Cycles: enable Alembic procedural for final renders

The Alembic procedural was only enabled during viewport renders
originally because it did not have any caching strategy. Now that
is does, we can allow its usage in final renders.

This also removes the `dag_eval_mode` argument passing to
`ModifierTypeInfo.dependsOnTime` which was originally added to detect if
we are doing a viewport render for enabling the procedural.

Differential Revision: https://developer.blender.org/D14520

27 files changed, 34 insertions, 83 deletions

diff --git a/intern/cycles/blender/object.cpp b/intern/cycles/blender/object.cpp
index 3a95746d149..58ea8961845 100644
--- a/intern/cycles/blender/object.cpp
+++ b/intern/cycles/blender/object.cpp
@@ -621,10 +621,8 @@ void BlenderSync::sync_objects(BL::Depsgraph &b_depsgraph,
       bool has_subdivision_modifier = false;
       BL::MeshSequenceCacheModifier b_mesh_cache(PointerRNA_NULL);
 
-      /* Experimental as Blender does not have good support for procedurals at the moment, also
-       * only available in preview renders since currently do not have a good cache policy, the
-       * data being loaded at once for all the frames. */
-      if (experimental && b_v3d) {
+      /* Experimental as Blender does not have good support for procedurals at the moment. */
+      if (experimental) {
         b_mesh_cache = object_mesh_cache_find(b_ob, &has_subdivision_modifier);
         use_procedural = b_mesh_cache && b_mesh_cache.cache_file().use_render_procedural();
       }
diff --git a/source/blender/blenkernel/BKE_cachefile.h b/source/blender/blenkernel/BKE_cachefile.h
index 425207398a0..41a0ad3f763 100644
--- a/source/blender/blenkernel/BKE_cachefile.h
+++ b/source/blender/blenkernel/BKE_cachefile.h
@@ -51,8 +51,7 @@ void BKE_cachefile_reader_free(struct CacheFile *cache_file, struct CacheReader
  * load the data directly if they support it.
  */
 bool BKE_cache_file_uses_render_procedural(const struct CacheFile *cache_file,
-                                           struct Scene *scene,
-                                           int dag_eval_mode);
+                                           struct Scene *scene);
 
 /* Add a layer to the cache_file. Return NULL if the filename is already that of an existing layer
  * or if the number of layers exceeds the maximum allowed layer count. */
diff --git a/source/blender/blenkernel/BKE_modifier.h b/source/blender/blenkernel/BKE_modifier.h
index acdca23b21c..41a02545591 100644
--- a/source/blender/blenkernel/BKE_modifier.h
+++ b/source/blender/blenkernel/BKE_modifier.h
@@ -301,10 +301,8 @@ typedef struct ModifierTypeInfo {
    * changes.
    *
    * This function is optional (assumes false if not present).
-   *
-   * The dag_eval_mode should be of type eEvaluationMode.
    */
-  bool (*dependsOnTime)(struct Scene *scene, struct ModifierData *md, int dag_eval_mode);
+  bool (*dependsOnTime)(struct Scene *scene, struct ModifierData *md);
 
   /**
    * True when a deform modifier uses normals, the requiredDataMask
@@ -421,7 +419,7 @@ void BKE_modifier_copydata(const struct ModifierData *md, struct ModifierData *t
 void BKE_modifier_copydata_ex(const struct ModifierData *md,
                               struct ModifierData *target,
                               int flag);
-bool BKE_modifier_depends_ontime(struct Scene *scene, struct ModifierData *md, int dag_eval_mode);
+bool BKE_modifier_depends_ontime(struct Scene *scene, struct ModifierData *md);
 bool BKE_modifier_supports_mapping(struct ModifierData *md);
 bool BKE_modifier_supports_cage(struct Scene *scene, struct ModifierData *md);
 bool BKE_modifier_couldbe_cage(struct Scene *scene, struct ModifierData *md);
diff --git a/source/blender/blenkernel/BKE_object.h b/source/blender/blenkernel/BKE_object.h
index 4d699e1ff54..e36d71602e3 100644
--- a/source/blender/blenkernel/BKE_object.h
+++ b/source/blender/blenkernel/BKE_object.h
@@ -621,10 +621,7 @@ void BKE_object_groups_clear(struct Main *bmain, struct Scene *scene, struct Obj
  */
 struct KDTree_3d *BKE_object_as_kdtree(struct Object *ob, int *r_tot);
 
