727, 0.36800742, 0.630000, -0.266718), vec4(0.29251814, 0.37775412, 0.610000, -1.422520), vec4(-0.12224089, 0.96582592, 0.600000, -0.426142), vec4(0.11071457, -0.16131058, 0.600000, -2.165947), vec4(0.46562141, -0.59747696, 0.600000, -0.189760), vec4(-0.51548797, 0.11804193, 0.600000, -1.246800), vec4(0.89141309, -0.42090443, 0.600000, 0.028192), vec4(-0.32402530, -0.01591529, 0.600000, -1.543018), vec4(0.60771245, 0.41635221, 0.600000, -0.605411), vec4(0.02379565, -0.08239821, 0.600000, -3.809046), vec4(0.48951152, -0.23657045, 0.600000, -1.189011), vec4(-0.17611565, -0.81696892, 0.600000, -0.513724), vec4(-0.33930185, -0.20732205, 0.600000, -1.698047), vec4(-0.91974425, 0.05403209, 0.600000, 0.062246), vec4(-0.15064627, -0.14949332, 0.600000, -1.896062), vec4(0.53180975, -0.35210401, 0.600000, -0.758838), vec4(0.41487166, 0.81442589, 0.600000, -0.505648), vec4(-0.24106961, -0.32721516, 0.600000, -1.665244) }; // these values can be changed (up to SSAO_MAX_TAPS) with no changes required elsewhere; values for 4th and 5th preset are ignored but array needed to avoid compilation errors // the actual number of texture samples is two times this value (each "tap" has two symmetrical depth texture samples) const int num_taps[5] = { 3, 5, 12, 0, 0 }; #define SSAO_TILT_SAMPLES_ENABLE_AT_QUALITY_PRESET (99) // to disable simply set to 99 or similar #define SSAO_TILT_SAMPLES_AMOUNT (0.4) // #define SSAO_HALOING_REDUCTION_ENABLE_AT_QUALITY_PRESET (1) // to disable simply set to 99 or similar #define SSAO_HALOING_REDUCTION_AMOUNT (0.6) // values from 0.0 - 1.0, 1.0 means max weighting (will cause artifacts, 0.8 is more reasonable) // #define SSAO_NORMAL_BASED_EDGES_ENABLE_AT_QUALITY_PRESET (2) // to disable simply set to 99 or similar #define SSAO_NORMAL_BASED_EDGES_DOT_THRESHOLD (0.5) // use 0-0.1 for super-sharp normal-based edges // #define SSAO_DETAIL_AO_ENABLE_AT_QUALITY_PRESET (1) // whether to use detail; to disable simply set to 99 or similar // // WARNING: The MIP generation on the C++ side will be enabled on quality preset 2 regardless of // this value, so if changing here, change the C++ side too. #define SSAO_DEPTH_MIPS_ENABLE_AT_QUALITY_PRESET (2) #define SSAO_DEPTH_MIPS_GLOBAL_OFFSET (-4.3) // best noise/quality/performance tradeoff, found empirically // // WARNING: The edge handling is hard-coded to 'disabled' on quality level 0, and enabled above, // on the C++ side; while toggling it here will work for testing purposes, it will not yield // performance gains (or correct results). #define SSAO_DEPTH_BASED_EDGES_ENABLE_AT_QUALITY_PRESET (1) // #define SSAO_REDUCE_RADIUS_NEAR_SCREEN_BORDER_ENABLE_AT_QUALITY_PRESET (1) #define SSAO_MAX_TAPS 32 #define SSAO_ADAPTIVE_TAP_BASE_COUNT 5 #define SSAO_ADAPTIVE_TAP_FLEXIBLE_COUNT (SSAO_MAX_TAPS - SSAO_ADAPTIVE_TAP_BASE_COUNT) #define SSAO_DEPTH_MIP_LEVELS 4 layout(local_size_x = 8, local_size_y = 8, local_size_z = 1) in; layout(set = 0, binding = 0) uniform sampler2DArray source_depth_mipmaps; layout(rgba8, set = 0, binding = 1) uniform restrict readonly image2D source_normal; layout(set = 0, binding = 2) uniform Constants { //get into a lower set vec4 rotation_matrices[20]; } constants; #ifdef ADAPTIVE layout(rg8, set = 1, binding = 0) uniform restrict readonly image2DArray source_ssao; layout(set = 1, binding = 1) uniform sampler2D source_importance; layout(set = 1, binding = 2, std430) buffer Counter { uint sum; } counter; #endif layout(rg8, set = 2, binding = 0) uniform restrict writeonly image2D dest_image; // This push_constant