Eevee: Remove the Volumetric Render checkbox

This is to simplify the usage of Volumetrics.

Now it automatically detect if there is any Volumetric material in the
view and allocate the needed buffer if any.

1 files changed, 323 insertions, 298 deletions

diff --git a/source/blender/draw/engines/eevee/eevee_volumes.c b/source/blender/draw/engines/eevee/eevee_volumes.c
index 8867bf107ec..39942617d2b 100644
--- a/source/blender/draw/engines/eevee/eevee_volumes.c
+++ b/source/blender/draw/engines/eevee/eevee_volumes.c
@@ -49,8 +49,8 @@ static struct {
   char *volumetric_common_lights_lib;
 
   struct GPUShader *volumetric_clear_sh;
-  struct GPUShader *volumetric_scatter_sh;
-  struct GPUShader *volumetric_scatter_with_lights_sh;
+  struct GPUShader *scatter_sh;
+  struct GPUShader *scatter_with_lights_sh;
   struct GPUShader *volumetric_integration_sh;
   struct GPUShader *volumetric_resolve_sh;
 
@@ -60,6 +60,9 @@ static struct {
   GPUTexture *dummy_density;
   GPUTexture *dummy_flame;
 
+  GPUTexture *dummy_scatter;
+  GPUTexture *dummy_transmit;
+
   /* List of all smoke domains rendered within this frame. */
   ListBase smoke_domains;
 } e_data = {NULL}; /* Engine data */
@@ -100,22 +103,21 @@ static void eevee_create_shader_volumes(void)
                                                           e_data.volumetric_common_lib,
                                                           "#define VOLUMETRICS\n"
                                                           "#define CLEAR\n");
-  e_data.volumetric_scatter_sh = DRW_shader_create_with_lib(datatoc_volumetric_vert_glsl,
-                                                            datatoc_volumetric_geom_glsl,
-                                                            datatoc_volumetric_scatter_frag_glsl,
-                                                            e_data.volumetric_common_lights_lib,
-                                                            SHADER_DEFINES
-                                                            "#define VOLUMETRICS\n"
-                                                            "#define VOLUME_SHADOW\n");
-  e_data.volumetric_scatter_with_lights_sh = DRW_shader_create_with_lib(
-      datatoc_volumetric_vert_glsl,
-      datatoc_volumetric_geom_glsl,
-      datatoc_volumetric_scatter_frag_glsl,
-      e_data.volumetric_common_lights_lib,
-      SHADER_DEFINES
-      "#define VOLUMETRICS\n"
-      "#define VOLUME_LIGHTING\n"
-      "#define VOLUME_SHADOW\n");
+  e_data.scatter_sh = DRW_shader_create_with_lib(datatoc_volumetric_vert_glsl,
+                                                 datatoc_volumetric_geom_glsl,
+                                                 datatoc_volumetric_scatter_frag_glsl,
+                                                 e_data.volumetric_common_lights_lib,
+                                                 SHADER_DEFINES
+                                                 "#define VOLUMETRICS\n"
+                                                 "#define VOLUME_SHADOW\n");
+  e_data.scatter_with_lights_sh = DRW_shader_create_with_lib(datatoc_volumetric_vert_glsl,
+                                                             datatoc_volumetric_geom_glsl,
+                                                             datatoc_volumetric_scatter_frag_glsl,
+                                                             e_data.volumetric_common_lights_lib,
+                                                             SHADER_DEFINES
+                                                             "#define VOLUMETRICS\n"
+                                                             "#define VOLUME_LIGHTING\n"
+                                                             "#define VOLUME_SHADOW\n");
   e_data.volumetric_integration_sh = DRW_shader_create_with_lib(
       datatoc_volumetric_vert_glsl,
       datatoc_volumetric_geom_glsl,
@@ -150,7 +152,7 @@ void EEVEE_volumes_set_jitter(EEVEE_ViewLayerData *sldata, uint current_sample)
   common_data->vol_jitter[2] = (float)ht_point[2];
 }
 
-int EEVEE_volumes_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata)
+void EEVEE_volumes_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata)
 {
   EEVEE_StorageList *stl = vedata->stl;
   EEVEE_FramebufferList *fbl = vedata->fbl;
@@ -165,312 +167,207 @@ int EEVEE_volumes_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata)
 
   BLI_listbase_clear(&e_data.smoke_domains);
 