-bool BKE_object_modifier_use_time(struct Scene *scene,
-                                  struct Object *ob,
-                                  struct ModifierData *md,
-                                  int dag_eval_mode);
+bool BKE_object_modifier_use_time(struct Scene *scene, struct Object *ob, struct ModifierData *md);
 
 /**
  * \note this function should eventually be replaced by depsgraph functionality.
diff --git a/source/blender/blenkernel/intern/cachefile.c b/source/blender/blenkernel/intern/cachefile.c
index 16fc05266e2..338c74d550c 100644
--- a/source/blender/blenkernel/intern/cachefile.c
+++ b/source/blender/blenkernel/intern/cachefile.c
@@ -417,9 +417,7 @@ float BKE_cachefile_time_offset(const CacheFile *cache_file, const float time, c
   return cache_file->is_sequence ? frame : frame / fps - time_offset;
 }
 
-bool BKE_cache_file_uses_render_procedural(const CacheFile *cache_file,
-                                           Scene *scene,
-                                           const int dag_eval_mode)
+bool BKE_cache_file_uses_render_procedural(const CacheFile *cache_file, Scene *scene)
 {
   RenderEngineType *render_engine_type = RE_engines_find(scene->r.engine);
 
@@ -428,9 +426,7 @@ bool BKE_cache_file_uses_render_procedural(const CacheFile *cache_file,
     return false;
   }
 
-  /* The render time procedural is only enabled during viewport rendering. */
-  const bool is_final_render = (eEvaluationMode)dag_eval_mode == DAG_EVAL_RENDER;
-  return cache_file->use_render_procedural && !is_final_render;
+  return cache_file->use_render_procedural;
 }
 
 CacheFileLayer *BKE_cachefile_add_layer(CacheFile *cache_file, const char filename[1024])
diff --git a/source/blender/blenkernel/intern/constraint.c b/source/blender/blenkernel/intern/constraint.c
index 7a97139748f..fc3f84778f8 100644
--- a/source/blender/blenkernel/intern/constraint.c
+++ b/source/blender/blenkernel/intern/constraint.c
@@ -5412,7 +5412,7 @@ static void transformcache_evaluate(bConstraint *con, bConstraintOb *cob, ListBa
   }
 
   /* Do not process data if using a render time procedural. */
-  if (BKE_cache_file_uses_render_procedural(cache_file, scene, DEG_get_mode(cob->depsgraph))) {
+  if (BKE_cache_file_uses_render_procedural(cache_file, scene)) {
     return;
   }
 
diff --git a/source/blender/blenkernel/intern/modifier.c b/source/blender/blenkernel/intern/modifier.c
index 5af8dfc2b72..395deeda4ad 100644
--- a/source/blender/blenkernel/intern/modifier.c
+++ b/source/blender/blenkernel/intern/modifier.c
@@ -233,11 +233,11 @@ bool BKE_modifier_unique_name(ListBase *modifiers, ModifierData *md)
   return false;
 }
 
-bool BKE_modifier_depends_ontime(Scene *scene, ModifierData *md, const int dag_eval_mode)
+bool BKE_modifier_depends_ontime(Scene *scene, ModifierData *md)
 {
   const ModifierTypeInfo *mti = BKE_modifier_get_info(md->type);
 
-  return mti->dependsOnTime && mti->dependsOnTime(scene, md, dag_eval_mode);
+  return mti->dependsOnTime && mti->dependsOnTime(scene, md);
 }
 
 bool BKE_modifier_supports_mapping(ModifierData *md)
diff --git a/source/blender/blenkernel/intern/object.cc b/source/blender/blenkernel/intern/object.cc
index 833cdb74067..6c232fa8bd9 100644
--- a/source/blender/blenkernel/intern/object.cc
+++ b/source/blender/blenkernel/intern/object.cc
@@ -5236,12 +5236,9 @@ KDTree_3d *BKE_object_as_kdtree(Object *ob, int *r_tot)
 /** \name Object Modifier Utilities
  * \{ */
 
-bool BKE_object_modifier_use_time(Scene *scene,
-                                  Object *ob,
-                                  ModifierData *md,
-                                  const int dag_eval_mode)
+bool BKE_object_modifier_use_time(Scene *scene, Object *ob, ModifierData *md)
 {
-  if (BKE_modifier_depends_ontime(scene, md, dag_eval_mode)) {
+  if (BKE_modifier_depends_ontime(scene, md)) {
     return true;
   }
 
