diff options
Diffstat (limited to 'source/blender/draw/engines/eevee_next/shaders/eevee_motion_blur_gather_comp.glsl')
| -rw-r--r-- | source/blender/draw/engines/eevee_next/shaders/eevee_motion_blur_gather_comp.glsl | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/source/blender/draw/engines/eevee_next/shaders/eevee_motion_blur_gather_comp.glsl b/source/blender/draw/engines/eevee_next/shaders/eevee_motion_blur_gather_comp.glsl new file mode 100644 index 00000000000..a7329f77181 --- /dev/null +++ b/source/blender/draw/engines/eevee_next/shaders/eevee_motion_blur_gather_comp.glsl @@ -0,0 +1,221 @@ + +/** + * Perform two gather blur in the 2 motion blur directions + * Based on: + * A Fast and Stable Feature-Aware Motion Blur Filter + * by Jean-Philippe Guertin, Morgan McGuire, Derek Nowrouzezahrai + * + * With modification from the presentation: + * Next Generation Post Processing in Call of Duty Advanced Warfare + * by Jorge Jimenez + */ + +#pragma BLENDER_REQUIRE(common_view_lib.glsl) +#pragma BLENDER_REQUIRE(common_math_lib.glsl) +#pragma BLENDER_REQUIRE(eevee_sampling_lib.glsl) +#pragma BLENDER_REQUIRE(eevee_velocity_lib.glsl) +#pragma BLENDER_REQUIRE(eevee_motion_blur_lib.glsl) + +const int gather_sample_count = 8; + +/* Converts uv velocity into pixel space. Assumes velocity_tx is the same resolution as the + * target post-fx framebuffer. */ +vec4 motion_blur_sample_velocity(sampler2D velocity_tx, vec2 uv) +{ + /* We can load velocity without velocity_resolve() since we resovled during the flatten pass. */ + vec4 velocity = velocity_unpack(texture(velocity_tx, uv)); + return velocity * vec2(textureSize(velocity_tx, 0)).xyxy * motion_blur_buf.motion_scale.xxyy; +} + +vec2 spread_compare(float center_motion_length, float sample_motion_length, float offset_length) +{ + return saturate(vec2(center_motion_length, sample_motion_length) - offset_length + 1.0); +} + +vec2 depth_compare(float center_depth, float sample_depth) +{ + vec2 depth_scale = vec2(-motion_blur_buf.depth_scale, motion_blur_buf.depth_scale); + return saturate(0.5 + depth_scale * (sample_depth - center_depth)); +} + +/* Kill contribution if not going the same direction. */ +float dir_compare(vec2 offset, vec2 sample_motion, float sample_motion_length) +{ + if (sample_motion_length < 0.5) { + return 1.0; + } + return (dot(offset, sample_motion) > 0.0) ? 1.0 : 0.0; +} + +/* Return background (x) and foreground (y) weights. */ +vec2 sample_weights(float center_depth, + float sample_depth, + float center_motion_length, + float sample_motion_length, + float offset_length) +{ + /* Classify foreground/background. */ + vec2 depth_weight = depth_compare(center_depth, sample_depth); + /* Weight if sample is overlapping or under the center pixel. */ + vec2 spread_weight = spread_compare(center_motion_length, sample_motion_length, offset_length); + return depth_weight * spread_weight; +} + +struct Accumulator { + vec4 fg; + vec4 bg; + /** x: Background, y: Foreground, z: dir. */ + vec3 weight; +}; + +void gather_sample(vec2 screen_uv, + float center_depth, + float center_motion_len, + vec2 offset, + float offset_len, + const bool next, + inout Accumulator accum) +{ + vec2 sample_uv = screen_uv - offset * motion_blur_buf.target_size_inv; + vec4 sample_vectors = motion_blur_sample_velocity(velocity_tx, sample_uv); + vec2 sample_motion = (next) ? sample_vectors.zw : sample_vectors.xy; + float sample_motion_len = length(sample_motion); + float sample_depth = texture(depth_tx, sample_uv).r; + vec4 sample_color = textureLod(in_color_tx, sample_uv, 0.0); + + sample_depth = get_view_z_from_depth(sample_depth); + + vec3 weights; + weights.xy = sample_weights( + center_depth, sample_depth, center_motion_len, sample_motion_len, offset_len); + weights.z = dir_compare(offset, sample_motion, sample_motion_len); + weights.xy *= weights.z; + + accum.fg += sample_color * weights.y; + accum.bg += sample_color * weights.x; + accum.weight += weights; +} + +void gather_blur(vec2 screen_uv, + vec2 center_motion, + float center_depth, + vec2 max_motion, + float