-  if (scene_eval->eevee.flag & SCE_EEVEE_VOLUMETRIC_ENABLED) {
-
-    /* Shaders */
-    if (!e_data.volumetric_scatter_sh) {
-      eevee_create_shader_volumes();
-    }
-
-    const int tile_size = scene_eval->eevee.volumetric_tile_size;
-
-    /* Find Froxel Texture resolution. */
-    int tex_size[3];
-
-    tex_size[0] = (int)ceilf(fmaxf(1.0f, viewport_size[0] / (float)tile_size));
-    tex_size[1] = (int)ceilf(fmaxf(1.0f, viewport_size[1] / (float)tile_size));
-    tex_size[2] = max_ii(scene_eval->eevee.volumetric_samples, 1);
-
-    common_data->vol_coord_scale[0] = viewport_size[0] / (float)(tile_size * tex_size[0]);
-    common_data->vol_coord_scale[1] = viewport_size[1] / (float)(tile_size * tex_size[1]);
-
-    /* TODO compute snap to maxZBuffer for clustered rendering */
-
-    if ((common_data->vol_tex_size[0] != tex_size[0]) ||
-        (common_data->vol_tex_size[1] != tex_size[1]) ||
-        (common_data->vol_tex_size[2] != tex_size[2])) {
-      DRW_TEXTURE_FREE_SAFE(txl->volume_prop_scattering);
-      DRW_TEXTURE_FREE_SAFE(txl->volume_prop_extinction);
-      DRW_TEXTURE_FREE_SAFE(txl->volume_prop_emission);
-      DRW_TEXTURE_FREE_SAFE(txl->volume_prop_phase);
-      DRW_TEXTURE_FREE_SAFE(txl->volume_scatter);
-      DRW_TEXTURE_FREE_SAFE(txl->volume_transmittance);
-      DRW_TEXTURE_FREE_SAFE(txl->volume_scatter_history);
-      DRW_TEXTURE_FREE_SAFE(txl->volume_transmittance_history);
-      GPU_FRAMEBUFFER_FREE_SAFE(fbl->volumetric_fb);
-      GPU_FRAMEBUFFER_FREE_SAFE(fbl->volumetric_scat_fb);
-      GPU_FRAMEBUFFER_FREE_SAFE(fbl->volumetric_integ_fb);
-      common_data->vol_tex_size[0] = tex_size[0];
-      common_data->vol_tex_size[1] = tex_size[1];
-      common_data->vol_tex_size[2] = tex_size[2];
-
-      common_data->vol_inv_tex_size[0] = 1.0f / (float)(tex_size[0]);
-      common_data->vol_inv_tex_size[1] = 1.0f / (float)(tex_size[1]);
-      common_data->vol_inv_tex_size[2] = 1.0f / (float)(tex_size[2]);
-    }
-
-    /* Like frostbite's paper, 5% blend of the new frame. */
-    common_data->vol_history_alpha = (txl->volume_prop_scattering == NULL) ? 0.0f : 0.95f;
-
-    if (txl->volume_prop_scattering == NULL) {
-      /* Volume properties: We evaluate all volumetric objects
-       * and store their final properties into each froxel */
-      txl->volume_prop_scattering = DRW_texture_create_3d(
-          tex_size[0], tex_size[1], tex_size[2], GPU_R11F_G11F_B10F, DRW_TEX_FILTER, NULL);
-      txl->volume_prop_extinction = DRW_texture_create_3d(
-          tex_size[0], tex_size[1], tex_size[2], GPU_R11F_G11F_B10F, DRW_TEX_FILTER, NULL);
-      txl->volume_prop_emission = DRW_texture_create_3d(
-          tex_size[0], tex_size[1], tex_size[2], GPU_R11F_G11F_B10F, DRW_TEX_FILTER, NULL);
-      txl->volume_prop_phase = DRW_texture_create_3d(
-          tex_size[0], tex_size[1], tex_size[2], GPU_RG16F, DRW_TEX_FILTER, NULL);
-
-      /* Volume scattering: We compute for each froxel the
-       * Scattered light towards the view. We also resolve temporal
-       * super sampling during this stage. */
-      txl->volume_scatter = DRW_texture_create_3d(
-          tex_size[0], tex_size[1], tex_size[2], GPU_R11F_G11F_B10F, DRW_TEX_FILTER, NULL);
-      txl->volume_transmittance = DRW_texture_create_3d(
-          tex_size[0], tex_size[1], tex_size[2], GPU_R11F_G11F_B10F, DRW_TEX_FILTER, NULL);
+  const int tile_size = scene_eval->eevee.volumetric_tile_size;
+
+  /* Find Froxel Texture resolution. */
+  int tex_size[3];
+
+  tex_size[0] = (int)ceilf(fmaxf(1.0f, viewport_size[0] / (float)tile_size));
+  tex_size[1] = (int)ceilf(fmaxf(1.0f, viewport_size[1] / (float)tile_size));
+  tex_size[2] = max_ii(scene_eval->eevee.volumetric_samples, 1);
+
+  common_data->vol_coord_scale[0] = viewport_size[0] / (float)(tile_size * tex_size[0]);
+  common_data->vol_coord_scale[1] = viewport_size[1] / (float)(tile_size * tex_size[1]);
+
+  /* TODO compute snap to maxZBuffer for clustered rendering */
+  if ((common_data->vol_tex_size[0] != tex_size[0]) ||
+      (common_data->vol_tex_size[1] != tex_size[1]) ||
+      (common_data->vol_tex_size[2] != tex_size[2])) {
+    DRW_TEXTURE_FREE_SAFE(txl->volume_prop_scattering);
+    DRW_TEXTURE_FREE_SAFE(txl->volume_prop_extinction);
+    DRW_TEXTURE_FREE_SAFE(txl->volume_prop_emission);
+    DRW_TEXTURE_FREE_SAFE(txl->volume_prop_phase);
+    DRW_TEXTURE_FREE_SAFE(txl->volume_scatter);
+    DRW_TEXTURE_FREE_SAFE(txl->volume_transmit);
+    DRW_TEXTURE_FREE_SAFE(txl->volume_scatter_history);
+    DRW_TEXTURE_FREE_SAFE(txl->volume_transmit_history);
+    GPU_FRAMEBUFFER_FREE_SAFE(fbl->volumetric_fb);
+    GPU_FRAMEBUFFER_FREE_SAFE(fbl->volumetric_scat_fb);
+    GPU_FRAMEBUFFER_FREE_SAFE(fbl->volumetric_integ_fb);
+    copy_v3_v3_int(common_data->vol_tex_size, tex_size);
+
+    common_data->vol_inv_tex_size[0] = 1.0f / (float)(tex_size[0]);
+    common_data->vol_inv_tex_size[1] = 1.0f / (float)(tex_size[1]);
+    common_data->vol_inv_tex_size[2] = 1.0f / (float)(tex_size[2]);
+  }
 