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
index 487f096031e..b5945c06ad3 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
@@ -2088,7 +2088,7 @@ void DepsgraphRelationBuilder::build_object_data_geometry(Object *object)
         ctx.node = reinterpret_cast<::DepsNodeHandle *>(&handle);
         mti->updateDepsgraph(md, &ctx);
       }
-      if (BKE_object_modifier_use_time(scene_, object, md, graph_->mode)) {
+      if (BKE_object_modifier_use_time(scene_, object, md)) {
         TimeSourceKey time_src_key;
         add_relation(time_src_key, obdata_ubereval_key, "Time Source");
       }
diff --git a/source/blender/modifiers/intern/MOD_build.c b/source/blender/modifiers/intern/MOD_build.c
index d7baea7887d..61959d242d8 100644
--- a/source/blender/modifiers/intern/MOD_build.c
+++ b/source/blender/modifiers/intern/MOD_build.c
@@ -46,9 +46,7 @@ static void initData(ModifierData *md)
   MEMCPY_STRUCT_AFTER(bmd, DNA_struct_default_get(BuildModifierData), modifier);
 }
 
-static bool dependsOnTime(struct Scene *UNUSED(scene),
-                          ModifierData *UNUSED(md),
-                          const int UNUSED(dag_eval_mode))
+static bool dependsOnTime(struct Scene *UNUSED(scene), ModifierData *UNUSED(md))
 {
   return true;
 }
diff --git a/source/blender/modifiers/intern/MOD_cloth.c b/source/blender/modifiers/intern/MOD_cloth.c
index 6389f420588..185b05b4cf9 100644
--- a/source/blender/modifiers/intern/MOD_cloth.c
+++ b/source/blender/modifiers/intern/MOD_cloth.c
@@ -201,9 +201,7 @@ static void copyData(const ModifierData *md, ModifierData *target, const int fla
   tclmd->solver_result = NULL;
 }
 
-static bool dependsOnTime(struct Scene *UNUSED(scene),
-                          ModifierData *UNUSED(md),
-                          const int UNUSED(dag_eval_mode))
+static bool dependsOnTime(struct Scene *UNUSED(scene), ModifierData *UNUSED(md))
 {
   return true;
 }
diff --git a/source/blender/modifiers/intern/MOD_collision.c b/source/blender/modifiers/intern/MOD_collision.c
index 9791b046e00..1cb308bb2a0 100644
--- a/source/blender/modifiers/intern/MOD_collision.c
+++ b/source/blender/modifiers/intern/MOD_collision.c
@@ -80,9 +80,7 @@ static void freeData(ModifierData *md)
   }
 }
 
-static bool dependsOnTime(struct Scene *UNUSED(scene),
-                          ModifierData *UNUSED(md),
-                          const int UNUSED(dag_eval_mode))
+static bool dependsOnTime(struct Scene *UNUSED(scene), ModifierData *UNUSED(md))
 {
   return true;
 }
diff --git a/source/blender/modifiers/intern/MOD_displace.c b/source/blender/modifiers/intern/MOD_displace.c
index ca48d4fedd8..7ad7d6eef3d 100644
--- a/source/blender/modifiers/intern/MOD_displace.c
+++ b/source/blender/modifiers/intern/MOD_displace.c
@@ -80,9 +80,7 @@ static void requiredDataMask(Object *UNUSED(ob),
   }
 }
 
-static bool dependsOnTime(struct Scene *UNUSED(scene),
-                          ModifierData *md,
-                          const int UNUSED(dag_eval_mode))
+static bool dependsOnTime(struct Scene *UNUSED(scene), ModifierData *md)
 {
   DisplaceModifierData *dmd = (DisplaceModifierData *)md;
 
diff --git a/source/blender/modifiers/intern/MOD_dynamicpaint.c b/source/blender/modifiers/intern/MOD_dynamicpaint.c
index 64f603b99a9..f8cf80b673c 100644
--- a/source/blender/modifiers/intern/MOD_dynamicpaint.c
+++ b/source/blender/modifiers/intern/MOD_dynamicpaint.c
@@ -142,9 +142,7 @@ static void updateDepsgraph(ModifierData *md, const ModifierUpdateDepsgraphConte
   }
 }
 
