source/blender/draw/CMakeLists.txt

@@ -154,6 +154,7 @@ set(SRC
   engines/eevee_next/eevee_material.cc
   engines/eevee_next/eevee_motion_blur.cc
   engines/eevee_next/eevee_pipeline.cc
+  engines/eevee_next/eevee_reflection_probes.cc
   engines/eevee_next/eevee_renderbuffers.cc
   engines/eevee_next/eevee_sampling.cc
   engines/eevee_next/eevee_shader.cc
@@ -294,6 +295,7 @@ set(SRC
   engines/eevee_next/eevee_material.hh
   engines/eevee_next/eevee_motion_blur.hh
   engines/eevee_next/eevee_pipeline.hh
+  engines/eevee_next/eevee_reflection_probes.hh
   engines/eevee_next/eevee_renderbuffers.hh
   engines/eevee_next/eevee_sampling.hh
   engines/eevee_next/eevee_shader.hh
@@ -508,6 +510,7 @@ set(GLSL_SRC
   engines/eevee_next/shaders/eevee_motion_blur_gather_comp.glsl
   engines/eevee_next/shaders/eevee_motion_blur_lib.glsl
   engines/eevee_next/shaders/eevee_nodetree_lib.glsl
+  engines/eevee_next/shaders/eevee_reflection_probe_lib.glsl
   engines/eevee_next/shaders/eevee_sampling_lib.glsl
   engines/eevee_next/shaders/eevee_shadow_debug_frag.glsl
   engines/eevee_next/shaders/eevee_shadow_lib.glsl

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

@@ -26,6 +26,9 @@
 #define CULLING_ZBIN_GROUP_SIZE 1024
 #define CULLING_TILE_GROUP_SIZE 256
 
+/* Reflection probes */
+#define REFLECTION_PROBES_MAX 256
+
 /**
  * IMPORTANT: Some data packing are tweaked for these values.
  * Be sure to update them accordingly.
@@ -108,6 +111,7 @@
 #define SHADOW_ATLAS_TEX_SLOT 5
 #define SSS_TRANSMITTANCE_TEX_SLOT 6
 #define IRRADIANCE_ATLAS_TEX_SLOT 7
+#define REFLECTION_PROBE_TEX_SLOT 8
 /* Only during shadow rendering. */
 #define SHADOW_RENDER_MAP_SLOT 4
 
@@ -143,6 +147,8 @@
 #define SHADOW_PAGE_INFO_SLOT 4
 #define SAMPLING_BUF_SLOT 6
 #define CRYPTOMATTE_BUF_SLOT 7
+/* Only during reflection probe evaluation. */
+#define REFLECTION_PROBE_BUF_SLOT 4
 
 /* Only during pre-pass. */
 #define VELOCITY_OBJ_PREV_BUF_SLOT 0

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

@@ -70,6 +70,7 @@ void Instance::init(const int2 &output_res,
   motion_blur.init();
   main_view.init();
   irradiance_cache.init();
+  reflection_probes.init();
 }
 
 void Instance::init_light_bake(Depsgraph *depsgraph, draw::Manager *manager)
@@ -211,6 +212,8 @@ void Instance::object_sync(Object *ob)
         sync.sync_gpencil(ob, ob_handle, res_handle);
         break;
       case OB_LIGHTPROBE:
+        sync.sync_light_probe(ob, ob_handle, res_handle);
+        /* TODO: should be moved into sync module? */
         light_probes.sync_probe(ob, ob_handle);
         break;
       default:
@@ -239,6 +242,7 @@ void Instance::end_sync()
   lights.end_sync();
   sampling.end_sync();
   subsurface.end_sync();
+  reflection_probes.end_sync();
   film.end_sync();
   cryptomatte.end_sync();
   pipelines.end_sync();

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

@@ -27,6 +27,7 @@
 #include "eevee_material.hh"
 #include "eevee_motion_blur.hh"
 #include "eevee_pipeline.hh"
+#include "eevee_reflection_probes.hh"
 #include "eevee_renderbuffers.hh"
 #include "eevee_sampling.hh"
 #include "eevee_shader.hh"
@@ -54,6 +55,7 @@ class Instance {
   PipelineModule pipelines;
   ShadowModule shadows;
   LightModule lights;
+  ReflectionProbeModule reflection_probes;
   VelocityModule velocity;
   MotionBlurModule motion_blur;
   DepthOfField depth_of_field;
@@ -105,6 +107,7 @@ class Instance {
         pipelines(*this),
         shadows(*this),
         lights(*this),
+        reflection_probes(*this),
         velocity(*this),
         motion_blur(*this),
         depth_of_field(*this),

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

@@ -56,6 +56,107 @@ void WorldPipeline::render(View &view)
 