-      /* Final integration: We compute for each froxel the
-       * amount of scattered light and extinction coef at this
-       * given depth. We use theses textures as double buffer
-       * for the volumetric history. */
-      txl->volume_scatter_history = DRW_texture_create_3d(
-          tex_size[0], tex_size[1], tex_size[2], GPU_R11F_G11F_B10F, DRW_TEX_FILTER, NULL);
-      txl->volume_transmittance_history = DRW_texture_create_3d(
-          tex_size[0], tex_size[1], tex_size[2], GPU_R11F_G11F_B10F, DRW_TEX_FILTER, NULL);
-    }
+  /* Like frostbite's paper, 5% blend of the new frame. */
+  common_data->vol_history_alpha = (txl->volume_prop_scattering == NULL) ? 0.0f : 0.95f;
 
-    /* Temporal Super sampling jitter */
-    uint ht_primes[3] = {3, 7, 2};
-    uint current_sample = 0;
+  /* Temporal Super sampling jitter */
+  uint ht_primes[3] = {3, 7, 2};
+  uint current_sample = 0;
 
-    /* If TAA is in use do not use the history buffer. */
-    bool do_taa = ((effects->enabled_effects & EFFECT_TAA) != 0);
+  /* If TAA is in use do not use the history buffer. */
+  bool do_taa = ((effects->enabled_effects & EFFECT_TAA) != 0);
 
-    if (draw_ctx->evil_C != NULL) {
-      struct wmWindowManager *wm = CTX_wm_manager(draw_ctx->evil_C);
-      do_taa = do_taa && (ED_screen_animation_no_scrub(wm) == NULL);
-    }
+  if (draw_ctx->evil_C != NULL) {
+    struct wmWindowManager *wm = CTX_wm_manager(draw_ctx->evil_C);
+    do_taa = do_taa && (ED_screen_animation_no_scrub(wm) == NULL);
+  }
 
-    if (do_taa) {
-      common_data->vol_history_alpha = 0.0f;
-      current_sample = effects->taa_current_sample - 1;
-      effects->volume_current_sample = -1;
-    }
-    else {
-      const uint max_sample = (ht_primes[0] * ht_primes[1] * ht_primes[2]);
-      current_sample = effects->volume_current_sample = (effects->volume_current_sample + 1) %
-                                                        max_sample;
-      if (current_sample != max_sample - 1) {
-        DRW_viewport_request_redraw();
-      }
+  if (do_taa) {
+    common_data->vol_history_alpha = 0.0f;
+    current_sample = effects->taa_current_sample - 1;
+    effects->volume_current_sample = -1;
+  }
+  else {
+    const uint max_sample = (ht_primes[0] * ht_primes[1] * ht_primes[2]);
+    current_sample = effects->volume_current_sample = (effects->volume_current_sample + 1) %
+                                                      max_sample;
+    if (current_sample != max_sample - 1) {
+      DRW_viewport_request_redraw();
     }
+  }
 
-    EEVEE_volumes_set_jitter(sldata, current_sample);
+  EEVEE_volumes_set_jitter(sldata, current_sample);
 
-    /* Framebuffer setup */
-    GPU_framebuffer_ensure_config(&fbl->volumetric_fb,
-                                  {GPU_ATTACHMENT_NONE,
-                                   GPU_ATTACHMENT_TEXTURE(txl->volume_prop_scattering),
-                                   GPU_ATTACHMENT_TEXTURE(txl->volume_prop_extinction),
-                                   GPU_ATTACHMENT_TEXTURE(txl->volume_prop_emission),
-                                   GPU_ATTACHMENT_TEXTURE(txl->volume_prop_phase)});
-    GPU_framebuffer_ensure_config(&fbl->volumetric_scat_fb,
-                                  {GPU_ATTACHMENT_NONE,
-                                   GPU_ATTACHMENT_TEXTURE(txl->volume_scatter),
-                                   GPU_ATTACHMENT_TEXTURE(txl->volume_transmittance)});
-    GPU_framebuffer_ensure_config(&fbl->volumetric_integ_fb,
-                                  {GPU_ATTACHMENT_NONE,
-                                   GPU_ATTACHMENT_TEXTURE(txl->volume_scatter_history),
-                                   GPU_ATTACHMENT_TEXTURE(txl->volume_transmittance_history)});
-
-    float integration_start = scene_eval->eevee.volumetric_start;
-    float integration_end = scene_eval->eevee.volumetric_end;
-    common_data->vol_light_clamp = scene_eval->eevee.volumetric_light_clamp;
-    common_data->vol_shadow_steps = (float)scene_eval->eevee.volumetric_shadow_samples;
-    if ((scene_eval->eevee.flag & SCE_EEVEE_VOLUMETRIC_SHADOWS) == 0) {
-      common_data->vol_shadow_steps = 0;
-    }
+  float integration_start = scene_eval->eevee.volumetric_start;
+  float integration_end = scene_eval->eevee.volumetric_end;
+  common_data->vol_light_clamp = scene_eval->eevee.volumetric_light_clamp;
+  common_data->vol_shadow_steps = (float)scene_eval->eevee.volumetric_shadow_samples;
+  if ((scene_eval->eevee.flag & SCE_EEVEE_VOLUMETRIC_SHADOWS) == 0) {
+    common_data->vol_shadow_steps = 0;
+  }
 
