EEEVEE: Object Motion Blur: Initial Implementation

This adds object motion blur vectors for EEVEE as well as better noise
reduction for it.

For TAA reprojection we just compute the motion vector on the fly based on
camera motion and depth buffer. This makes possible to store another motion
vector only for the blurring which is not useful for TAA history fetching.

Motion Data is saved per object & per geometry if using deformation blur.
We support deformation motion blur by saving previous VBO and modifying the
actual GPUBatch for the geometry to include theses VBOs.

We store Previous and Next frame motion in the same motion vector buffer
(RG for prev and BA for next). This makes non linear motion blur (like
rotating objects) less prone to outward/inward blur.

We also improve the motion blur post process to expand outside the objects
border. We use a tile base approach and the max size of the blur is set via
a new render setting.

We use a background reconstruction method that needs another setting
(Background Separation).

Sampling is done using a fixed 8 dithered samples per direction. The final
render samples will clear the noise like other stochastic effects.

One caveat is that hair particles are not yet supported. Support will
come in another patch.

Reviewed By: jbakker

Differential Revision: https://developer.blender.org/D7297

1 files changed, 312 insertions, 114 deletions

diff --git a/source/blender/draw/engines/eevee/eevee_motion_blur.c b/source/blender/draw/engines/eevee/eevee_motion_blur.c
index a6e6b30a6b1..b90d575b80c 100644
--- a/source/blender/draw/engines/eevee/eevee_motion_blur.c
+++ b/source/blender/draw/engines/eevee/eevee_motion_blur.c
@@ -24,12 +24,16 @@
 
 #include "DRW_render.h"
 
+#include "BLI_rand.h"
+
 #include "BKE_animsys.h"
 #include "BKE_camera.h"
 #include "BKE_object.h"
+#include "BKE_screen.h"
 
 #include "DNA_anim_types.h"
 #include "DNA_camera_types.h"
+#include "DNA_mesh_types.h"
 #include "DNA_screen_types.h"
 
 #include "ED_screen.h"
@@ -37,172 +41,333 @@
 #include "DEG_depsgraph.h"
 #include "DEG_depsgraph_query.h"
 
+#include "GPU_batch.h"
 #include "GPU_texture.h"
 #include "eevee_private.h"
 
 static struct {
   /* Motion Blur */
   struct GPUShader *motion_blur_sh;
+  struct GPUShader *motion_blur_object_sh;
+  struct GPUShader *velocity_tiles_sh;
+  struct GPUShader *velocity_tiles_expand_sh;
 } e_data = {NULL}; /* Engine data */
 
+extern char datatoc_effect_velocity_tile_frag_glsl[];
 extern char datatoc_effect_motion_blur_frag_glsl[];
+extern char datatoc_object_motion_frag_glsl[];
+extern char datatoc_object_motion_vert_glsl[];
+extern char datatoc_common_view_lib_glsl[];
 
-static void eevee_motion_blur_camera_get_matrix_at_time(Scene *scene,
-                                                        ARegion *region,
-                                                        RegionView3D *rv3d,
-                                                        View3D *v3d,
-                                                        Object *camera,
-                                                        float time,
-                                                        float r_mat[4][4])
-{
-  float obmat[4][4];
+#define EEVEE_VELOCITY_TILE_SIZE 32
 
-  /* HACK */
-  Object cam_cpy = *camera;
-  Camera camdata_cpy = *(Camera *)(camera->data);
-  cam_cpy.data = &camdata_cpy;
+static void eevee_create_shader_motion_blur(void)
+{
+  e_data.motion_blur_sh = DRW_shader_create_fullscreen(
+      datatoc_effect_motion_blur_frag_glsl,
+      "#define EEVEE_VELOCITY_TILE_SIZE " STRINGIFY(EEVEE_VELOCITY_TILE_SIZE) "\n");
+  e_data.motion_blur_object_sh = DRW_shader_create_with_lib(datatoc_object_motion_vert_glsl,
+                                                            NULL,
+                                                            datatoc_object_motion_frag_glsl,
+                                                            datatoc_common_view_lib_glsl,
+                                                            NULL);
+  e_data.velocity_tiles_sh = DRW_shader_create_fullscreen(
+      datatoc_effect_velocity_tile_frag_glsl,
+      "#define TILE_GATHER\n"
+      "#define EEVEE_VELOCITY_TILE_SIZE " STRINGIFY(EEVEE_VELOCITY_TILE_SIZE) "\n");
+  e_data.velocity_tiles_expand_sh = DRW_shader_create_fullscreen(
+      datatoc_effect_velocity_tile_frag_glsl,
+      "#define TILE_EXPANSION\n"
+      "#define EEVEE_VELOCITY_TILE_SIZE " STRINGIFY(EEVEE_VELOCITY_TILE_SIZE) "\n");
+}
 