 /** \} */
 
+/* -------------------------------------------------------------------- */
+/** \name World Probe Pipeline
+ * \{ */
+
+void WorldProbePipeline::sync()
+{
+  for (int face : IndexRange(6)) {
+    CubemapSide &side = sides_[face];
+    /* View */
+    float4x4 view_m4 = cubeface_mat(face);
+    float4x4 win_m4;
+    cubeface_winmat_get(win_m4, 1.0f, 10.0f);
+    side.view.sync(view_m4, win_m4);
+
+    side.cubemap_face_ps.init();
+    side.cubemap_face_ps.state_set(DRW_STATE_WRITE_COLOR | DRW_STATE_DEPTH_ALWAYS);
+  }
+  const int2 extent(1);
+  constexpr eGPUTextureUsage usage = GPU_TEXTURE_USAGE_MEMORYLESS | GPU_TEXTURE_USAGE_SHADER_WRITE;
+  dummy_cryptomatte_tx_.ensure_2d(GPU_RGBA32F, extent, usage);
+  dummy_renderpass_tx_.ensure_2d(GPU_RGBA16F, extent, usage);
+  dummy_aov_color_tx_.ensure_2d_array(GPU_RGBA16F, extent, 1, usage);
+  dummy_aov_value_tx_.ensure_2d_array(GPU_R16F, extent, 1, usage);
+
+  has_draw_commands_ = false;
+}
+
+void WorldProbePipeline::sync(GPUMaterial *gpumat)
+{
+  for (int face : IndexRange(6)) {
+    sync(gpumat, face);
+  }
+  has_draw_commands_ = true;
+}
+
+void WorldProbePipeline::sync(GPUMaterial *gpumat, int face)
+{
+  Manager &manager = *inst_.manager;
+
+  CubemapSide &side = sides_[face];
+
+  /* Framebuffer. */
+  Texture &cubemap = inst_.reflection_probes.cubemaps_tx_;
+  side.cubemap_face_fb.ensure(GPU_ATTACHMENT_NONE, GPU_ATTACHMENT_TEXTURE_CUBEFACE(cubemap, face));
+
+  ResourceHandle handle = manager.resource_handle(float4x4::identity());
+  PassSimple &pass = side.cubemap_face_ps;
+
+  pass.framebuffer_set(&side.cubemap_face_fb);
+  pass.material_set(manager, gpumat);
+  pass.push_constant("world_opacity_fade", 1.0f);
+
+  pass.bind_texture(RBUFS_UTILITY_TEX_SLOT, inst_.pipelines.utility_tx);
+  pass.bind_ubo(CAMERA_BUF_SLOT, inst_.camera.ubo_get());
+  pass.bind_ubo(RBUFS_BUF_SLOT, &inst_.render_buffers.data);
+  pass.bind_image("rp_normal_img", dummy_renderpass_tx_);
+  pass.bind_image("rp_light_img", dummy_renderpass_tx_);
+  pass.bind_image("rp_diffuse_color_img", dummy_renderpass_tx_);
+  pass.bind_image("rp_specular_color_img", dummy_renderpass_tx_);
+  pass.bind_image("rp_emission_img", dummy_renderpass_tx_);
+  pass.bind_image("rp_cryptomatte_img", dummy_cryptomatte_tx_);
+  pass.bind_image("rp_color_img", dummy_aov_color_tx_);
+  pass.bind_image("rp_value_img", dummy_aov_value_tx_);
+  /* Required by validation layers. */
+  inst_.cryptomatte.bind_resources(&pass);
+
+  pass.bind_image("aov_color_img", dummy_aov_color_tx_);
+  pass.bind_image("aov_value_img", dummy_aov_value_tx_);
+  pass.bind_ssbo("aov_buf", &inst_.film.aovs_info);
+
+  pass.draw(DRW_cache_fullscreen_quad_get(), handle);
+
+  pass.barrier(GPU_BARRIER_SHADER_IMAGE_ACCESS);
+}
+
+void WorldProbePipeline::render()
+{
+  if (!has_draw_commands_) {
+    return;
+  }
+  GPUFrameBuffer *previous_framebuffer = GPU_framebuffer_active_get();
+
+  GPU_debug_group_begin("World.Probe");
+  for (int face : IndexRange(6)) {
+    sides_[face].render(inst_);
+  }
+  GPU_debug_group_end();
+
+  GPU_texture_update_mipmap_chain(inst_.reflection_probes.cubemaps_tx_);
+  if (previous_framebuffer) {
+    GPU_framebuffer_bind(previous_framebuffer);
+  }
+}
+
+void WorldProbePipeline::CubemapSide::render(Instance &instance)
+{
+  instance.manager->submit(cubemap_face_ps, view);
+}
+
+/** \} */
+
 /* -------------------------------------------------------------------- */
 /** \name Shadow Pipeline
  *
@@ -371,6 +472,7 @@ 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_.reflection_probes.bind_resources(&eval_light_ps_);
     inst_.irradiance_cache.bind_resources(&eval_light_ps_);
 
     eval_light_ps_.barrier(GPU_BARRIER_TEXTURE_FETCH | GPU_BARRIER_SHADER_IMAGE_ACCESS);

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

@@ -43,6 +43,56 @@ class WorldPipeline {
 
 /** \} */
 
+/* -------------------------------------------------------------------- */
+/** \name World Probe Pipeline
+ *
+ * Render reflection probe of the world background.
+ * \{ */
+
+class WorldProbePipeline {
+ private:
+  Instance &inst_;
+
+  Texture dummy_renderpass_tx_;
+  Texture dummy_cryptomatte_tx_;
+  Texture dummy_aov_color_tx_;
+  Texture dummy_aov_value_tx_;
+
+  struct CubemapSide {
+    PassSimple cubemap_face_ps;
+    View view;
+    Framebuffer cubemap_face_fb;
+    void render(Instance &instance);
+  };
+
+  /**
+   * Keep track if the world probe needs to be updated. This should only be the case when the
+   * world is updated. This flag is used to skip updating mipmaps when the world isn't changed.
+   */
+  bool has_draw_commands_ = false;
+
+  CubemapSide sides_[6] = {
+      {{"PosX"}, {"PosX"}},
+      {{"NegX"}, {"NegX"}},
+      {{"PosY"}, {"PosY"}},
+      {{"NegY"}, {"NegY"}},
+      {{"PosZ"}, {"PosZ"}},
+      {{"NegZ"}, {"NegZ"}},
+  };
+
+ public:
+  WorldProbePipeline(Instance &inst) : inst_(inst){};
+
+  void sync();
+  void sync(GPUMaterial *gpumat);
+  void render();
+
+ private:
+  void sync(GPUMaterial *gpumat, int face);
+};  // namespace blender::eevee
+
+/** \} */
+
 /* -------------------------------------------------------------------- */
 /** \name Shadow Pass
  *
@@ -288,6 +338,7 @@ class UtilityTexture : public Texture {
 class PipelineModule {
  public:
   WorldPipeline world;
+  WorldProbePipeline world_probe;
   DeferredPipeline deferred;
   ForwardPipeline forward;
   ShadowPipeline shadow;
@@ -297,13 +348,19 @@ class PipelineModule {
 