-    /* Update view_vecs */
-    float invproj[4][4], winmat[4][4];
-    DRW_viewport_matrix_get(winmat, DRW_MAT_WIN);
-    DRW_viewport_matrix_get(invproj, DRW_MAT_WININV);
-    EEVEE_update_viewvecs(invproj, winmat, sldata->common_data.view_vecs);
-
-    if (DRW_viewport_is_persp_get()) {
-      float sample_distribution = scene_eval->eevee.volumetric_sample_distribution;
-      sample_distribution = 4.0f * (1.00001f - sample_distribution);
-
-      const float clip_start = common_data->view_vecs[0][2];
-      /* Negate */
-      float near = integration_start = min_ff(-integration_start, clip_start - 1e-4f);
-      float far = integration_end = min_ff(-integration_end, near - 1e-4f);
-
-      common_data->vol_depth_param[0] = (far - near * exp2(1.0f / sample_distribution)) /
-                                        (far - near);
-      common_data->vol_depth_param[1] = (1.0f - common_data->vol_depth_param[0]) / near;
-      common_data->vol_depth_param[2] = sample_distribution;
-    }
-    else {
-      const float clip_start = common_data->view_vecs[0][2];
-      const float clip_end = clip_start + common_data->view_vecs[1][2];
-      integration_start = min_ff(integration_end, clip_start);
-      integration_end = max_ff(-integration_end, clip_end);
-
-      common_data->vol_depth_param[0] = integration_start;
-      common_data->vol_depth_param[1] = integration_end;
-      common_data->vol_depth_param[2] = 1.0f / (integration_end - integration_start);
-    }
+  /* Update view_vecs */
+  float invproj[4][4], winmat[4][4];
+  DRW_viewport_matrix_get(winmat, DRW_MAT_WIN);
+  DRW_viewport_matrix_get(invproj, DRW_MAT_WININV);
+  EEVEE_update_viewvecs(invproj, winmat, sldata->common_data.view_vecs);
+
+  if (DRW_viewport_is_persp_get()) {
+    float sample_distribution = scene_eval->eevee.volumetric_sample_distribution;
+    sample_distribution = 4.0f * (1.00001f - sample_distribution);
+
+    const float clip_start = common_data->view_vecs[0][2];
+    /* Negate */
+    float near = integration_start = min_ff(-integration_start, clip_start - 1e-4f);
+    float far = integration_end = min_ff(-integration_end, near - 1e-4f);
+
+    common_data->vol_depth_param[0] = (far - near * exp2(1.0f / sample_distribution)) /
+                                      (far - near);
+    common_data->vol_depth_param[1] = (1.0f - common_data->vol_depth_param[0]) / near;
+    common_data->vol_depth_param[2] = sample_distribution;
+  }
+  else {
+    const float clip_start = common_data->view_vecs[0][2];
+    const float clip_end = clip_start + common_data->view_vecs[1][2];
+    integration_start = min_ff(integration_end, clip_start);
+    integration_end = max_ff(-integration_end, clip_end);
+
+    common_data->vol_depth_param[0] = integration_start;
+    common_data->vol_depth_param[1] = integration_end;
+    common_data->vol_depth_param[2] = 1.0f / (integration_end - integration_start);
+  }
 
-    /* Disable clamp if equal to 0. */
-    if (common_data->vol_light_clamp == 0.0) {
-      common_data->vol_light_clamp = FLT_MAX;
-    }
+  /* Disable clamp if equal to 0. */
+  if (common_data->vol_light_clamp == 0.0) {
+    common_data->vol_light_clamp = FLT_MAX;
+  }
 
-    common_data->vol_use_lights = (scene_eval->eevee.flag & SCE_EEVEE_VOLUMETRIC_LIGHTS) != 0;
+  common_data->vol_use_lights = (scene_eval->eevee.flag & SCE_EEVEE_VOLUMETRIC_LIGHTS) != 0;
 
-    return EFFECT_VOLUMETRIC | EFFECT_POST_BUFFER;
+  if (!e_data.dummy_scatter) {
+    float scatter[4] = {0.0f, 0.0f, 0.0f, 0.0f};
+    float transmit[4] = {1.0f, 1.0f, 1.0f, 1.0f};
+    e_data.dummy_scatter = DRW_texture_create_3d(1, 1, 1, GPU_RGBA8, DRW_TEX_WRAP, scatter);
+    e_data.dummy_transmit = DRW_texture_create_3d(1, 1, 1, GPU_RGBA8, DRW_TEX_WRAP, transmit);
   }
-
-  /* Cleanup to release memory */
-  DRW_TEXTURE_FREE_SAFE(txl->volume_prop_scattering);
-  DRW_TEXTURE_FREE_SAFE(txl->volume_prop_extinction);
-  DRW_TEXTURE_FREE_SAFE(txl->volume_prop_emission);
-  DRW_TEXTURE_FREE_SAFE(txl->volume_prop_phase);
-  DRW_TEXTURE_FREE_SAFE(txl->volume_scatter);
-  DRW_TEXTURE_FREE_SAFE(txl->volume_transmittance);
-  DRW_TEXTURE_FREE_SAFE(txl->volume_scatter_history);
-  DRW_TEXTURE_FREE_SAFE(txl->volume_transmittance_history);
-  GPU_FRAMEBUFFER_FREE_SAFE(fbl->volumetric_fb);
-  GPU_FRAMEBUFFER_FREE_SAFE(fbl->volumetric_scat_fb);
-  GPU_FRAMEBUFFER_FREE_SAFE(fbl->volumetric_integ_fb);
-
-  return 0;
 }
 
 void EEVEE_volumes_cache_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata)
 {
   EEVEE_PassList *psl = vedata->psl;
   EEVEE_StorageList *stl = vedata->stl;
-  EEVEE_TextureList *txl = vedata->txl;
   EEVEE_EffectsInfo *effects = stl->effects;
-  LightCache *lcache = stl->g_data->light_cache;
   EEVEE_CommonUniformBuffer *common_data = &sldata->common_data;
 