-  /* Reset original pointers, so direct evaluation does not attempt to flush
-   * animation back to the original object: otherwise viewport with motion
-   * blur enabled will always loose non-keyed changes. */
-  cam_cpy.id.orig_id = NULL;
-  camdata_cpy.id.orig_id = NULL;
+int EEVEE_motion_blur_init(EEVEE_ViewLayerData *UNUSED(sldata), EEVEE_Data *vedata, Object *camera)
+{
+  EEVEE_StorageList *stl = vedata->stl;
+  EEVEE_FramebufferList *fbl = vedata->fbl;
+  EEVEE_EffectsInfo *effects = stl->effects;
 
   const DRWContextState *draw_ctx = DRW_context_state_get();
+  Scene *scene = draw_ctx->scene;
 
-  /* Past matrix */
-  /* FIXME : This is a temporal solution that does not take care of parent animations */
-  /* Recalc Anim manually */
-  BKE_animsys_evaluate_animdata(&camdata_cpy.id, camdata_cpy.adt, time, ADT_RECALC_ALL, false);
-  BKE_object_where_is_calc_time(draw_ctx->depsgraph, scene, &cam_cpy, time);
+  /* Viewport not supported for now. */
+  if (!DRW_state_is_scene_render()) {
+    return 0;
+  }
 
-  /* Compute winmat */
-  CameraParams params;
-  BKE_camera_params_init(&params);
+  if (scene->eevee.flag & SCE_EEVEE_MOTION_BLUR_ENABLED) {
+    if (!e_data.motion_blur_sh) {
+      eevee_create_shader_motion_blur();
+    }
 
-  if (v3d != NULL) {
-    BKE_camera_params_from_view3d(&params, draw_ctx->depsgraph, v3d, rv3d);
-    BKE_camera_params_compute_viewplane(&params, region->winx, region->winy, 1.0f, 1.0f);
-  }
-  else {
-    BKE_camera_params_from_object(&params, &cam_cpy);
-    BKE_camera_params_compute_viewplane(
-        &params, scene->r.xsch, scene->r.ysch, scene->r.xasp, scene->r.yasp);
-  }
+    if (DRW_state_is_scene_render()) {
+      int mb_step = effects->motion_blur_step;
+      DRW_view_viewmat_get(NULL, effects->motion_blur.camera[mb_step].viewmat, false);
+      DRW_view_persmat_get(NULL, effects->motion_blur.camera[mb_step].persmat, false);
+      DRW_view_persmat_get(NULL, effects->motion_blur.camera[mb_step].persinv, true);
+    }
 
-  BKE_camera_params_compute_matrix(&params);
+    if (camera != NULL) {
+      Camera *cam = camera->data;
+      effects->motion_blur_near_far[0] = cam->clip_start;
+      effects->motion_blur_near_far[1] = cam->clip_end;
+    }
+    else {
+      /* Not supported yet. */
+      BLI_assert(0);
+    }
 
-  /* FIXME Should be done per view (MULTIVIEW) */
-  normalize_m4_m4(obmat, cam_cpy.obmat);
-  invert_m4(obmat);
-  mul_m4_m4m4(r_mat, params.winmat, obmat);
+    effects->motion_blur_max = max_ii(0, scene->eevee.motion_blur_max);
+    const float *fs_size = DRW_viewport_size_get();
+    int tx_size[2] = {1 + ((int)fs_size[0] / EEVEE_VELOCITY_TILE_SIZE),
+                      1 + ((int)fs_size[1] / EEVEE_VELOCITY_TILE_SIZE)};
+
+    effects->velocity_tiles_x_tx = DRW_texture_pool_query_2d(
+        tx_size[0], fs_size[1], GPU_RGBA16, &draw_engine_eevee_type);
+    GPU_framebuffer_ensure_config(&fbl->velocity_tiles_fb[0],
+                                  {
+                                      GPU_ATTACHMENT_NONE,
+                                      GPU_ATTACHMENT_TEXTURE(effects->velocity_tiles_x_tx),
+                                  });
+
+    effects->velocity_tiles_tx = DRW_texture_pool_query_2d(
+        tx_size[0], tx_size[1], GPU_RGBA16, &draw_engine_eevee_type);
+    GPU_framebuffer_ensure_config(&fbl->velocity_tiles_fb[1],
+                                  {
+                                      GPU_ATTACHMENT_NONE,
+                                      GPU_ATTACHMENT_TEXTURE(effects->velocity_tiles_tx),
+                                  });
+
+    return EFFECT_MOTION_BLUR | EFFECT_POST_BUFFER | EFFECT_VELOCITY_BUFFER;
+  }
+  return 0;
 }
 