  public:
   PipelineModule(Instance &inst)
-      : world(inst), deferred(inst), forward(inst), shadow(inst), capture(inst){};
+      : world(inst),
+        world_probe(inst),
+        deferred(inst),
+        forward(inst),
+        shadow(inst),
+        capture(inst){};
 
   void begin_sync()
   {
     deferred.begin_sync();
     forward.sync();
     shadow.sync();
+    world_probe.sync();
     capture.sync();
   }
 

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

@@ -0,0 +1,445 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later
+ * Copyright 2023 Blender Foundation. */
+
+#include <sstream>
+
+#include "BLI_bit_vector.hh"
+#include "BLI_span.hh"
+
+#include "eevee_instance.hh"
+#include "eevee_reflection_probes.hh"
+
+namespace blender::eevee {
+
+void ReflectionProbeModule::init()
+{
+  if (cubemaps_.is_empty()) {
+    cubemaps_.reserve(INITIAL_PROBES);
+
+    ReflectionProbeData init_probe_data = {};
+    init_probe_data.layer = -1;
+    for (int i : IndexRange(REFLECTION_PROBES_MAX)) {
+      data_buf_[i] = init_probe_data;
+    }
+
+    /* Initialize the world cubemap. */
+    ReflectionProbeData world_probe_data{};
+    world_probe_data.layer = 0;
+    world_probe_data.layer_subdivision = WORLD_SUBDIVISION_LEVEL;
+    world_probe_data.area_index = 0;
+    world_probe_data.color = float4(0.0f);
+    world_probe_data.pos = float3(0.0f);
+    world_probe_data.influence_distance = 999999.0f;
+    world_probe_data.falloff = 0.0f;
+    data_buf_[0] = world_probe_data;
+
+    ReflectionProbe world_cubemap;
+    world_cubemap.type = ReflectionProbe::Type::WORLD;
+    world_cubemap.is_dirty = true;
+    world_cubemap.index = 0;
+    cubemaps_.append(world_cubemap);
+
+    cubemaps_tx_.ensure_cube_array(GPU_RGBA16F,
+                                   MAX_RESOLUTION,
+                                   INITIAL_PROBES,
+                                   GPU_TEXTURE_USAGE_SHADER_READ | GPU_TEXTURE_USAGE_ATTACHMENT,
+                                   NULL,
+                                   MIPMAP_LEVELS);
+    GPU_texture_mipmap_mode(cubemaps_tx_, true, true);
+  }
+
+  for (ReflectionProbe &reflection_probe : cubemaps_) {
+    if (reflection_probe.type == ReflectionProbe::Type::PROBE) {
+      reflection_probe.is_used = false;
+    }
+  }
+}
+
+int ReflectionProbeModule::needed_layers_get() const
+{
+  const int max_probe_data_index = reflection_probe_data_index_max();
+  int max_layer = 0;
+  for (const ReflectionProbeData &data :
+       Span<ReflectionProbeData>(data_buf_.data(), max_probe_data_index + 1))
+  {
+    max_layer = max_ii(max_layer, data.layer);
+  }
+  return max_layer + 1;
+}
+
+void ReflectionProbeModule::sync(const ReflectionProbe &cubemap)
+{
+  switch (cubemap.type) {
+    case ReflectionProbe::Type::WORLD: {
+      GPUMaterial *world_material = instance_.world.get_world_material();
+      instance_.pipelines.world_probe.sync(world_material);
+      break;
+    }
+    case ReflectionProbe::Type::PROBE: {
+      // upload the baked probe to the cubemaps.
+      upload_dummy_cubemap(cubemap);
+      break;
+    }
+    case ReflectionProbe::Type::UNUSED: {
+      break;
+    }
+  }
+}
+
+void ReflectionProbeModule::set_world_dirty()
+{
+  cubemaps_[WORLD_SLOT].is_dirty = true;
+}
+
+void ReflectionProbeModule::sync_object(Object *ob,
+                                        ObjectHandle &ob_handle,
+                                        ResourceHandle res_handle,
+                                        bool is_dirty)
+{
+  const ::LightProbe *light_probe = (::LightProbe *)ob->data;
+  ReflectionProbe &probe = find_or_insert(ob_handle, REFLECTION_PROBE_SUBDIVISION_LEVEL);
+  probe.is_dirty |= is_dirty;
+  probe.is_used = true;
+
+  /* TODO: remove debug color.*/
+  ReflectionProbeData &probe_data = data_buf_[probe.index];
+  probe_data.color = ob->color;
+  probe_data.influence_distance = light_probe->distinf;
+  probe_data.falloff = light_probe->falloff;
+  probe_data.pos = float3(float4x4(ob->object_to_world) * float4(0.0, 0.0, 0.0, 1.0));
+}
+
+ReflectionProbe &ReflectionProbeModule::find_or_insert(ObjectHandle &ob_handle,
+                                                       int subdivision_level)
+{
+  ReflectionProbe *first_unused = nullptr;
+  for (ReflectionProbe &reflection_probe : cubemaps_) {
+    if (reflection_probe.type == ReflectionProbe::Type::PROBE &&
+        reflection_probe.object_hash_value == ob_handle.object_key.hash_value)
+    {
+      return reflection_probe;
+    }
+    if (first_unused == nullptr && reflection_probe.type == ReflectionProbe::Type::UNUSED) {
+      first_unused = &reflection_probe;
+    }
+  }
+
+  if (first_unused == nullptr) {
+    ReflectionProbe new_slot{};
+    cubemaps_.append_as(new_slot);
+    first_unused = &cubemaps_.last();
+  }
+  BLI_assert(first_unused != nullptr);
+  first_unused->index = -1;
+  ReflectionProbeData probe_data = find_empty_reflection_probe_data(subdivision_level);