-  if ((effects->enabled_effects & EFFECT_VOLUMETRIC) != 0) {
-    const DRWContextState *draw_ctx = DRW_context_state_get();
-    Scene *scene = draw_ctx->scene;
-    DRWShadingGroup *grp = NULL;
-
-    /* Quick breakdown of the Volumetric rendering:
-     *
-     * The rendering is separated in 4 stages:
-     *
-     * - Material Parameters : we collect volume properties of
-     *   all participating media in the scene and store them in
-     *   a 3D texture aligned with the 3D frustum.
-     *   This is done in 2 passes, one that clear the texture
-     *   and/or evaluate the world volumes, and the 2nd one that
-     *   additively render object volumes.
-     *
-     * - Light Scattering : the volume properties then are sampled
-     *   and light scattering is evaluated for each cell of the
-     *   volume texture. Temporal super-sampling (if enabled) occurs here.
-     *
-     * - Volume Integration : the scattered light and extinction is
-     *   integrated (accumulated) along the view-rays. The result is stored
-     *   for every cell in another texture.
-     *
-     * - Full-screen Resolve : From the previous stage, we get two
-     *   3D textures that contains integrated scattered light and extinction
-     *   for "every" positions in the frustum. We only need to sample
-     *   them and blend the scene color with those factors. This also
-     *   work for alpha blended materials.
-     */
-
-    /* World pass is not additive as it also clear the buffer. */
-    psl->volumetric_world_ps = DRW_pass_create("Volumetric World", DRW_STATE_WRITE_COLOR);
-
-    /* World Volumetric */
-    struct World *wo = scene->world;
-    if (wo != NULL && wo->use_nodes && wo->nodetree &&
-        !LOOK_DEV_STUDIO_LIGHT_ENABLED(draw_ctx->v3d)) {
-      struct GPUMaterial *mat = EEVEE_material_world_volume_get(scene, wo);
+  const DRWContextState *draw_ctx = DRW_context_state_get();
+  Scene *scene = draw_ctx->scene;
+  DRWShadingGroup *grp = NULL;
 
-      grp = DRW_shgroup_material_create(mat, psl->volumetric_world_ps);
+  /* Shaders */
+  if (!e_data.scatter_sh) {
+    eevee_create_shader_volumes();
+  }
 
-      if (grp) {
-        DRW_shgroup_uniform_block(grp, "common_block", sldata->common_ubo);
-        /* TODO (fclem): remove those (need to clean the GLSL files). */
-        DRW_shgroup_uniform_block(grp, "grid_block", sldata->grid_ubo);
-        DRW_shgroup_uniform_block(grp, "probe_block", sldata->probe_ubo);
-        DRW_shgroup_uniform_block(grp, "planar_block", sldata->planar_ubo);
-        DRW_shgroup_uniform_block(grp, "light_block", sldata->light_ubo);
-        DRW_shgroup_uniform_block(grp, "shadow_block", sldata->shadow_ubo);
-
-        /* Fix principle volumetric not working with world materials. */
-        DRW_shgroup_uniform_texture(grp, "sampdensity", e_data.dummy_density);
-        DRW_shgroup_uniform_texture(grp, "sampflame", e_data.dummy_flame);
-        DRW_shgroup_uniform_vec2(grp, "unftemperature", (float[2]){0.0f, 1.0f}, 1);
-
-        DRW_shgroup_call_procedural_triangles(grp, common_data->vol_tex_size[2], NULL);
-      }
+  /* Quick breakdown of the Volumetric rendering:
+   *
+   * The rendering is separated in 4 stages:
+   *
+   * - Material Parameters : we collect volume properties of
+   *   all participating media in the scene and store them in
+   *   a 3D texture aligned with the 3D frustum.
+   *   This is done in 2 passes, one that clear the texture
+   *   and/or evaluate the world volumes, and the 2nd one that
+   *   additively render object volumes.
+   *
+   * - Light Scattering : the volume properties then are sampled
+   *   and light scattering is evaluated for each cell of the
+   *   volume texture. Temporal super-sampling (if enabled) occurs here.
+   *
+   * - Volume Integration : the scattered light and extinction is
+   *   integrated (accumulated) along the view-rays. The result is stored
+   *   for every cell in another texture.
+   *
+   * - Full-screen Resolve : From the previous stage, we get two
+   *   3D textures that contains integrated scattered light and extinction
+   *   for "every" positions in the frustum. We only need to sample
+   *   them and blend the scene color with those factors. This also
+   *   work for alpha blended materials.
+   */
+
+  /* World pass is not additive as it also clear the buffer. */
+  DRW_PASS_CREATE(psl->volumetric_world_ps, DRW_STATE_WRITE_COLOR);
+  DRW_PASS_CREATE(psl->volumetric_objects_ps, DRW_STATE_WRITE_COLOR | DRW_STATE_ADDITIVE);
+
+  /* World Volumetric */
+  struct World *wo = scene->world;
+  if (wo != NULL && wo->use_nodes && wo->nodetree &&
+      !LOOK_DEV_STUDIO_LIGHT_ENABLED(draw_ctx->v3d)) {
+    struct GPUMaterial *mat = EEVEE_material_world_volume_get(scene, wo);
+
+    if (GPU_material_use_domain_volume(mat)) {
+      grp = DRW_shgroup_material_create(mat, psl->volumetric_world_ps);
     }
 
-    if (grp == NULL) {
-      /* If no world or volume material is present just clear the buffer with this drawcall */
-      grp = DRW_shgroup_create(e_data.volumetric_clear_sh, psl->volumetric_world_ps);
-
+    if (grp) {
       DRW_shgroup_uniform_block(grp, "common_block", sldata->common_ubo);
+      /* TODO (fclem): remove those (need to clean the GLSL files). */
+      DRW_shgroup_uniform_block(grp, "grid_block", sldata->grid_ubo);
+      DRW_shgroup_uniform_block(grp, "probe_block", sldata->probe_ubo);
+      DRW_shgroup_uniform_block(grp, "planar_block", sldata->planar_ubo);
+      DRW_shgroup_uniform_block(grp, "light_block", sldata->light_ubo);
+      DRW_shgroup_uniform_block(grp, "shadow_block", sldata->shadow_ubo);
+
+      /* Fix principle volumetric not working with world materials. */
+      DRW_shgroup_uniform_texture(grp, "sampdensity", e_data.dummy_density);
+      DRW_shgroup_uniform_texture(grp, "sampflame", e_data.dummy_flame);
+      DRW_shgroup_uniform_vec2_copy(grp, "unftemperature", (float[2]){0.0f, 1.0f});
 