is full - 128 bytes - if you need to add more data, consider adding to the uniform buffer instead layout(push_constant, std430) uniform Params { ivec2 screen_size; int pass; int quality; vec2 half_screen_pixel_size; int size_multiplier; float detail_intensity; vec2 NDC_to_view_mul; vec2 NDC_to_view_add; vec2 pad2; vec2 half_screen_pixel_size_x025; float radius; float intensity; float shadow_power; float shadow_clamp; float fade_out_mul; float fade_out_add; float horizon_angle_threshold; float inv_radius_near_limit; bool is_orthogonal; float neg_inv_radius; float load_counter_avg_div; float adaptive_sample_limit; ivec2 pass_coord_offset; vec2 pass_uv_offset; } params; // packing/unpacking for edges; 2 bits per edge mean 4 gradient values (0, 0.33, 0.66, 1) for smoother transitions! float pack_edges(vec4 p_edgesLRTB) { p_edgesLRTB = round(clamp(p_edgesLRTB, 0.0, 1.0) * 3.05); return dot(p_edgesLRTB, vec4(64.0 / 255.0, 16.0 / 255.0, 4.0 / 255.0, 1.0 / 255.0)); } vec3 NDC_to_view_space(vec2 p_pos, float p_viewspace_depth) { if (params.is_orthogonal) { return vec3((params.NDC_to_view_mul * p_pos.xy + params.NDC_to_view_add), p_viewspace_depth); } else { return vec3((params.NDC_to_view_mul * p_pos.xy + params.NDC_to_view_add) * p_viewspace_depth, p_viewspace_depth); } } // calculate effect radius and fit our screen sampling pattern inside it void calculate_radius_parameters(const float p_pix_center_length, const vec2 p_pixel_size_at_center, out float r_lookup_radius, out float r_radius, out float r_fallof_sq) { r_radius = params.radius; // when too close, on-screen sampling disk will grow beyond screen size; limit this to avoid closeup temporal artifacts const float too_close_limit = clamp(p_pix_center_length * params.inv_radius_near_limit, 0.0, 1.0) * 0.8 + 0.2; r_radius *= too_close_limit; // 0.85 is to reduce the radius to allow for more samples on a slope to still stay within influence r_lookup_radius = (0.85 * r_radius) / p_pixel_size_at_center.x; // used to calculate falloff (both for AO samples and per-sample weights) r_fallof_sq = -1.0 / (r_radius * r_radius); } vec4 calculate_edges(const float p_center_z, const float p_left_z, const float p_right_z, const float p_top_z, const float p_bottom_z) { // slope-sensitive depth-based edge detection vec4 edgesLRTB = vec4(p_left_z, p_right_z, p_top_z, p_bottom_z) - p_center_z; vec4 edgesLRTB_slope_adjusted = edgesLRTB + edgesLRTB.yxwz; edgesLRTB = min(abs(edgesLRTB), abs(edgesLRTB_slope_adjusted)); return clamp((1.3 - edgesLRTB / (p_center_z * 0.040)), 0.0, 1.0); } vec3 load_normal(ivec2 p_pos) { vec3 encoded_normal = normalize(imageLoad(source_normal, p_pos).xyz * 2.0 - 1.0); encoded_normal.z = -encoded_normal.z; return encoded_normal; } vec3 load_normal(ivec2 p_pos, ivec2 p_offset) { vec3 encoded_normal = normalize(imageLoad(source_normal, p_pos + p_offset).xyz * 2.0 - 1.0); encoded_normal.z = -encoded_normal.z; return encoded_normal; } // all vectors in viewspace float calculate_pixel_obscurance(vec3 p_pixel_normal, vec3 p_hit_delta, float p_fallof_sq) { float length_sq = dot(p_hit_delta, p_hit_delta); float NdotD = dot(p_pixel_normal, p_hit_delta) / sqrt(length_sq); float falloff_mult = max(0.0, length_sq * p_fallof_sq + 1.0); return max(0, NdotD - params.horizon_angle_threshold) * falloff_mult; } void SSAO_tap_inner(const int p_quality_level, inout float r_obscurance_sum, inout float r_weight_sum, const vec2 p_sampling_uv, const float p_mip_level, const vec3 p_pix_center_pos, vec3 p_pixel_normal, const float