-static void eevee_create_shader_motion_blur(void)
+void EEVEE_motion_blur_step_set(EEVEE_Data *vedata, int step)
 {
-  e_data.motion_blur_sh = DRW_shader_create_fullscreen(datatoc_effect_motion_blur_frag_glsl, NULL);
+  BLI_assert(step < 3);
+  /* Meh, code duplication. Could be avoided if render init would not contain cache init. */
+  if (vedata->stl->effects == NULL) {
+    vedata->stl->effects = MEM_callocN(sizeof(*vedata->stl->effects), __func__);
+  }
+  vedata->stl->effects->motion_blur_step = step;
 }
 
-int EEVEE_motion_blur_init(EEVEE_ViewLayerData *UNUSED(sldata), EEVEE_Data *vedata, Object *camera)
+void EEVEE_motion_blur_cache_init(EEVEE_ViewLayerData *UNUSED(sldata), EEVEE_Data *vedata)
 {
+  EEVEE_PassList *psl = vedata->psl;
   EEVEE_StorageList *stl = vedata->stl;
   EEVEE_EffectsInfo *effects = stl->effects;
-
+  EEVEE_MotionBlurData *mb_data = &effects->motion_blur;
+  DefaultTextureList *dtxl = DRW_viewport_texture_list_get();
   const DRWContextState *draw_ctx = DRW_context_state_get();
-  const Scene *scene_eval = DEG_get_evaluated_scene(draw_ctx->depsgraph);
   Scene *scene = draw_ctx->scene;
 