       DRW_shgroup_call_procedural_triangles(grp, common_data->vol_tex_size[2], NULL);
-    }
-
-    /* Volumetric Objects */
-    psl->volumetric_objects_ps = DRW_pass_create("Volumetric Properties",
-                                                 DRW_STATE_WRITE_COLOR | DRW_STATE_ADDITIVE);
-
-    struct GPUShader *scatter_sh = (common_data->vol_use_lights) ?
-                                       e_data.volumetric_scatter_with_lights_sh :
-                                       e_data.volumetric_scatter_sh;
-    psl->volumetric_scatter_ps = DRW_pass_create("Volumetric Scattering", DRW_STATE_WRITE_COLOR);
-    grp = DRW_shgroup_create(scatter_sh, psl->volumetric_scatter_ps);
-    DRW_shgroup_uniform_texture_ref(grp, "irradianceGrid", &lcache->grid_tx.tex);
-    DRW_shgroup_uniform_texture_ref(grp, "shadowCubeTexture", &sldata->shadow_cube_pool);
-    DRW_shgroup_uniform_texture_ref(grp, "shadowCascadeTexture", &sldata->shadow_cascade_pool);
-    DRW_shgroup_uniform_texture_ref(grp, "volumeScattering", &txl->volume_prop_scattering);
-    DRW_shgroup_uniform_texture_ref(grp, "volumeExtinction", &txl->volume_prop_extinction);
-    DRW_shgroup_uniform_texture_ref(grp, "volumeEmission", &txl->volume_prop_emission);
-    DRW_shgroup_uniform_texture_ref(grp, "volumePhase", &txl->volume_prop_phase);
-    DRW_shgroup_uniform_texture_ref(grp, "historyScattering", &txl->volume_scatter_history);
-    DRW_shgroup_uniform_texture_ref(
-        grp, "historyTransmittance", &txl->volume_transmittance_history);
-    DRW_shgroup_uniform_block(grp, "light_block", sldata->light_ubo);
-    DRW_shgroup_uniform_block(grp, "shadow_block", sldata->shadow_ubo);
-    DRW_shgroup_uniform_block(grp, "common_block", sldata->common_ubo);
 
-    DRW_shgroup_call_procedural_triangles(grp, common_data->vol_tex_size[2], NULL);
+      effects->enabled_effects |= (EFFECT_VOLUMETRIC | EFFECT_POST_BUFFER);
+    }
+  }
 
-    psl->volumetric_integration_ps = DRW_pass_create("Volumetric Integration",
-                                                     DRW_STATE_WRITE_COLOR);
-    grp = DRW_shgroup_create(e_data.volumetric_integration_sh, psl->volumetric_integration_ps);
-    DRW_shgroup_uniform_texture_ref(grp, "volumeScattering", &txl->volume_scatter);
-    DRW_shgroup_uniform_texture_ref(grp, "volumeExtinction", &txl->volume_transmittance);
+  if (grp == NULL) {
+    /* If no world or volume material is present just clear the buffer with this drawcall */
+    grp = DRW_shgroup_create(e_data.volumetric_clear_sh, psl->volumetric_world_ps);
     DRW_shgroup_uniform_block(grp, "common_block", sldata->common_ubo);
 
     DRW_shgroup_call_procedural_triangles(grp, common_data->vol_tex_size[2], NULL);
-
-    psl->volumetric_resolve_ps = DRW_pass_create("Volumetric Resolve", DRW_STATE_WRITE_COLOR);
-    grp = DRW_shgroup_create(e_data.volumetric_resolve_sh, psl->volumetric_resolve_ps);
-    DRW_shgroup_uniform_texture_ref(grp, "inScattering", &txl->volume_scatter);
-    DRW_shgroup_uniform_texture_ref(grp, "inTransmittance", &txl->volume_transmittance);
-    DRW_shgroup_uniform_texture_ref(grp, "inSceneColor", &e_data.color_src);
-    DRW_shgroup_uniform_texture_ref(grp, "inSceneDepth", &e_data.depth_src);
-    DRW_shgroup_uniform_block(grp, "common_block", sldata->common_ubo);
-    DRW_shgroup_call(grp, DRW_cache_fullscreen_quad_get(), NULL);
   }
 }
 