p_fallof_sq, const float p_weight_mod) { // get depth at sample float viewspace_sample_z = textureLod(source_depth_mipmaps, vec3(p_sampling_uv, params.pass), p_mip_level).x; // convert to viewspace vec3 hit_pos = NDC_to_view_space(p_sampling_uv.xy, viewspace_sample_z).xyz; vec3 hit_delta = hit_pos - p_pix_center_pos; float obscurance = calculate_pixel_obscurance(p_pixel_normal, hit_delta, p_fallof_sq); float weight = 1.0; if (p_quality_level >= SSAO_HALOING_REDUCTION_ENABLE_AT_QUALITY_PRESET) { float reduct = max(0, -hit_delta.z); reduct = clamp(reduct * params.neg_inv_radius + 2.0, 0.0, 1.0); weight = SSAO_HALOING_REDUCTION_AMOUNT * reduct + (1.0 - SSAO_HALOING_REDUCTION_AMOUNT); } weight *= p_weight_mod; r_obscurance_sum += obscurance * weight; r_weight_sum += weight; } void SSAOTap(const int p_quality_level, inout float r_obscurance_sum, inout float r_weight_sum, const int p_tap_index, const mat2 p_rot_scale, const vec3 p_pix_center_pos, vec3 p_pixel_normal, const vec2 p_normalized_screen_pos, const float p_mip_offset, const float p_fallof_sq, float p_weight_mod, vec2 p_norm_xy, float p_norm_xy_length) { vec2 sample_offset; float sample_pow_2_len; // patterns { vec4 new_sample = sample_pattern[p_tap_index]; sample_offset = new_sample.xy * p_rot_scale; sample_pow_2_len = new_sample.w; // precalculated, same as: sample_pow_2_len = log2( length( new_sample.xy ) ); p_weight_mod *= new_sample.z; } // snap to pixel center (more correct obscurance math, avoids artifacts) sample_offset = round(sample_offset); // calculate MIP based on the sample distance from the center, similar to as described // in http://graphics.cs.williams.edu/papers/SAOHPG12/. float mip_level = (p_quality_level < SSAO_DEPTH_MIPS_ENABLE_AT_QUALITY_PRESET) ? (0) : (sample_pow_2_len + p_mip_offset); vec2 sampling_uv = sample_offset * params.half_screen_pixel_size + p_normalized_screen_pos; SSAO_tap_inner(p_quality_level, r_obscurance_sum, r_weight_sum, sampling_uv, mip_level, p_pix_center_pos, p_pixel_normal, p_fallof_sq, p_weight_mod); // for the second tap, just use the mirrored offset vec2 sample_offset_mirrored_uv = -sample_offset; // tilt the second set of samples so that the disk is effectively rotated by the normal // effective at removing one set of artifacts, but too expensive for lower quality settings if (p_quality_level >= SSAO_TILT_SAMPLES_ENABLE_AT_QUALITY_PRESET) { float dot_norm = dot(sample_offset_mirrored_uv, p_norm_xy); sample_offset_mirrored_uv -= dot_norm * p_norm_xy_length * p_norm_xy; sample_offset_mirrored_uv = round(sample_offset_mirrored_uv); } // snap to pixel center (more correct obscurance math, avoids artifacts) vec2 sampling_mirrored_uv = sample_offset_mirrored_uv * params.half_screen_pixel_size + p_normalized_screen_pos; SSAO_tap_inner(p_quality_level, r_obscurance_sum, r_weight_sum, sampling_mirrored_uv, mip_level, p_pix_center_pos, p_pixel_normal, p_fallof_sq, p_weight_mod); } void generate_SSAO_shadows_internal(out float r_shadow_term, out vec4 r_edges, out float r_weight, const vec2 p_pos, int p_quality_level, bool p_adaptive_base) { vec2 pos_rounded = trunc(p_pos); uvec2 upos = uvec2(pos_rounded); const int number_of_taps = (p_adaptive_base) ? (SSAO_ADAPTIVE_TAP_BASE_COUNT) : (num_taps[p_quality_level]); float pix_z, pix_left_z, pix_top_z, pix_right_z, pix_bottom_z; vec4 valuesUL = textureGather(source_depth_mipmaps, vec3(pos_rounded * params.half_screen_pixel_size, params.pass)); vec4 valuesBR = textureGather(source_depth_mipmaps, vec3((pos_rounded + vec2(1.0)) * params.half_screen_pixel_size, params.pass)); // get this pixel's viewspace depth pix_z = valuesUL.y; // get left right top bottom neighboring pixels for edge detection (gets compiled out on quality_level == 0) pix_left_z = valuesUL.x; pix_top_z = valuesUL.z; pix_right_z = valuesBR.z; pix_bottom_z = valuesBR.x; vec2 normalized_screen_pos = pos_rounded * params.half_screen_pixel_size + params.half_screen_pixel_size_x025; vec3 pix_center_pos = NDC_to_view_space(normalized_screen_pos, pix_z); // Load this pixel's viewspace normal uvec2 full_res_coord = upos * 2 * params.size_multiplier + params.pass_coord_offset.xy; vec3 pixel_normal = load_normal(ivec2(full_res_coord)); const vec2 pixel_size_at_center = NDC_to_view_space(normalized_screen_pos.xy + params.half_screen_pixel_size, pix_center_pos.z).xy - pix_center_pos.xy; float pixel_lookup_radius; float fallof_sq; // calculate effect radius and fit our screen sampling pattern inside it float viewspace_radius; calculate_radius_parameters(length(pix_center_pos), pixel_size_at_center, pixel_lookup_radius, viewspace_radius, fallof_sq); // calculate samples rotation/scaling mat2 rot_scale_matrix; uint pseudo_random_index; { vec4 rotation_scale; // reduce effect radius near the screen edges slightly; ideally, one would render a larger depth buffer (5% on each side) instead if (!p_adaptive_base && (p_quality_level >= SSAO_REDUCE_RADIUS_NEAR_SCREEN_BORDER_ENABLE_AT_QUALITY_PRESET)) { float near_screen_border = min(min(normalized_screen_pos.x, 1.0 - normalized_screen_pos.x), min(normalized_screen_pos.y, 1.0 - normalized_screen_pos.y)); near_screen_border = clamp(10.0 * near_screen_border + 0.6, 0.0, 1.0); pixel_lookup_radius *= near_screen_border; } // load & update pseudo-random rotation matrix pseudo_random_index = uint(pos_rounded.y * 2 + pos_rounded.x) % 5; rotation_scale = constants.rotation_matrices[params.pass * 5 + pseudo_random_index]; rot_scale_matrix = mat2(rotation_scale.x * pixel_lookup_radius, rotation_scale.y * pixel_lookup_radius, rotation_scale.z * pixel_lookup_radius, rotation_scale.w * pixel_lookup_radius); } // the main obscurance & sample weight storage float obscurance_sum = 0.0; float weight_sum = 0.0; // edge mask for between this and left/right/top/bottom neighbor pixels - not used in quality level 0 so initialize to "no edge" (1 is no edge, 0 is edge) vec4 edgesLRTB = vec4(1.0, 1.0, 1.0, 1.0); // Move center pixel slightly towards camera to avoid imprecision artifacts due to using of 16bit depth buffer. pix_center_pos *= 0.99; if (!p_adaptive_base && (p_quality_level >= SSAO_DEPTH_BASED_EDGES_ENABLE_AT_QUALITY_PRESET)) { edgesLRTB = calculate_edges(pix_z, pix_left_z, pix_right_z, pix_top_z, pix_bottom_z); } // adds a more high definition sharp effect, which gets blurred out (reuses left/right/top/bottom samples that we used for edge detection) if (!p_adaptive_base && (p_quality_level >= SSAO_DETAIL_AO_ENABLE_AT_QUALITY_PRESET)) { // disable in case of quality level 4 (reference) if (p_quality_level != 4) { //approximate neighboring pixels positions (actually just deltas or "positions - pix_center_pos" ) vec3 normalized_viewspace_dir = vec3(pix_center_pos.xy / pix_center_pos.zz, 1.0); vec3 pixel_left_delta = vec3(-pixel_size_at_center.x, 0.0, 0.0) + normalized_viewspace_dir * (pix_left_z - pix_center_pos.z); vec3 pixel_right_delta = vec3(+pixel_size_at_center.x, 0.0, 0.0) + normalized_viewspace_dir * (pix_right_z - pix_center_pos.z); vec3 pixel_top_delta = vec3(0.0, -pixel_size_at_center.y, 0.0) + normalized_viewspace_dir * (pix_top_z - pix_center_pos.z); vec3 pixel_bottom_delta = vec3(0.0, +pixel_size_at_center.y, 0.0) + normalized_viewspace_dir * (pix_bottom_z - pix_center_pos.z); const float range_reduction = 4.0f; // this is to avoid various artifacts const float modified_fallof_sq = range_reduction * fallof_sq; vec4 additional_obscurance; additional_obscurance.x = calculate_pixel_obscurance(pixel_normal, pixel_left_delta, modified_fallof_sq); additional_obscurance.y = calculate_pixel_obscurance(pixel_normal, pixel_right_delta, modified_fallof_sq); additional_obscurance.z = calculate_pixel_obscurance(pixel_normal, pixel_top_delta, modified_fallof_sq); additional_obscurance.w = calculate_pixel_obscurance(pixel_normal, pixel_bottom_delta, modified_fallof_sq); obscurance_sum += params.detail_intensity * dot(additional_obscurance, edgesLRTB); } } // Sharp normals also create edges - but this adds to the cost as well if (!p_adaptive_base && (p_quality_level >= SSAO_NORMAL_BASED_EDGES_ENABLE_AT_QUALITY_PRESET)) { vec3 neighbour_normal_left = load_normal(ivec2(full_res_coord), ivec2(-2, 0)); vec3 neighbour_normal_right = load_normal(ivec2(full_res_coord), ivec2(2, 0)); vec3 neighbour_normal_top = load_normal(ivec2(full_res_coord), ivec2(0, -2)); vec3 neighbour_normal_bottom = load_normal(ivec2(full_res_coord), ivec2(0, 2)); const float dot_threshold = SSAO_NORMAL_BASED_EDGES_DOT_THRESHOLD; vec4 normal_edgesLRTB; normal_edgesLRTB.x = clamp((dot(pixel_normal, neighbour_normal_left) + dot_threshold), 0.0, 1.0); normal_edgesLRTB.y = clamp((dot(pixel_normal, neighbour_normal_right) + dot_threshold), 0.0, 1.0); normal_edgesLRTB.z = clamp((dot(pixel_normal, neighbour_normal_top) + dot_threshold), 0.0, 1.0); normal_edgesLRTB.w = clamp((dot(pixel_normal, neighbour_normal_bottom) + dot_threshold), 0.0, 1.0); edgesLRTB *= normal_edgesLRTB; } const float global_mip_offset = SSAO_DEPTH_MIPS_GLOBAL_OFFSET; float mip_offset = (p_quality_level < SSAO_DEPTH_MIPS_ENABLE_AT_QUALITY_PRESET) ? (0) : (log2(pixel_lookup_radius) + global_mip_offset); // Used to tilt the second set of samples so that the disk is effectively rotated by the normal // effective at removing one set of artifacts, but too expensive for lower quality settings vec2 norm_xy = vec2(pixel_normal.x, pixel_normal.y); float norm_xy_length = length(norm_xy); norm_xy /= vec2(norm_xy_length, -norm_xy_length); norm_xy_length *= SSAO_TILT_SAMPLES_AMOUNT; // standard, non-adaptive approach if ((p_quality_level != 3) || p_adaptive_base) { for (int i = 0; i < number_of_taps; i++) { SSAOTap(p_quality_level, obscurance_sum, weight_sum, i, rot_scale_matrix, pix_center_pos, pixel_normal, normalized_screen_pos, mip_offset, fallof_sq, 1.0, norm_xy, norm_xy_length); } } #ifdef ADAPTIVE else { // add new ones if needed vec2 full_res_uv = normalized_screen_pos + params.pass_uv_offset.xy; float importance = textureLod(source_importance, full_res_uv, 0.0).x; // this is to normalize SSAO_DETAIL_AO_AMOUNT across all pixel regardless of importance obscurance_sum *= (SSAO_ADAPTIVE_TAP_BASE_COUNT / float(SSAO_MAX_TAPS)) + (importance * SSAO_ADAPTIVE_TAP_FLEXIBLE_COUNT / float(SSAO_MAX_TAPS)); // load existing base values vec2 base_values = imageLoad(source_ssao, ivec3(upos, params.pass)).xy; weight_sum += base_values.y * float(SSAO_ADAPTIVE_TAP_BASE_COUNT * 4.0); obscurance_sum += (base_values.x) * weight_sum; // increase importance around edges float edge_count = dot(1.0 - edgesLRTB, vec4(1.0, 1.0, 1.0, 1.0)); float avg_total_importance = float(counter.sum) * params.load_counter_avg_div; float