-  View3D *v3d = draw_ctx->v3d;
-  RegionView3D *rv3d = draw_ctx->rv3d;
-  ARegion *region = draw_ctx->region;
+  if ((effects->enabled_effects & EFFECT_MOTION_BLUR) != 0) {
+    const float *fs_size = DRW_viewport_size_get();
+    int tx_size[2] = {GPU_texture_width(effects->velocity_tiles_tx),
+                      GPU_texture_height(effects->velocity_tiles_tx)};
+    DRWShadingGroup *grp;
+    {
+      DRW_PASS_CREATE(psl->velocity_tiles_x, DRW_STATE_WRITE_COLOR);
+      DRW_PASS_CREATE(psl->velocity_tiles, DRW_STATE_WRITE_COLOR);
+
+      /* Create max velocity tiles in 2 passes. One for X and one for Y */
+      GPUShader *sh = e_data.velocity_tiles_sh;
+      grp = DRW_shgroup_create(sh, psl->velocity_tiles_x);
+      DRW_shgroup_uniform_texture(grp, "velocityBuffer", effects->velocity_tx);
+      DRW_shgroup_uniform_ivec2_copy(grp, "velocityBufferSize", (int[2]){fs_size[0], fs_size[1]});
+      DRW_shgroup_uniform_vec2(grp, "viewportSize", DRW_viewport_size_get(), 1);
+      DRW_shgroup_uniform_vec2(grp, "viewportSizeInv", DRW_viewport_invert_size_get(), 1);
+      DRW_shgroup_uniform_ivec2_copy(grp, "gatherStep", (int[2]){1, 0});
+      DRW_shgroup_call_procedural_triangles(grp, NULL, 1);
+
+      grp = DRW_shgroup_create(sh, psl->velocity_tiles);
+      DRW_shgroup_uniform_texture(grp, "velocityBuffer", effects->velocity_tiles_x_tx);
+      DRW_shgroup_uniform_ivec2_copy(grp, "velocityBufferSize", (int[2]){tx_size[0], fs_size[1]});
+      DRW_shgroup_uniform_ivec2_copy(grp, "gatherStep", (int[2]){0, 1});
+      DRW_shgroup_call_procedural_triangles(grp, NULL, 1);
+
+      /* Expand max tiles by keeping the max tile in each tile neighborhood. */
+      DRW_PASS_CREATE(psl->velocity_tiles_expand[0], DRW_STATE_WRITE_COLOR);
+      DRW_PASS_CREATE(psl->velocity_tiles_expand[1], DRW_STATE_WRITE_COLOR);
+      for (int i = 0; i < 2; i++) {
+        GPUTexture *tile_tx = (i == 0) ? effects->velocity_tiles_tx : effects->velocity_tiles_x_tx;
+        GPUShader *sh_expand = e_data.velocity_tiles_expand_sh;
+        grp = DRW_shgroup_create(sh_expand, psl->velocity_tiles_expand[i]);
+        DRW_shgroup_uniform_ivec2_copy(grp, "velocityBufferSize", tx_size);
+        DRW_shgroup_uniform_texture(grp, "velocityBuffer", tile_tx);
+        DRW_shgroup_uniform_vec2(grp, "viewportSize", DRW_viewport_size_get(), 1);
+        DRW_shgroup_uniform_vec2(grp, "viewportSizeInv", DRW_viewport_invert_size_get(), 1);
+        DRW_shgroup_call_procedural_triangles(grp, NULL, 1);
+      }
+    }
+    {
+      DRW_PASS_CREATE(psl->motion_blur, DRW_STATE_WRITE_COLOR);
+      eGPUSamplerState state = 0;
+      int expand_steps = 1 + (max_ii(0, effects->motion_blur_max - 1) / EEVEE_VELOCITY_TILE_SIZE);
+      GPUTexture *tile_tx = (expand_steps & 1) ? effects->velocity_tiles_x_tx :
+                                                 effects->velocity_tiles_tx;
+
+      grp = DRW_shgroup_create(e_data.motion_blur_sh, psl->motion_blur);
+      DRW_shgroup_uniform_texture(grp, "utilTex", EEVEE_materials_get_util_tex());
+      DRW_shgroup_uniform_texture_ref_ex(grp, "colorBuffer", &effects->source_buffer, state);
+      DRW_shgroup_uniform_texture_ref_ex(grp, "depthBuffer", &dtxl->depth, state);
+      DRW_shgroup_uniform_texture_ref_ex(grp, "velocityBuffer", &effects->velocity_tx, state);
+      DRW_shgroup_uniform_texture(grp, "tileMaxBuffer", tile_tx);
+      DRW_shgroup_uniform_float_copy(grp, "depthScale", scene->eevee.motion_blur_depth_scale);
+      DRW_shgroup_uniform_vec2(grp, "nearFar", effects->motion_blur_near_far, 1);
+      DRW_shgroup_uniform_bool_copy(grp, "isPerspective", DRW_view_is_persp_get(NULL));
+      DRW_shgroup_uniform_vec2(grp, "viewportSize", DRW_viewport_size_get(), 1);
+      DRW_shgroup_uniform_vec2(grp, "viewportSizeInv", DRW_viewport_invert_size_get(), 1);
+      DRW_shgroup_uniform_ivec2_copy(grp, "tileBufferSize", tx_size);
+      DRW_shgroup_call_procedural_triangles(grp, NULL, 1);
+    }
+    {
+      DRW_PASS_CREATE(psl->velocity_object, DRW_STATE_WRITE_COLOR | DRW_STATE_DEPTH_EQUAL);
 
-  if (scene_eval->eevee.flag & SCE_EEVEE_MOTION_BLUR_ENABLED) {
-    /* Update Motion Blur Matrices */
-    if (camera && (camera->type == OB_CAMERA) && (camera->data != NULL)) {
-      float persmat[4][4];
-      float ctime = DEG_get_ctime(draw_ctx->depsgraph);
-      float delta = scene_eval->eevee.motion_blur_shutter;
-      Object *ob_camera_eval = DEG_get_evaluated_object(draw_ctx->depsgraph, camera);
+      grp = DRW_shgroup_create(e_data.motion_blur_object_sh, psl->velocity_object);
+      DRW_shgroup_uniform_mat4(grp, "prevViewProjMatrix", mb_data->camera[MB_PREV].persmat);
+      DRW_shgroup_uniform_mat4(grp, "currViewProjMatrix", mb_data->camera[MB_CURR].persmat);
+      DRW_shgroup_uniform_mat4(grp, "nextViewProjMatrix", mb_data->camera[MB_NEXT].persmat);
+    }
 
