source/blender/draw/engines/eevee_next/eevee_ao.cc

@@ -61,6 +61,10 @@ void AmbientOcclusion::init()
 
   eGPUTextureUsage usage = GPU_TEXTURE_USAGE_ATTACHMENT | GPU_TEXTURE_USAGE_SHADER_READ;
   horizons_tx_.ensure_2d(GPU_RGBA8, inst_.film.render_extent_get(), usage);
+
+  /* Compute pixel size. Size is multiplied by 2 because it is applied in NDC [-1..1] range. */
+  rt_data_.pixel_size = float2(2.0f) / float2(inst_.film.render_extent_get());
+  rt_data_.push_update();
 }
 
 void AmbientOcclusion::sync()

source/blender/draw/engines/eevee_next/eevee_ao.hh

@@ -47,6 +47,14 @@ class AmbientOcclusion {
   void sync();
 
   void render(View &view);
+
+  template<typename T> void bind_resources(draw::detail::PassBase<T> *pass)
+  {
+    inst_.hiz_buffer.bind_resources(pass);
+    pass->bind_ubo(AO_BUF_SLOT, &data_);
+    pass->bind_ubo(RAYTRACE_BUF_SLOT, &rt_data_);
+    pass->bind_texture(AO_HORIZONS_TEX_SLOT, data_.enabled ? &horizons_tx_ : &dummy_horizons_tx_);
+  }
 };
 
 /** \} */

source/blender/draw/engines/eevee_next/eevee_pipeline.cc

@@ -150,6 +150,7 @@ void ForwardPipeline::sync()
       inst_.shadows.bind_resources(&opaque_ps_);
       inst_.sampling.bind_resources(&opaque_ps_);
       inst_.cryptomatte.bind_resources(&opaque_ps_);
+      inst_.ao.bind_resources(&opaque_ps_);
     }
 
     opaque_single_sided_ps_ = &opaque_ps_.sub("SingleSided");
@@ -175,6 +176,7 @@ void ForwardPipeline::sync()
     inst_.lights.bind_resources(&sub);
     inst_.shadows.bind_resources(&sub);
     inst_.sampling.bind_resources(&sub);
+    inst_.ao.bind_resources(&sub);
   }
 }
 
@@ -328,6 +330,7 @@ void DeferredLayer::begin_sync()
 
       inst_.sampling.bind_resources(&gbuffer_ps_);
       inst_.cryptomatte.bind_resources(&gbuffer_ps_);
+      inst_.ao.bind_resources(&gbuffer_ps_);
     }
 
     DRWState state = DRW_STATE_WRITE_COLOR | DRW_STATE_BLEND_CUSTOM | DRW_STATE_DEPTH_EQUAL |
@@ -370,6 +373,7 @@ void DeferredLayer::end_sync()
     inst_.shadows.bind_resources(&eval_light_ps_);
     inst_.sampling.bind_resources(&eval_light_ps_);
     inst_.hiz_buffer.bind_resources(&eval_light_ps_);
+    inst_.ao.bind_resources(&eval_light_ps_);
 
     eval_light_ps_.barrier(GPU_BARRIER_TEXTURE_FETCH | GPU_BARRIER_SHADER_IMAGE_ACCESS);
     eval_light_ps_.draw_procedural(GPU_PRIM_TRIS, 1, 3);

source/blender/draw/engines/eevee_next/eevee_shader.cc

@@ -254,6 +254,13 @@ void ShaderModule::material_create_info_ammend(GPUMaterial *gpumat, GPUCodegenOu
     info.define("MAT_RENDER_PASS_SUPPORT");
   }
 
+  if (GPU_material_flag_get(gpumat, GPU_MATFLAG_AO) &&
+      ELEM(pipeline_type, MAT_PIPE_FORWARD, MAT_PIPE_DEFERRED) &&
+      ELEM(geometry_type, MAT_GEOM_MESH, MAT_GEOM_CURVES))
+  {
+    info.define("MAT_AO");
+  }
+
   if (GPU_material_flag_get(gpumat, GPU_MATFLAG_TRANSPARENT)) {
     info.define("MAT_TRANSPARENT");
     /* Transparent material do not have any velocity specific pipeline. */

source/blender/draw/engines/eevee_next/shaders/eevee_ao_lib.glsl

@@ -24,21 +24,23 @@ float cone_cosine(float r)
  * http://blog.selfshadow.com/publications/s2016-shading-course/activision/s2016_pbs_activision_occlusion.pptx
  */
 