+
+  first_unused->is_dirty = true;
+  first_unused->object_hash_value = ob_handle.object_key.hash_value;
+  first_unused->type = ReflectionProbe::Type::PROBE;
+  first_unused->index = reflection_probe_data_index_max() + 1;
+
+  data_buf_[first_unused->index] = probe_data;
+
+  return *first_unused;
+}
+
+int ReflectionProbeModule::reflection_probe_data_index_max() const
+{
+  int result = -1;
+  for (const ReflectionProbe &probe : cubemaps_) {
+    if (probe.type != ReflectionProbe::Type::UNUSED) {
+      result = max_ii(result, probe.index);
+    }
+  }
+  return result;
+}
+
+/**
+ * Utility class to find a location in the cubemap that can be used to store a new probe cubemap in
+ * a specified subdivision level.
+ */
+class ProbeLocationFinder {
+  BitVector<> taken_spots_;
+  int probes_per_dimension_;
+  int probes_per_layer_;
+  int subdivision_level_;
+
+ public:
+  ProbeLocationFinder(int num_layers, int subdivision_level)
+  {
+    subdivision_level_ = subdivision_level;
+    probes_per_dimension_ = 1 << subdivision_level_;
+    probes_per_layer_ = probes_per_dimension_ * probes_per_dimension_;
+    int num_spots = num_layers * probes_per_layer_;
+    taken_spots_.resize(num_spots, false);
+  }
+
+  /**
+   * Mark space to be occupied by the given probe_data.
+   *
+   * The input probe data can be stored in a different subdivision level and should be converted to
+   * the subdivision level what we are looking for.
+   */
+  void mark_space_used(const ReflectionProbeData &probe_data)
+  {
+    /* Number of spots that the probe data will occupied in a single dimension. */
+    int clamped_subdivision_shift = max_ii(probe_data.layer_subdivision - subdivision_level_, 0);
+    int spots_per_dimension = 1 << max_ii(subdivision_level_ - probe_data.layer_subdivision, 0);
+    int probes_per_dimension_in_probe_data = 1 << probe_data.layer_subdivision;
+    int2 pos_in_probe_data = int2(probe_data.area_index % probes_per_dimension_in_probe_data,
+                                  probe_data.area_index / probes_per_dimension_in_probe_data);
+    int2 pos_in_location_finder = int2(pos_in_probe_data.x >> clamped_subdivision_shift,
+                                       pos_in_probe_data.y >> clamped_subdivision_shift);
+    int layer_offset = probe_data.layer * probes_per_layer_;
+    for (int y : IndexRange(spots_per_dimension)) {
+      for (int x : IndexRange(spots_per_dimension)) {
+        int2 pos = pos_in_location_finder + int2(x, y);
+        int area_index = pos.x + pos.y * probes_per_dimension_;
+        taken_spots_[area_index + layer_offset].set();
+      }
+    }
+  }
+
+  /**
+   * Get the first free spot.
+   *
+   * .x contains the layer the first free spot was detected.
+   * .y contains the area_index to use.
+   *
+   * Asserts when no free spot is found. ProbeLocationFinder should always be initialized with an
+   * additional layer to make sure that there is always a free spot.
+   */
+  ReflectionProbeData first_free_spot() const
+  {
+    ReflectionProbeData result = {};
+    result.layer_subdivision = subdivision_level_;
+    for (int index : taken_spots_.index_range()) {
+      if (!taken_spots_[index]) {
+        int layer = index / probes_per_layer_;
+        int area_index = index % probes_per_layer_;
+        result.layer = layer;
+        result.area_index = area_index;
+        return result;
+      }
+    }
+
+    BLI_assert_unreachable();
+    return result;
+  }
+};
+
+ReflectionProbeData ReflectionProbeModule::find_empty_reflection_probe_data(
+    int subdivision_level) const
+{
+  ProbeLocationFinder location_finder(needed_layers_get() + 1, subdivision_level);
+  for (const ReflectionProbeData &data :
+       Span<ReflectionProbeData>(data_buf_.data(), reflection_probe_data_index_max() + 1))
+  {
+    location_finder.mark_space_used(data);
+  }
+  return location_finder.first_free_spot();
+}
+
+void ReflectionProbeModule::end_sync()
+{
+  remove_unused_probes();
+  data_buf_.push_update();
+
+#if true
+  debug_print();
+  validate();
+#endif
+
+  int number_layers_needed = needed_layers_get();
+  int current_layers = cubemaps_tx_.depth() / 6;
+  bool resize_layers = current_layers < number_layers_needed;
+  if (resize_layers) {
+    cubemaps_tx_.ensure_cube_array(GPU_RGBA16F,
+                                   MAX_RESOLUTION,
+                                   number_layers_needed,
+                                   GPU_TEXTURE_USAGE_SHADER_READ | GPU_TEXTURE_USAGE_ATTACHMENT,
+                                   NULL,
+                                   MIPMAP_LEVELS);
+  }
+
+  /* Regenerate mipmaps when a cubemap is updated. It can be postponed when the world probe is also
+   * updated. In this case it would happen as part of the WorldProbePipeline. */
+  bool regenerate_mipmaps = false;
+  bool regenerate_mipmaps_postponed = false;
+
+  for (ReflectionProbe &cubemap : cubemaps_) {