-      /* Viewport Matrix */
-      /* Note: This does not have TAA jitter applied. */
-      DRW_view_persmat_get(NULL, persmat, false);
+    EEVEE_motion_blur_data_init(mb_data);
+  }
+  else {
+    psl->motion_blur = NULL;
+    psl->velocity_object = NULL;
+  }
+}
 
-      bool view_is_valid = (stl->g_data->view_updated == false);
+void EEVEE_motion_blur_cache_populate(EEVEE_ViewLayerData *UNUSED(sldata),
+                                      EEVEE_Data *vedata,
+                                      Object *ob)
+{
+  EEVEE_PassList *psl = vedata->psl;
+  EEVEE_StorageList *stl = vedata->stl;
+  EEVEE_EffectsInfo *effects = stl->effects;
+  DRWShadingGroup *grp = NULL;
 
-      if (draw_ctx->evil_C != NULL) {
-        struct wmWindowManager *wm = CTX_wm_manager(draw_ctx->evil_C);
-        view_is_valid = view_is_valid && (ED_screen_animation_no_scrub(wm) == NULL);
-      }
+  if (!DRW_state_is_scene_render() || psl->velocity_object == NULL) {
+    return;
+  }
 
-      /* The view is jittered by the oglrenderer. So avoid testing in this case. */
-      if (!DRW_state_is_image_render()) {
-        view_is_valid = view_is_valid && compare_m4m4(persmat, effects->prev_drw_persmat, FLT_MIN);
-        /* WATCH: assume TAA init code runs last. */
-        if (scene_eval->eevee.taa_samples == 1) {
-          /* Only if TAA is disabled. If not, TAA will update prev_drw_persmat itself. */
-          copy_m4_m4(effects->prev_drw_persmat, persmat);
-        }
-      }
+  const bool is_dupli = (ob->base_flag & BASE_FROM_DUPLI) != 0;
+  /* For now we assume dupli objects are moving. */
+  const bool object_moves = is_dupli || BKE_object_moves_in_time(ob, true);
+  const bool is_deform = BKE_object_is_deform_modified(DRW_context_state_get()->scene, ob);
+
+  if (!(object_moves || is_deform)) {
+    return;
+  }
+
+  EEVEE_ObjectMotionData *mb_data = EEVEE_motion_blur_object_data_get(&effects->motion_blur, ob);
+
+  if (mb_data) {
+    int mb_step = effects->motion_blur_step;
+    /* Store transform  */
+    copy_m4_m4(mb_data->obmat[mb_step], ob->obmat);
 
-      effects->motion_blur_mat_cached = view_is_valid && !DRW_state_is_image_render();
+    EEVEE_GeometryMotionData *mb_geom = EEVEE_motion_blur_geometry_data_get(&effects->motion_blur,
+                                                                            ob);
 
-      /* Current matrix */
-      if (effects->motion_blur_mat_cached == false) {
-        eevee_motion_blur_camera_get_matrix_at_time(
-            scene, region, rv3d, v3d, ob_camera_eval, ctime, effects->current_world_to_ndc);
+    if (mb_step == MB_CURR) {
+      GPUBatch *batch = DRW_cache_object_surface_get(ob);
+      if (batch == NULL) {
+        return;
       }
 
-      /* Only continue if camera is not being keyed */
-      if (DRW_state_is_image_render() ||
-          compare_m4m4(persmat, effects->current_world_to_ndc, 0.0001f)) {
-        /* Past matrix */
-        if (effects->motion_blur_mat_cached == false) {
-          eevee_motion_blur_camera_get_matrix_at_time(
-              scene, region, rv3d, v3d, ob_camera_eval, ctime - delta, effects->past_world_to_ndc);
-
-#if 0 /* for future high quality blur */
-          /* Future matrix */
-          eevee_motion_blur_camera_get_matrix_at_time(
-              scene, region, rv3d, v3d, ob_camera_eval, ctime + delta, effects->future_world_to_ndc);
-#endif
-          invert_m4_m4(effects->current_ndc_to_world, effects->current_world_to_ndc);
-        }
+      /* Fill missing matrices if the object was hidden in previous or next frame. */
+      if (is_zero_m4(mb_data->obmat[MB_PREV])) {
+        copy_m4_m4(mb_data->obmat[MB_PREV], mb_data->obmat[MB_CURR]);
+      }
+      if (is_zero_m4(mb_data->obmat[MB_NEXT])) {
+        copy_m4_m4(mb_data->obmat[MB_NEXT], mb_data->obmat[MB_CURR]);
+      }
 