importance_limiter = clamp(params.adaptive_sample_limit / avg_total_importance, 0.0, 1.0); importance *= importance_limiter; float additional_sample_count = SSAO_ADAPTIVE_TAP_FLEXIBLE_COUNT * importance; const float blend_range = 3.0; const float blend_range_inv = 1.0 / blend_range; additional_sample_count += 0.5; uint additional_samples = uint(additional_sample_count); uint additional_samples_to = min(SSAO_MAX_TAPS, additional_samples + SSAO_ADAPTIVE_TAP_BASE_COUNT); for (uint i = SSAO_ADAPTIVE_TAP_BASE_COUNT; i < additional_samples_to; i++) { additional_sample_count -= 1.0f; float weight_mod = clamp(additional_sample_count * blend_range_inv, 0.0, 1.0); SSAOTap(p_quality_level, obscurance_sum, weight_sum, int(i), rot_scale_matrix, pix_center_pos, pixel_normal, normalized_screen_pos, mip_offset, fallof_sq, weight_mod, norm_xy, norm_xy_length); } } #endif // early out for adaptive base - just output weight (used for the next pass) if (p_adaptive_base) { float obscurance = obscurance_sum / weight_sum; r_shadow_term = obscurance; r_edges = vec4(0.0); r_weight = weight_sum; return; } // calculate weighted average float obscurance = obscurance_sum / weight_sum; // calculate fadeout (1 close, gradient, 0 far) float fade_out = clamp(pix_center_pos.z * params.fade_out_mul + params.fade_out_add, 0.0, 1.0); // Reduce the SSAO shadowing if we're on the edge to remove artifacts on edges (we don't care for the lower quality one) if (!p_adaptive_base && (p_quality_level >= SSAO_DEPTH_BASED_EDGES_ENABLE_AT_QUALITY_PRESET)) { // when there's more than 2 opposite edges, start fading out the occlusion to reduce aliasing artifacts float edge_fadeout_factor = clamp((1.0 - edgesLRTB.x - edgesLRTB.y) * 0.35, 0.0, 1.0) + clamp((1.0 - edgesLRTB.z - edgesLRTB.w) * 0.35, 0.0, 1.0); fade_out *= clamp(1.0 - edge_fadeout_factor, 0.0, 1.0); } // strength obscurance = params.intensity * obscurance; // clamp obscurance = min(obscurance, params.shadow_clamp); // fadeout obscurance *= fade_out; // conceptually switch to occlusion with the meaning being visibility (grows with visibility, occlusion == 1 implies full visibility), // to be in line with what is more commonly used. float occlusion = 1.0 - obscurance; // modify the gradient // note: this cannot be moved to a later pass because of loss of precision after storing in the render target occlusion = pow(clamp(occlusion, 0.0, 1.0), params.shadow_power); // outputs! r_shadow_term = occlusion; // Our final 'occlusion' term (0 means fully occluded, 1 means fully lit) r_edges = edgesLRTB; // These are used to prevent blurring across edges, 1 means no edge, 0 means edge, 0.5 means half way there, etc. r_weight = weight_sum; } void main() { float out_shadow_term; float out_weight; vec4 out_edges; ivec2 ssC = ivec2(gl_GlobalInvocationID.xy); if (any(greaterThanEqual(ssC, params.screen_size))) { //too large, do nothing return; } vec2 uv = vec2(gl_GlobalInvocationID) + vec2(0.5); #ifdef SSAO_BASE generate_SSAO_shadows_internal(out_shadow_term, out_edges, out_weight, uv, params.quality, true); imageStore(dest_image, ivec2(gl_GlobalInvocationID.xy), vec4(out_shadow_term, out_weight / (float(SSAO_ADAPTIVE_TAP_BASE_COUNT) * 4.0), 0.0, 0.0)); #else generate_SSAO_shadows_internal(out_shadow_term, out_edges, out_weight, uv, params.quality, false); // pass in quality levels if (params.quality == 0) { out_edges = vec4(1.0); } imageStore(dest_image, ivec2(gl_GlobalInvocationID.xy), vec4(out_shadow_term, pack_edges(out_edges), 0.0, 0.0)); #endif }