+    cubemap.is_dirty |= resize_layers;
+    if (!cubemap.needs_update()) {
+      continue;
+    }
+    sync(cubemap);
+    cubemap.is_dirty = false;
+    if (cubemap.type == ReflectionProbe::Type::WORLD) {
+      regenerate_mipmaps_postponed = true;
+    }
+    else {
+      regenerate_mipmaps = true;
+    }
+  }
+
+  if (regenerate_mipmaps) {
+    GPU_memory_barrier(GPU_BARRIER_TEXTURE_UPDATE);
+    if (!regenerate_mipmaps_postponed) {
+      GPU_texture_update_mipmap_chain(cubemaps_tx_);
+    }
+  }
+}
+
+void ReflectionProbeModule::remove_unused_probes()
+{
+  for (ReflectionProbe &probe : cubemaps_) {
+    if (probe.type == ReflectionProbe::Type::PROBE && !probe.is_used) {
+      probe.type = ReflectionProbe::Type::UNUSED;
+      probe.object_hash_value = 0;
+      BLI_assert(probe.index != -1);
+      remove_reflection_probe_data(probe.index);
+    }
+  }
+}
+
+void ReflectionProbeModule::remove_reflection_probe_data(int reflection_probe_data_index)
+{
+  int max_index = reflection_probe_data_index_max();
+  for (int index = reflection_probe_data_index; index < max_index; index++) {
+    data_buf_[index] = data_buf_[index + 1];
+  }
+  for (ReflectionProbe &probe : cubemaps_) {
+    if (probe.index == reflection_probe_data_index) {
+      probe.index = -1;
+    }
+    if (probe.index > reflection_probe_data_index) {
+      probe.index--;
+    }
+  }
+  data_buf_[max_index].layer = -1;
+  BLI_assert(reflection_probe_data_index_max() == max_index - 1);
+}
+
+void ReflectionProbeModule::debug_print() const
+{
+  std::stringstream out;
+
+  out << "\n *** " << __func__ << " ***\n";
+  for (const ReflectionProbe &probe : cubemaps_) {
+    switch (probe.type) {
+      case ReflectionProbe::Type::UNUSED: {
+        out << "UNUSED\n";
+
+        break;
+      }
+      case ReflectionProbe::Type::WORLD: {
+        out << "WORLD";
+        out << " is_dirty: " << probe.is_dirty;
+        out << " index: " << probe.index;
+        out << "\n";
+        break;
+      }
+      case ReflectionProbe::Type::PROBE: {
+        out << "PROBE";
+        out << " is_dirty: " << probe.is_dirty;
+        out << " is_used: " << probe.is_used;
+        out << " ob_hash: " << probe.object_hash_value;
+        out << " index: " << probe.index;
+        out << "\n";
+        break;
+      }
+    }
+
+    if (probe.index != -1) {
+      const ReflectionProbeData &data = data_buf_[probe.index];
+      out << " - layer: " << data.layer;
+      out << " subdivision: " << data.layer_subdivision;
+      out << " area: " << data.area_index;
+      out << "\n";
+    }
+  }
+
+  printf("%s", out.str().c_str());
+}
+
+void ReflectionProbeModule::validate() const
+{
+  for (const ReflectionProbe &probe : cubemaps_) {
+    switch (probe.type) {
+      case ReflectionProbe::Type::UNUSED: {
+        BLI_assert(probe.index == -1);
+        break;
+      }
+      case ReflectionProbe::Type::WORLD: {
+        BLI_assert(probe.index != -1);
+        break;
+      }
+      case ReflectionProbe::Type::PROBE: {
+        BLI_assert(probe.index != -1);
+        break;
+      }
+    }
+  }
+}
+
+/* -------------------------------------------------------------------- */
+/** \name World
+ *
+ * \{ */
+
+bool ReflectionProbe::needs_update() const
+{
+  switch (type) {
+    case Type::UNUSED:
+      return false;
+    case Type::WORLD:
+      return is_dirty;
+    case Type::PROBE:
+      return is_dirty && is_used;
+  }
+  return false;
+}
+
+/** \} */
+
+void ReflectionProbeModule::upload_dummy_cubemap(const ReflectionProbe &probe)
+{
+  const ReflectionProbeData &probe_data = data_buf_[probe.index];
+  const int resolution = MAX_RESOLUTION >> probe_data.layer_subdivision;
+  float4 *data = static_cast<float4 *>(
+      MEM_mallocN(sizeof(float4) * resolution * resolution, __func__));
+
+  /* Generate dummy checker pattern. */
+  int index = 0;
+  const int BLOCK_SIZE = max_ii(512 >> probe_data.layer_subdivision, 1);
+  for (int y : IndexRange(resolution)) {
+    for (int x : IndexRange(resolution)) {
+      int tx = (x / BLOCK_SIZE) & 1;
+      int ty = (y / BLOCK_SIZE) & 1;
+      bool solid = (tx + ty) & 1;
+      if (solid) {
+        data[index] = float4(probe_data.color.x, probe_data.color.y, probe_data.color.z, 1.0f);
+      }
+      else {
+        data[index] = float4(0.0f);
+      }
+
+      index++;
+    }
+  }
+
+  /* Upload the checker pattern to each side of the cubemap*/
+  int probes_per_dimension = 1 << probe_data.layer_subdivision;
+  int2 probe_area_pos(probe_data.area_index % probes_per_dimension,
+                      probe_data.area_index / probes_per_dimension);
+  int2 pos = probe_area_pos * int2(MAX_RESOLUTION / probes_per_dimension);
+  for (int side : IndexRange(6)) {
+    int layer = 6 * probe_data.layer + side;
+    GPU_texture_update_sub(
+        cubemaps_tx_, GPU_DATA_FLOAT, data, UNPACK2(pos), layer, resolution, resolution, 1);
+  }
+
+  MEM_freeN(data);
+}
+
+}  // namespace blender::eevee