-        effects->motion_blur_mat_cached = true;
-        effects->motion_blur_samples = scene_eval->eevee.motion_blur_samples;
+      grp = DRW_shgroup_create(e_data.motion_blur_object_sh, psl->velocity_object);
+      DRW_shgroup_uniform_mat4(grp, "prevModelMatrix", mb_data->obmat[MB_PREV]);
+      DRW_shgroup_uniform_mat4(grp, "currModelMatrix", mb_data->obmat[MB_CURR]);
+      DRW_shgroup_uniform_mat4(grp, "nextModelMatrix", mb_data->obmat[MB_NEXT]);
+      DRW_shgroup_uniform_bool(grp, "useDeform", &mb_geom->use_deform, 1);
 
-        if (!e_data.motion_blur_sh) {
-          eevee_create_shader_motion_blur();
-        }
+      DRW_shgroup_call(grp, batch, ob);
 
-        return EFFECT_MOTION_BLUR | EFFECT_POST_BUFFER;
+      if (mb_geom->use_deform) {
+        /* Keep to modify later (after init). */
+        mb_geom->batch = batch;
       }
     }
+    else if (is_deform) {
+      /* Store vertex position buffer. */
+      mb_geom->vbo[mb_step] = DRW_cache_object_pos_vertbuf_get(ob);
+      mb_geom->use_deform = (mb_geom->vbo[mb_step] != NULL);
+    }
+    else {
+      mb_geom->vbo[mb_step] = NULL;
+      mb_geom->use_deform = false;
+    }
   }
-
-  return 0;
 }
 
-void EEVEE_motion_blur_cache_init(EEVEE_ViewLayerData *UNUSED(sldata), EEVEE_Data *vedata)
+void EEVEE_motion_blur_cache_finish(EEVEE_Data *vedata)
 {
-  EEVEE_PassList *psl = vedata->psl;
   EEVEE_StorageList *stl = vedata->stl;
   EEVEE_EffectsInfo *effects = stl->effects;
-  DefaultTextureList *dtxl = DRW_viewport_texture_list_get();
+  GHashIterator ghi;
 
-  struct GPUBatch *quad = DRW_cache_fullscreen_quad_get();
+  if ((effects->enabled_effects & EFFECT_MOTION_BLUR) == 0) {
+    return;
+  }
 