@@ -581,6 +478,135 @@ void EEVEE_volumes_cache_object_add(EEVEE_ViewLayerData *sldata,
   /* TODO Reduce to number of slices intersecting. */
   /* TODO Preemptive culling. */
   DRW_shgroup_call_procedural_triangles(grp, sldata->common_data.vol_tex_size[2], NULL);
+
+  vedata->stl->effects->enabled_effects |= (EFFECT_VOLUMETRIC | EFFECT_POST_BUFFER);
+}
+
+void EEVEE_volumes_cache_finish(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata)
+{
+  EEVEE_PassList *psl = vedata->psl;
+  EEVEE_TextureList *txl = vedata->txl;
+  EEVEE_EffectsInfo *effects = vedata->stl->effects;
+  LightCache *lcache = vedata->stl->g_data->light_cache;
+  EEVEE_CommonUniformBuffer *common_data = &sldata->common_data;
+
+  if ((effects->enabled_effects & EFFECT_VOLUMETRIC) != 0) {
+    DRWShadingGroup *grp;
+    struct GPUShader *sh;
+
+    DRW_PASS_CREATE(psl->volumetric_scatter_ps, DRW_STATE_WRITE_COLOR);
+    sh = (common_data->vol_use_lights) ? e_data.scatter_with_lights_sh : e_data.scatter_sh;
+    grp = DRW_shgroup_create(sh, psl->volumetric_scatter_ps);
+    DRW_shgroup_uniform_texture_ref(grp, "irradianceGrid", &lcache->grid_tx.tex);
+    DRW_shgroup_uniform_texture_ref(grp, "shadowCubeTexture", &sldata->shadow_cube_pool);
+    DRW_shgroup_uniform_texture_ref(grp, "shadowCascadeTexture", &sldata->shadow_cascade_pool);
+    DRW_shgroup_uniform_texture_ref(grp, "volumeScattering", &txl->volume_prop_scattering);
+    DRW_shgroup_uniform_texture_ref(grp, "volumeExtinction", &txl->volume_prop_extinction);
+    DRW_shgroup_uniform_texture_ref(grp, "volumeEmission", &txl->volume_prop_emission);
+    DRW_shgroup_uniform_texture_ref(grp, "volumePhase", &txl->volume_prop_phase);
+    DRW_shgroup_uniform_texture_ref(grp, "historyScattering", &txl->volume_scatter_history);
+    DRW_shgroup_uniform_texture_ref(grp, "historyTransmittance", &txl->volume_transmit_history);
+    DRW_shgroup_uniform_block(grp, "light_block", sldata->light_ubo);
+    DRW_shgroup_uniform_block(grp, "shadow_block", sldata->shadow_ubo);
+    DRW_shgroup_uniform_block(grp, "common_block", sldata->common_ubo);
+
+    DRW_shgroup_call_procedural_triangles(grp, common_data->vol_tex_size[2], NULL);
+
+    DRW_PASS_CREATE(psl->volumetric_integration_ps, DRW_STATE_WRITE_COLOR);
+    grp = DRW_shgroup_create(e_data.volumetric_integration_sh, psl->volumetric_integration_ps);
+    DRW_shgroup_uniform_texture_ref(grp, "volumeScattering", &txl->volume_scatter);
+    DRW_shgroup_uniform_texture_ref(grp, "volumeExtinction", &txl->volume_transmit);
+    DRW_shgroup_uniform_block(grp, "common_block", sldata->common_ubo);
+
+    DRW_shgroup_call_procedural_triangles(grp, common_data->vol_tex_size[2], NULL);
+
+    DRW_PASS_CREATE(psl->volumetric_resolve_ps, DRW_STATE_WRITE_COLOR);
+    grp = DRW_shgroup_create(e_data.volumetric_resolve_sh, psl->volumetric_resolve_ps);
+    DRW_shgroup_uniform_texture_ref(grp, "inScattering", &txl->volume_scatter);
+    DRW_shgroup_uniform_texture_ref(grp, "inTransmittance", &txl->volume_transmit);
+    DRW_shgroup_uniform_texture_ref(grp, "inSceneColor", &e_data.color_src);
+    DRW_shgroup_uniform_texture_ref(grp, "inSceneDepth", &e_data.depth_src);
+    DRW_shgroup_uniform_block(grp, "common_block", sldata->common_ubo);
+
+    DRW_shgroup_call_procedural_triangles(grp, 1, NULL);
+  }
+}
+
+void EEVEE_volumes_draw_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata)
+{
+  EEVEE_FramebufferList *fbl = vedata->fbl;
+  EEVEE_TextureList *txl = vedata->txl;
+  EEVEE_EffectsInfo *effects = vedata->stl->effects;
+  EEVEE_CommonUniformBuffer *common_data = &sldata->common_data;
+
+  if ((effects->enabled_effects & EFFECT_VOLUMETRIC) != 0) {
+    int *tex_size = common_data->vol_tex_size;
+
+    if (txl->volume_prop_scattering == NULL) {
+      /* Volume properties: We evaluate all volumetric objects
+       * and store their final properties into each froxel */
+      txl->volume_prop_scattering = DRW_texture_create_3d(
+          tex_size[0], tex_size[1], tex_size[2], GPU_R11F_G11F_B10F, DRW_TEX_FILTER, NULL);
+      txl->volume_prop_extinction = DRW_texture_create_3d(
+          tex_size[0], tex_size[1], tex_size[2], GPU_R11F_G11F_B10F, DRW_TEX_FILTER, NULL);
+      txl->volume_prop_emission = DRW_texture_create_3d(
+          tex_size[0], tex_size[1], tex_size[2], GPU_R11F_G11F_B10F, DRW_TEX_FILTER, NULL);
+      txl->volume_prop_phase = DRW_texture_create_3d(
+          tex_size[0], tex_size[1], tex_size[2], GPU_RG16F, DRW_TEX_FILTER, NULL);
+
+      /* Volume scattering: We compute for each froxel the
+       * Scattered light towards the view. We also resolve temporal
+       * super sampling during this stage. */
+      txl->volume_scatter = DRW_texture_create_3d(
+          tex_size[0], tex_size[1], tex_size[2], GPU_R11F_G11F_B10F, DRW_TEX_FILTER, NULL);
+      txl->volume_transmit = DRW_texture_create_3d(
+          tex_size[0], tex_size[1], tex_size[2], GPU_R11F_G11F_B10F, DRW_TEX_FILTER, NULL);
+
+      /* Final integration: We compute for each froxel the
+       * amount of scattered light and extinction coef at this
+       * given depth. We use theses textures as double buffer
+       * for the volumetric history. */
+      txl->volume_scatter_history = DRW_texture_create_3d(
+          tex_size[0], tex_size[1], tex_size[2], GPU_R11F_G11F_B10F, DRW_TEX_FILTER, NULL);
+      txl->volume_transmit_history = DRW_texture_create_3d(
+          tex_size[0], tex_size[1], tex_size[2], GPU_R11F_G11F_B10F, DRW_TEX_FILTER, NULL);
+    }
+
+    GPU_framebuffer_ensure_config(&fbl->volumetric_fb,
+                                  {GPU_ATTACHMENT_NONE,
+                                   GPU_ATTACHMENT_TEXTURE(txl->volume_prop_scattering),
+                                   GPU_ATTACHMENT_TEXTURE(txl->volume_prop_extinction),
+                                   GPU_ATTACHMENT_TEXTURE(txl->volume_prop_emission),
+                                   GPU_ATTACHMENT_TEXTURE(txl->volume_prop_phase)});
+    GPU_framebuffer_ensure_config(&fbl->volumetric_scat_fb,
+                                  {GPU_ATTACHMENT_NONE,
+                                   GPU_ATTACHMENT_TEXTURE(txl->volume_scatter),
+                                   GPU_ATTACHMENT_TEXTURE(txl->volume_transmit)});
+    GPU_framebuffer_ensure_config(&fbl->volumetric_integ_fb,
+                                  {GPU_ATTACHMENT_NONE,
+                                   GPU_ATTACHMENT_TEXTURE(txl->volume_scatter_history),
+                                   GPU_ATTACHMENT_TEXTURE(txl->volume_transmit_history)});
+
+    /* Usage happens after buffer have been swapped. */
+    effects->volume_scatter = txl->volume_scatter_history;
+    effects->volume_transmit = txl->volume_transmit_history;
+  }
+  else {
+    DRW_TEXTURE_FREE_SAFE(txl->volume_prop_scattering);
+    DRW_TEXTURE_FREE_SAFE(txl->volume_prop_extinction);
+    DRW_TEXTURE_FREE_SAFE(txl->volume_prop_emission);
+    DRW_TEXTURE_FREE_SAFE(txl->volume_prop_phase);
+    DRW_TEXTURE_FREE_SAFE(txl->volume_scatter);
+    DRW_TEXTURE_FREE_SAFE(txl->volume_transmit);
+    DRW_TEXTURE_FREE_SAFE(txl->volume_scatter_history);
+    DRW_TEXTURE_FREE_SAFE(txl->volume_transmit_history);
+    GPU_FRAMEBUFFER_FREE_SAFE(fbl->volumetric_fb);
+    GPU_FRAMEBUFFER_FREE_SAFE(fbl->volumetric_scat_fb);
+    GPU_FRAMEBUFFER_FREE_SAFE(fbl->volumetric_integ_fb);
+
+    effects->volume_scatter = e_data.dummy_scatter;
+    effects->volume_transmit = e_data.dummy_transmit;
+  }
 }
 