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

@@ -0,0 +1,144 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later
+ * Copyright 2023 Blender Foundation. */
+
+/** \file
+ * \ingroup eevee
+ *
+ * Cubemaps
+ *
+ * Cubemaps record light from different locations in the scene. These cubemaps are used to add
+ * environment and indirect lighting from light probes.
+ *
+ * - Although we have Global illumination light probes can still be used for situations that
+ *   GI doesn't work. For example semi-transparent surfaces.
+ * - The first cubemap is always reserved for the world shading.
+ *
+ */
+
+#pragma once
+
+#include "draw_manager.hh"
+
+#include "eevee_shader_shared.hh"
+
+#include "BKE_cryptomatte.hh"
+
+extern "C" {
+struct Material;
+}
+
+namespace blender::eevee {
+
+class Instance;
+struct ObjectHandle;
+class WorldProbePipeline;
+
+/* -------------------------------------------------------------------- */
+/** \name Reflection Probes
+ * \{ */
+
+class ReflectionProbe {
+ public:
+  enum Type { UNUSED, WORLD, PROBE };
+
+  Type type = Type::UNUSED;
+  bool is_dirty = false;
+  /* When reflection probe is a probe its ObjectKey.hash_value is copied here to keep track between
+   * draws.*/
+  uint64_t object_hash_value = 0;
+
+  /**
+   * Probes that aren't used during a draw can be cleared.
+   */
+  bool is_used = false;
+
+  /**
+   * Index into ReflectionProbeDataBuf.
+   * -1 = not added yet.
+   */
+  int index = -1;
+
+  bool needs_update() const;
+};
+
+class ReflectionProbeModule {
+ private:
+  /** The max number of probes to track. */
+  static constexpr int INITIAL_PROBES = 1;
+
+  /**
+   * The maximum resolution of a cubemap side.
+   *
+   * Must be a power of two; intension to be used as a cubemap atlas.
+   */
+  static constexpr int MAX_RESOLUTION = 2048;
+  static constexpr int MIPMAP_LEVELS = 12;
+
+  /**
+   * Which subdivision level to use for storing the world/reflection probes to the cubemap.
+   * Currently set to 0 as the evaluation only supports subdivision level 0.
+   */
+  static constexpr int WORLD_SUBDIVISION_LEVEL = 0;
+  static constexpr int REFLECTION_PROBE_SUBDIVISION_LEVEL = 0;
+
+  /**
+   * Index of the probe that is used for world background.
+   *
+   * NOTE: First probe always contains the world probe.
+   */
+  static constexpr int WORLD_SLOT = 0;
+
+  Instance &instance_;
+  ReflectionProbeDataBuf data_buf_;
+  Vector<ReflectionProbe> cubemaps_;
+  Texture cubemaps_tx_ = {"Probes"};
+
+ public:
+  ReflectionProbeModule(Instance &instance) : instance_(instance) {}
+
+  void init();
+  void set_world_dirty();
+
+  void sync_object(Object *ob, ObjectHandle &ob_handle, ResourceHandle res_handle, bool is_dirty);
+  void end_sync();
+
+  template<typename T> void bind_resources(draw::detail::PassBase<T> *pass)
+  {
+    pass->bind_texture(REFLECTION_PROBE_TEX_SLOT, cubemaps_tx_);
+    pass->bind_ssbo(REFLECTION_PROBE_BUF_SLOT, data_buf_);
+  }
+
+  void debug_print() const;
+  void validate() const;
+
+ private:
+  void sync(const ReflectionProbe &cubemap);
+  ReflectionProbe &find_or_insert(ObjectHandle &ob_handle, int subdivision_level);
+
+  /** Get the number of layers that is needed to store probes. */
+  int needed_layers_get() const;
+
+  void remove_unused_probes();
+
+  /* TODO: also add _len() which is a max + 1. */
+  /* Get the number of reflection probe data elements. */
+  int reflection_probe_data_index_max() const;
+
+  /**
+   * Remove reflection probe data from the module.
+   * Ensures that data_buf is sequential and cubemaps are relinked to its corresponding data.
+   */
+  void remove_reflection_probe_data(int reflection_probe_data_index);
+
+  /**
+   * Create a reflection probe data element that points to an empty spot in the cubemap that can
+   * hold a texture with the given subdivision_level.
+   */
+  ReflectionProbeData find_empty_reflection_probe_data(int subdivision_level) const;
+
+  void upload_dummy_cubemap(const ReflectionProbe &probe);
+
+  friend class WorldProbePipeline;
+};
+
+}  // namespace blender::eevee