-#if defined(MESH_SHADER)
+/* TODO(Miguel Pozo) */
+
+#if defined(MAT_GEOM_MESH)
 #  if !defined(USE_ALPHA_HASH)
 #    if !defined(DEPTH_SHADER)
-#      if !defined(USE_ALPHA_BLEND)
+#      if !defined(MAT_TRANSPARENT)
 #        if !defined(USE_REFRACTION)
-#          define ENABLE_DEFERED_AO
+#          define ENABLE_DEFERRED_AO
 #        endif
 #      endif
 #    endif
 #  endif
 #endif
 
-#ifndef ENABLE_DEFERED_AO
+#ifndef ENABLE_DEFERRED_AO
 #  if defined(STEP_RESOLVE)
-#    define ENABLE_DEFERED_AO
+#    define ENABLE_DEFERRED_AO
 #  endif
 #endif
 
@@ -440,9 +442,9 @@ OcclusionData occlusion_load(vec3 vP, float custom_occlusion)
   /* Default to fully opened cone. */
   OcclusionData data = NO_OCCLUSION_DATA;
 
-#ifdef ENABLE_DEFERED_AO
-  if ((ao_buf.settings & AO_ENABLED) != 0) {
-    data = unpack_occlusion_data(texelFetch(horizonBuffer, ivec2(gl_FragCoord.xy), 0));
+#ifdef ENABLE_DEFERRED_AO
+  if (ao_buf.enabled) {
+    data = unpack_occlusion_data(texelFetch(horizons_tx, ivec2(gl_FragCoord.xy), 0));
   }
 #else
   /* For blended surfaces. */
@@ -457,30 +459,3 @@ OcclusionData occlusion_load(vec3 vP, float custom_occlusion)
 #ifndef GPU_FRAGMENT_SHADER
 #  undef gl_FragCoord
 #endif
-
-float ambient_occlusion_eval(vec3 normal,
-                             float max_distance,
-                             const float inverted,
-                             const float sample_count)
-{
-  /* Avoid multiline define causing compiler issues. */
-  /* clang-format off */
-#if defined(GPU_FRAGMENT_SHADER) && (defined(MESH_SHADER) || defined(HAIR_SHADER)) && !defined(DEPTH_SHADER) && !defined(VOLUMETRICS)
-  /* clang-format on */
-  vec3 bent_normal;
-  vec4 rand = texelfetch_noise_tex(gl_FragCoord.xy);
-  OcclusionData data = occlusion_search(
-      viewPosition, hiz_tx, max_distance, inverted, sample_count);
-
-  vec3 V = cameraVec(worldPosition);
-  vec3 N = normalize(normal);
-  vec3 Ng = safe_normalize(cross(dFdx(worldPosition), dFdy(worldPosition)));
-
-  float unused_error, visibility;
-  vec3 unused;
-  occlusion_eval(data, V, N, Ng, inverted, visibility, unused_error, unused);
-  return visibility;
-#else
-  return 1.0;
-#endif
-}

source/blender/draw/engines/eevee_next/shaders/eevee_deferred_light_frag.glsl

@@ -9,6 +9,7 @@
 #pragma BLENDER_REQUIRE(eevee_gbuffer_lib.glsl)
 #pragma BLENDER_REQUIRE(common_view_lib.glsl)
 #pragma BLENDER_REQUIRE(eevee_light_eval_lib.glsl)
+#pragma BLENDER_REQUIRE(eevee_ao_lib.glsl)
 
 void main()
 {

source/blender/draw/engines/eevee_next/shaders/eevee_nodetree_lib.glsl

@@ -199,12 +199,25 @@ Closure closure_mix(Closure cl1, Closure cl2, float fac)
 }
 
 float ambient_occlusion_eval(vec3 normal,
-                             float distance,
+                             float max_distance,
                              const float inverted,
                              const float sample_count)
 {
-  /* TODO */
+#if defined(GPU_FRAGMENT_SHADER) && defined(MAT_AO) && !defined(MAT_DEPTH) && !defined(MAT_SHADOW)
+  vec3 vP = transform_point(ViewMatrix, g_data.P);
+  OcclusionData data = occlusion_search(vP, hiz_tx, max_distance, inverted, sample_count);
+
+  vec3 V = cameraVec(g_data.P);
+  vec3 N = g_data.N;
+  vec3 Ng = g_data.Ng;
+
+  float unused_error, visibility;
+  vec3 unused;
+  occlusion_eval(data, V, N, Ng, inverted, visibility, unused_error, unused);
+  return visibility;
+#else
   return 1.0;
+#endif
 }
 