 void EEVEE_volumes_compute(EEVEE_ViewLayerData *UNUSED(sldata), EEVEE_Data *vedata)
@@ -593,23 +619,19 @@ void EEVEE_volumes_compute(EEVEE_ViewLayerData *UNUSED(sldata), EEVEE_Data *veda
   if ((effects->enabled_effects & EFFECT_VOLUMETRIC) != 0) {
     DRW_stats_group_start("Volumetrics");
 
-    /* Step 1: Participating Media Properties */
     GPU_framebuffer_bind(fbl->volumetric_fb);
     DRW_draw_pass(psl->volumetric_world_ps);
     DRW_draw_pass(psl->volumetric_objects_ps);
 
-    /* Step 2: Scatter Light */
     GPU_framebuffer_bind(fbl->volumetric_scat_fb);
     DRW_draw_pass(psl->volumetric_scatter_ps);
 
-    /* Step 3: Integration */
     GPU_framebuffer_bind(fbl->volumetric_integ_fb);
     DRW_draw_pass(psl->volumetric_integration_ps);
 
-    /* Swap volume history buffers */
     SWAP(struct GPUFrameBuffer *, fbl->volumetric_scat_fb, fbl->volumetric_integ_fb);
     SWAP(GPUTexture *, txl->volume_scatter, txl->volume_scatter_history);
-    SWAP(GPUTexture *, txl->volume_transmittance, txl->volume_transmittance_history);
+    SWAP(GPUTexture *, txl->volume_transmit, txl->volume_transmit_history);
 
     /* Restore */
     GPU_framebuffer_bind(fbl->main_fb);
@@ -663,12 +685,15 @@ void EEVEE_volumes_free(void)
   MEM_SAFE_FREE(e_data.volumetric_common_lib);
   MEM_SAFE_FREE(e_data.volumetric_common_lights_lib);
 
+  DRW_TEXTURE_FREE_SAFE(e_data.dummy_scatter);
+  DRW_TEXTURE_FREE_SAFE(e_data.dummy_transmit);
+
   DRW_TEXTURE_FREE_SAFE(e_data.dummy_density);
   DRW_TEXTURE_FREE_SAFE(e_data.dummy_flame);
 
   DRW_SHADER_FREE_SAFE(e_data.volumetric_clear_sh);
-  DRW_SHADER_FREE_SAFE(e_data.volumetric_scatter_sh);
-  DRW_SHADER_FREE_SAFE(e_data.volumetric_scatter_with_lights_sh);
+  DRW_SHADER_FREE_SAFE(e_data.scatter_sh);
+  DRW_SHADER_FREE_SAFE(e_data.scatter_with_lights_sh);
   DRW_SHADER_FREE_SAFE(e_data.volumetric_integration_sh);
   DRW_SHADER_FREE_SAFE(e_data.volumetric_resolve_sh);
 }