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

@@ -1007,6 +1007,61 @@ BLI_STATIC_ASSERT_ALIGN(SubsurfaceData, 16)
 
 /** \} */
 
+/* -------------------------------------------------------------------- */
+/** \name Reflection Probes
+ * \{ */
+
+/** Mapping data to locate a reflection probe in cubemap array texture. */
+struct ReflectionProbeData {
+  /**
+   * Dummy color of the reflection probe. Is used during development to generate a dummy reflection
+   * probe result, until baking has been implemented.
+   *
+   * This ensures that we are able to develop the reflection probe evaluation separately from
+   * baking.
+   *
+   * TODO: remove this attribute when baking has been implemented.
+   * NOTE: alpha channel is not used, but here for alignment reasons.
+   */
+  float4 color;
+  packed_float3 pos;
+
+  /**
+   * Max distance in world units that is effected by this probe. (including falloff)
+   */
+  float influence_distance;
+  /**
+   * Percentage of the radius when the falloff starts counting from the outside of the radius.
+   *
+   * 0.0: no falloff
+   * 1.0: falloff starts at the center of the reflection probe
+   */
+  float falloff;
+
+  /** On which layer of the cubemaps array is this reflection probe stored. */
+  int layer;
+
+  /**
+   * Subdivision of the layer. 0 = no subdivision and resolution would be
+   * ReflectionProbeModule::MAX_RESOLUTION.
+   *
+   * Design: technically we could fill different subdivisions in a single layer to improve packing.
+   */
+  int layer_subdivision;
+
+  /**
+   * Which area of the subdivided layer is the reflection probe located.
+   *
+   * A layer has (2^layer_subdivision)^2 areas.
+   */
+  int area_index;
+
+  // int _pad1;
+};
+BLI_STATIC_ASSERT_ALIGN(ReflectionProbeData, 16)
+
+/** \} */
+
 /* -------------------------------------------------------------------- */
 /** \name Utility Texture
  * \{ */
@@ -1063,6 +1118,8 @@ using LightCullingZdistBuf = draw::StorageArrayBuffer<float, LIGHT_CHUNK, true>;
 using LightDataBuf = draw::StorageArrayBuffer<LightData, LIGHT_CHUNK>;
 using MotionBlurDataBuf = draw::UniformBuffer<MotionBlurData>;
 using MotionBlurTileIndirectionBuf = draw::StorageBuffer<MotionBlurTileIndirection, true>;
+using ReflectionProbeDataBuf =
+    draw::StorageArrayBuffer<ReflectionProbeData, REFLECTION_PROBES_MAX>;
 using SamplingDataBuf = draw::StorageBuffer<SamplingData>;
 using ShadowStatisticsBuf = draw::StorageBuffer<ShadowStatistics>;
 using ShadowPagesInfoDataBuf = draw::StorageBuffer<ShadowPagesInfoData>;

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

@@ -289,6 +289,19 @@ void SyncModule::sync_gpencil(Object *ob, ObjectHandle &ob_handle, ResourceHandl
 
 /** \} */
 
+/* -------------------------------------------------------------------- */
+/** \name LightProbe
+ * \{ */
+
+void SyncModule::sync_light_probe(Object *ob, ObjectHandle &ob_handle, ResourceHandle res_handle)
+{
+  bool is_dirty = ob_handle.recalc;
+  inst_.reflection_probes.sync_object(ob, ob_handle, res_handle, is_dirty);
+  ob_handle.reset_recalc_flag();
+}
+
+/** \} */
+
 /* -------------------------------------------------------------------- */
 /** \name Hair
  * \{ */

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

@@ -169,6 +169,7 @@ class SyncModule {
                    ObjectHandle &ob_handle,
                    ResourceHandle res_handle,
                    ModifierData *modifier_data = nullptr);
+  void sync_light_probe(Object *ob, ObjectHandle &ob_handle, ResourceHandle res_handle);
 };
 
 /** \} */

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

@@ -118,6 +118,7 @@ void ShadingView::render()
   GPU_framebuffer_bind(combined_fb_);
   GPU_framebuffer_clear_color_depth(combined_fb_, clear_color, 1.0f);
 
+  inst_.pipelines.world_probe.render();
   inst_.pipelines.world.render(render_view_new_);
 
   /* TODO(fclem): Move it after the first prepass (and hiz update) once pipeline is stabilized. */
@@ -125,8 +126,6 @@ void ShadingView::render()
 
   inst_.pipelines.deferred.render(render_view_new_, prepass_fb_, combined_fb_, extent_);
 
-  // inst_.lightprobes.draw_cache_display();
-
   // inst_.lookdev.render_overlay(view_fb_);
 
   inst_.pipelines.forward.render(render_view_new_, prepass_fb_, combined_fb_, rbufs.combined_tx);

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

@@ -90,7 +90,7 @@ void World::sync()
   WorldHandle &wo_handle = inst_.sync.sync_world(bl_world);
 
   if (wo_handle.recalc != 0) {
-    // inst_.lightprobes.set_world_dirty();
+    inst_.reflection_probes.set_world_dirty();
   }
   wo_handle.reset_recalc_flag();
 