-  if ((effects->enabled_effects & EFFECT_MOTION_BLUR) != 0) {
-    DRW_PASS_CREATE(psl->motion_blur, DRW_STATE_WRITE_COLOR);
-
-    DRWShadingGroup *grp = DRW_shgroup_create(e_data.motion_blur_sh, psl->motion_blur);
-    DRW_shgroup_uniform_int(grp, "samples", &effects->motion_blur_samples, 1);
-    DRW_shgroup_uniform_mat4(grp, "currInvViewProjMatrix", effects->current_ndc_to_world);
-    DRW_shgroup_uniform_mat4(grp, "pastViewProjMatrix", effects->past_world_to_ndc);
-    DRW_shgroup_uniform_texture_ref(grp, "colorBuffer", &effects->source_buffer);
-    DRW_shgroup_uniform_texture_ref(grp, "depthBuffer", &dtxl->depth);
-    DRW_shgroup_call(grp, quad, NULL);
+  for (BLI_ghashIterator_init(&ghi, effects->motion_blur.geom);
+       BLI_ghashIterator_done(&ghi) == false;
+       BLI_ghashIterator_step(&ghi)) {
+    EEVEE_GeometryMotionData *mb_geom = BLI_ghashIterator_getValue(&ghi);
+
+    int mb_step = effects->motion_blur_step;
+
+    if (!mb_geom->use_deform) {
+      continue;
+    }
+
+    if (mb_step == MB_CURR) {
+      /* Modify batch to have data from adjacent frames. */
+      GPUBatch *batch = mb_geom->batch;
+      for (int i = 0; i < MB_CURR; i++) {
+        GPUVertBuf *vbo = mb_geom->vbo[i];
+        if (vbo && batch) {
+          if (vbo->vertex_len != batch->verts[0]->vertex_len) {
+            /* Vertex count mismatch, disable deform motion blur. */
+            mb_geom->use_deform = false;
+            GPU_VERTBUF_DISCARD_SAFE(mb_geom->vbo[MB_PREV]);
+            GPU_VERTBUF_DISCARD_SAFE(mb_geom->vbo[MB_NEXT]);
+            break;
+          }
+          /* Modify the batch to include the previous position. */
+          GPU_batch_vertbuf_add_ex(batch, vbo, true);
+          /* TODO(fclem) keep the vbo around for next (sub)frames. */
+          /* Only do once. */
+          mb_geom->vbo[i] = NULL;
+        }
+      }
+    }
+    else {
+      GPUVertBuf *vbo = mb_geom->vbo[mb_step];
+      /* If this assert fails, it means that different EEVEE_GeometryMotionDatas
+       * has been used for each motion blur step.  */
+      BLI_assert(vbo);
+      if (vbo) {
+        /* Use the vbo to perform the copy on the GPU. */
+        GPU_vertbuf_use(vbo);
+        /* Perform a copy to avoid loosing it after RE_engine_frame_set(). */
+        mb_geom->vbo[mb_step] = vbo = GPU_vertbuf_duplicate(vbo);
+        /* Find and replace "pos" attrib name. */
+        int attrib_id = GPU_vertformat_attr_id_get(&vbo->format, "pos");
+        GPU_vertformat_attr_rename(&vbo->format, attrib_id, (mb_step == MB_PREV) ? "prv" : "nxt");
+      }
+    }
   }
 }
 
@@ -216,6 +381,36 @@ void EEVEE_motion_blur_draw(EEVEE_Data *vedata)
 
   /* Motion Blur */
   if ((effects->enabled_effects & EFFECT_MOTION_BLUR) != 0) {
+    int sample = DRW_state_is_image_render() ? effects->taa_render_sample :
+                                               effects->taa_current_sample;
+    double r;
+    BLI_halton_1d(2, 0.0, sample - 1, &r);
+    effects->motion_blur_sample_offset = r;
+
+    /* Create velocity max tiles in 2 passes. One for each dimension. */
+    GPU_framebuffer_bind(fbl->velocity_tiles_fb[0]);
+    DRW_draw_pass(psl->velocity_tiles_x);
+
+    GPU_framebuffer_bind(fbl->velocity_tiles_fb[1]);
+    DRW_draw_pass(psl->velocity_tiles);
+
+    /* Expand the tiles by reading the neighborhood. Do as many passes as required. */
+    int buf = 0;
+    for (int i = effects->motion_blur_max; i > 0; i -= EEVEE_VELOCITY_TILE_SIZE) {
+      GPU_framebuffer_bind(fbl->velocity_tiles_fb[buf]);
+
+      /* Change viewport to avoid invoking more pixel shaders than necessary since in one of the
+       * buffer the texture is way bigger in height. This avoid creating another texture and
+       * reduce VRAM usage. */
+      int w = GPU_texture_width(effects->velocity_tiles_tx);
+      int h = GPU_texture_height(effects->velocity_tiles_tx);
+      GPU_framebuffer_viewport_set(fbl->velocity_tiles_fb[buf], 0, 0, w, h);
+
+      DRW_draw_pass(psl->velocity_tiles_expand[buf]);
+
+      buf = buf ? 0 : 1;
+    }
+
     GPU_framebuffer_bind(effects->target_buffer);
     DRW_draw_pass(psl->motion_blur);
     SWAP_BUFFERS();
@@ -225,4 +420,7 @@ void EEVEE_motion_blur_draw(EEVEE_Data *vedata)
 void EEVEE_motion_blur_free(void)
 {
   DRW_SHADER_FREE_SAFE(e_data.motion_blur_sh);
+  DRW_SHADER_FREE_SAFE(e_data.motion_blur_object_sh);
+  DRW_SHADER_FREE_SAFE(e_data.velocity_tiles_sh);
+  DRW_SHADER_FREE_SAFE(e_data.velocity_tiles_expand_sh);
 }