ofs, + const bool next, + inout Accumulator accum) +{ + float center_motion_len = length(center_motion); + float max_motion_len = length(max_motion); + + /* Tile boundaries randomization can fetch a tile where there is less motion than this pixel. + * Fix this by overriding the max_motion. */ + if (max_motion_len < center_motion_len) { + max_motion_len = center_motion_len; + max_motion = center_motion; + } + + if (max_motion_len < 0.5) { + return; + } + + int i; + float t, inc = 1.0 / float(gather_sample_count); + for (i = 0, t = ofs * inc; i < gather_sample_count; i++, t += inc) { + gather_sample(screen_uv, + center_depth, + center_motion_len, + max_motion * t, + max_motion_len * t, + next, + accum); + } + + if (center_motion_len < 0.5) { + return; + } + + for (i = 0, t = ofs * inc; i < gather_sample_count; i++, t += inc) { + /* Also sample in center motion direction. + * Allow recovering motion where there is conflicting + * motion between foreground and background. */ + gather_sample(screen_uv, + center_depth, + center_motion_len, + center_motion * t, + center_motion_len * t, + next, + accum); + } +} + +void main() +{ + ivec2 texel = ivec2(gl_GlobalInvocationID.xy); + vec2 uv = (vec2(texel) + 0.5) / vec2(textureSize(depth_tx, 0).xy); + + if (!in_texture_range(texel, depth_tx)) { + return; + } + + /* Data of the center pixel of the gather (target). */ + float center_depth = get_view_z_from_depth(texelFetch(depth_tx, texel, 0).r); + vec4 center_motion = motion_blur_sample_velocity(velocity_tx, uv); + + vec4 center_color = textureLod(in_color_tx, uv, 0.0); + + float noise_offset = sampling_rng_1D_get(SAMPLING_TIME); + /** TODO(fclem) Blue noise. */ + vec2 rand = vec2(interlieved_gradient_noise(vec2(gl_GlobalInvocationID.xy), 0, noise_offset), + interlieved_gradient_noise(vec2(gl_GlobalInvocationID.xy), 1, noise_offset)); + + /* Randomize tile boundary to avoid ugly discontinuities. Randomize 1/4th of the tile. + * Note this randomize only in one direction but in practice it's enough. */ + rand.x = rand.x * 2.0 - 1.0; + ivec2 tile = (texel + ivec2(rand.x * float(MOTION_BLUR_TILE_SIZE) * 0.25)) / + MOTION_BLUR_TILE_SIZE; + tile = clamp(tile, ivec2(0), imageSize(in_tiles_img) - 1); + /* NOTE: Tile velocity is already in pixel space and with correct zw sign. */ + vec4 max_motion; + /* Load dilation result from the indirection table. */ + ivec2 tile_prev; + motion_blur_tile_indirection_load(tile_indirection_buf, MOTION_PREV, tile, tile_prev); + max_motion.xy = imageLoad(in_tiles_img, tile_prev).xy; + ivec2 tile_next; + motion_blur_tile_indirection_load(tile_indirection_buf, MOTION_NEXT, tile, tile_next); + max_motion.zw = imageLoad(in_tiles_img, tile_next).zw; + + Accumulator accum; + accum.weight = vec3(0.0, 0.0, 1.0); + accum.bg = vec4(0.0); + accum.fg = vec4(0.0); + /* First linear gather. time = [T - delta, T] */ + gather_blur(uv, center_motion.xy, center_depth, max_motion.xy, rand.y, false, accum); + /* Second linear gather. time = [T, T + delta] */ + gather_blur(uv, center_motion.zw, center_depth, max_motion.zw, rand.y, true, accum); + +#if 1 /* Own addition. Not present in reference implementation. */ + /* Avoid division by 0.0. */ + float w = 1.0 / (50.0 * float(gather_sample_count) * 4.0); + accum.bg += center_color * w; + accum.weight.x += w; + /* NOTE: In Jimenez's presentation, they used center sample. + * We use background color as it contains more information for foreground + * elements that have not enough weights. + * Yield better blur in complex motion. */ + center_color = accum.bg / accum.weight.x; +#endif + /* Merge background. */ + accum.fg += accum.bg; + accum.weight.y += accum.weight.x; + /* Balance accumulation for failed samples. + * We replace the missing foreground by the background. */ + float blend_fac = saturate(1.0 - accum.weight.y / accum.weight.z); + vec4 out_color = (accum.fg / accum.weight.z) + center_color * blend_fac; + +#if 0 /* For debugging. */ + out_color.rgb = out_color.ggg; + out_color.rg += max_motion.xy; +#endif + + imageStore(out_color_img, texel, out_color); +} |