@@ -111,6 +111,21 @@ void World::sync()
   inst_.pipelines.world.sync(gpumat);
 }
 
+GPUMaterial *World::get_world_material()
+{
+  ::World *bl_world = inst_.scene->world;
+  if (bl_world == nullptr) {
+    bl_world = default_world_get();
+  }
+
+  bNodeTree *ntree = (bl_world->nodetree && bl_world->use_nodes) ?
+                         bl_world->nodetree :
+                         default_tree.nodetree_get(bl_world);
+
+  GPUMaterial *gpumat = inst_.shaders.world_shader_get(bl_world, ntree);
+  return gpumat;
+}
+
 /** \} */
 
 }  // namespace blender::eevee

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

@@ -62,6 +62,13 @@ class World {
   ~World();
 
   void sync();
+
+  /**
+   * Get the world material.
+   *
+   * NOTE: this function should only be called after World::sync has been executed.
+   */
+  GPUMaterial *get_world_material();
 };
 
 /** \} */

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_reflection_probe_lib.glsl)
 #pragma BLENDER_REQUIRE(eevee_lightprobe_eval_lib.glsl)
 
 void main()
@@ -55,7 +56,7 @@ void main()
   float shadow = 1.0;
 
   lightprobe_eval(diffuse_data, reflection_data, P, Ng, V, diffuse_light, reflection_light);
-
+  light_probes_eval(reflection_data, P, V, reflection_light);
   light_eval(diffuse_data,
              reflection_data,
              P,

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

@@ -0,0 +1,46 @@
+
+float4 light_probe_eval(ClosureReflection reflection, vec3 P, vec3 V, in ReflectionProbeData probe)
+{
+  float linear_roughness = fast_sqrt(reflection.roughness);
+  /* TODO: This should be based by actual resolution. Currently the resolution is fixed but
+   * eventually this should based on a user setting.
+   * (12.0 - subdivision level)
+   */
+  float lod_cube_max = 12.0;
+  float lod = linear_roughness * lod_cube_max;
+
+  vec3 R = -reflect(V, reflection.N);
+  vec4 probe_light = textureLod_cubemapArray(reflectionProbes, vec4(R, probe.layer), lod);
+  return probe_light;
+}
+
+void light_probes_eval(ClosureReflection reflection, vec3 P, vec3 V, inout vec3 out_specular)
+{
+  vec4 light = vec4(0.0);
+  float tot_weight = 0.0;
+  for (int probe_index = 1; probe_index < REFLECTION_PROBES_MAX; probe_index++) {
+    ReflectionProbeData probe_data = reflection_probe_buf[probe_index];
+    /* Probe data are tightly packed so we can break the for loop. */
+    if (probe_data.layer == -1) {
+      break;
+    }
+    /* Calculate the weight of the probe on P. */
+    /* TODO: rewrite to mix? */
+    float probe_weight = 1.0 -
+                         smoothstep(probe_data.influence_distance * (1.0 - probe_data.falloff),
+                                    probe_data.influence_distance,
+                                    length(probe_data.pos - P));
+    if (probe_weight > 0.0) {
+      vec4 probe_light = light_probe_eval(reflection, P, V, probe_data);
+      light.rgb += probe_light.rgb * probe_light.a * probe_weight;
+      light.a += probe_light.a * probe_weight;
+    }
+    tot_weight += probe_weight;
+  }
+
+  float world_mix = 1.0 - clamp(light.a, 0.0, 1.0);
+  if (world_mix > 0.0) {
+    out_specular += mix(
+        light.rgb, light_probe_eval(reflection, P, V, reflection_probe_buf[0]).rgb, world_mix);
+  }
+}

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

@@ -37,6 +37,7 @@ GPU_SHADER_CREATE_INFO(eevee_deferred_light)
     .additional_info("eevee_shared",
                      "eevee_utility_texture",
                      "eevee_light_data",
+                     "eevee_reflection_probe_data",
                      "eevee_lightprobe_data",
                      "eevee_shadow_data",
                      "eevee_deferred_base",

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

@@ -0,0 +1,18 @@
+#include "eevee_defines.hh"
+#include "gpu_shader_create_info.hh"
+
+/* -------------------------------------------------------------------- */
+/** \name Shared
+ * \{ */
+
+GPU_SHADER_CREATE_INFO(eevee_reflection_probe_world_data)
+    .sampler(REFLECTION_PROBE_TEX_SLOT, ImageType::FLOAT_CUBE_ARRAY, "reflectionProbes");
+
+GPU_SHADER_CREATE_INFO(eevee_reflection_probe_data)
+    .additional_info("eevee_reflection_probe_world_data")
+    .storage_buf(REFLECTION_PROBE_BUF_SLOT,
+                 Qualifier::READ,
+                 "ReflectionProbeData",
+                 "reflection_probe_buf[]");
+
+/** \} */

source/blender/draw/intern/DRW_gpu_wrapper.hh

@@ -691,7 +691,7 @@ class Texture : NonCopyable {
                          float *data = nullptr,
                          int mip_len = 1)
   {
-    return ensure_impl(extent, extent, layers, mip_len, format, usage, data, false, true);
+    return ensure_impl(extent, extent, layers, mip_len, format, usage, data, true, true);
   }
 
   /**

source/blender/gpu/CMakeLists.txt

@@ -651,6 +651,7 @@ set(SRC_SHADER_CREATE_INFOS
   ../draw/engines/eevee_next/shaders/infos/eevee_light_culling_info.hh
   ../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_reflection_probe_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