 #ifndef GPU_METAL

source/blender/draw/engines/eevee_next/shaders/eevee_surf_deferred_frag.glsl

@@ -10,6 +10,7 @@
 #pragma BLENDER_REQUIRE(common_view_lib.glsl)
 #pragma BLENDER_REQUIRE(common_math_lib.glsl)
 #pragma BLENDER_REQUIRE(common_hair_lib.glsl)
+#pragma BLENDER_REQUIRE(eevee_ao_lib.glsl)
 #pragma BLENDER_REQUIRE(eevee_surf_lib.glsl)
 #pragma BLENDER_REQUIRE(eevee_nodetree_lib.glsl)
 #pragma BLENDER_REQUIRE(eevee_sampling_lib.glsl)

source/blender/draw/engines/eevee_next/shaders/eevee_surf_forward_frag.glsl

@@ -8,6 +8,7 @@
 #pragma BLENDER_REQUIRE(common_hair_lib.glsl)
 #pragma BLENDER_REQUIRE(common_math_lib.glsl)
 #pragma BLENDER_REQUIRE(common_view_lib.glsl)
+#pragma BLENDER_REQUIRE(eevee_ao_lib.glsl)
 #pragma BLENDER_REQUIRE(eevee_light_eval_lib.glsl)
 #pragma BLENDER_REQUIRE(eevee_nodetree_lib.glsl)
 #pragma BLENDER_REQUIRE(eevee_sampling_lib.glsl)

source/blender/draw/engines/eevee_next/shaders/infos/eevee_ao_info.hh

@@ -9,7 +9,7 @@ GPU_SHADER_CREATE_INFO(eevee_raytrace_lib)
 
 GPU_SHADER_CREATE_INFO(eevee_ao_lib)
     .additional_info("eevee_raytrace_lib", "eevee_utility_texture")
-    .sampler(AO_HORIZONS_TEX_SLOT, ImageType::FLOAT_2D, "horizons_buffer_tx")
+    .sampler(AO_HORIZONS_TEX_SLOT, ImageType::FLOAT_2D, "horizons_tx")
     .uniform_buf(AO_BUF_SLOT, "AOData", "ao_buf");
 
 GPU_SHADER_CREATE_INFO(eevee_ao)

source/blender/draw/engines/eevee_next/shaders/infos/eevee_deferred_info.hh

@@ -41,6 +41,7 @@ GPU_SHADER_CREATE_INFO(eevee_deferred_light)
                      "eevee_deferred_base",
                      "eevee_hiz_data",
                      "eevee_render_pass_out",
+                     "eevee_ao_lib",
                      "draw_view",
                      "draw_fullscreen")
     .do_static_compilation(true);

source/blender/draw/engines/eevee_next/shaders/infos/eevee_material_info.hh

@@ -108,7 +108,8 @@ GPU_SHADER_CREATE_INFO(eevee_surf_deferred)
                      "eevee_utility_texture",
                      "eevee_sampling_data",
                      "eevee_render_pass_out",
-                     "eevee_cryptomatte_out");
+                     "eevee_cryptomatte_out",
+                     "eevee_ao_lib");
 
 GPU_SHADER_CREATE_INFO(eevee_surf_forward)
     .vertex_out(eevee_surf_iface)
@@ -122,7 +123,8 @@ GPU_SHADER_CREATE_INFO(eevee_surf_forward)
                      "eevee_camera",
                      "eevee_utility_texture",
                      "eevee_sampling_data",
-                     "eevee_shadow_data"
+                     "eevee_shadow_data",
+                     "eevee_ao_lib"
                      /* Optionally added depending on the material. */
                      // "eevee_render_pass_out",
                      // "eevee_cryptomatte_out",
@@ -131,6 +133,7 @@ GPU_SHADER_CREATE_INFO(eevee_surf_forward)
     );
 
 GPU_SHADER_CREATE_INFO(eevee_surf_depth)
+    .define("MAT_DEPTH")
     .vertex_out(eevee_surf_iface)
     .fragment_source("eevee_surf_depth_frag.glsl")
     .additional_info("eevee_sampling_data", "eevee_camera", "eevee_utility_texture");