-static bool dependsOnTime(struct Scene *UNUSED(scene),
-                          ModifierData *UNUSED(md),
-                          const int UNUSED(dag_eval_mode))
+static bool dependsOnTime(struct Scene *UNUSED(scene), ModifierData *UNUSED(md))
 {
   return true;
 }
diff --git a/source/blender/modifiers/intern/MOD_explode.c b/source/blender/modifiers/intern/MOD_explode.c
index b3bcd181de9..87ff648f13d 100644
--- a/source/blender/modifiers/intern/MOD_explode.c
+++ b/source/blender/modifiers/intern/MOD_explode.c
@@ -71,9 +71,7 @@ static void copyData(const ModifierData *md, ModifierData *target, const int fla
 
   temd->facepa = NULL;
 }
-static bool dependsOnTime(struct Scene *UNUSED(scene),
-                          ModifierData *UNUSED(md),
-                          const int UNUSED(dag_eval_mode))
+static bool dependsOnTime(struct Scene *UNUSED(scene), ModifierData *UNUSED(md))
 {
   return true;
 }
diff --git a/source/blender/modifiers/intern/MOD_fluid.c b/source/blender/modifiers/intern/MOD_fluid.c
index a4c34df7ccf..562f0df510d 100644
--- a/source/blender/modifiers/intern/MOD_fluid.c
+++ b/source/blender/modifiers/intern/MOD_fluid.c
@@ -151,9 +151,7 @@ static Mesh *modifyMesh(ModifierData *md, const ModifierEvalContext *ctx, Mesh *
 #endif /* WITH_FLUID */
 }
 
-static bool dependsOnTime(struct Scene *UNUSED(scene),
-                          ModifierData *UNUSED(md),
-                          const int UNUSED(dag_eval_mode))
+static bool dependsOnTime(struct Scene *UNUSED(scene), ModifierData *UNUSED(md))
 {
   return true;
 }
diff --git a/source/blender/modifiers/intern/MOD_meshcache.c b/source/blender/modifiers/intern/MOD_meshcache.c
index e5a62ba96b6..6f065797b43 100644
--- a/source/blender/modifiers/intern/MOD_meshcache.c
+++ b/source/blender/modifiers/intern/MOD_meshcache.c
@@ -54,9 +54,7 @@ static void initData(ModifierData *md)
   MEMCPY_STRUCT_AFTER(mcmd, DNA_struct_default_get(MeshCacheModifierData), modifier);
 }
 
-static bool dependsOnTime(struct Scene *UNUSED(scene),
-                          ModifierData *md,
-                          const int UNUSED(dag_eval_mode))
+static bool dependsOnTime(struct Scene *UNUSED(scene), ModifierData *md)
 {
   MeshCacheModifierData *mcmd = (MeshCacheModifierData *)md;
   return (mcmd->play_mode == MOD_MESHCACHE_PLAY_CFEA);
diff --git a/source/blender/modifiers/intern/MOD_meshsequencecache.cc b/source/blender/modifiers/intern/MOD_meshsequencecache.cc
index cfc5b17f37e..dabbcbaf818 100644
--- a/source/blender/modifiers/intern/MOD_meshsequencecache.cc
+++ b/source/blender/modifiers/intern/MOD_meshsequencecache.cc
@@ -169,7 +169,7 @@ static Mesh *modifyMesh(ModifierData *md, const ModifierEvalContext *ctx, Mesh *
 
   /* Do not process data if using a render procedural, return a box instead for displaying in the
    * viewport. */
-  if (BKE_cache_file_uses_render_procedural(cache_file, scene, DEG_get_mode(ctx->depsgraph))) {
+  if (BKE_cache_file_uses_render_procedural(cache_file, scene)) {
     return generate_bounding_box_mesh(ctx->object, org_mesh);
   }
 
@@ -263,13 +263,13 @@ static Mesh *modifyMesh(ModifierData *md, const ModifierEvalContext *ctx, Mesh *
 #endif
 }
 
-static bool dependsOnTime(Scene *scene, ModifierData *md, const int dag_eval_mode)
+static bool dependsOnTime(Scene *scene, ModifierData *md)
 {
 #if defined(WITH_USD) || defined(WITH_ALEMBIC)
   MeshSeqCacheModifierData *mcmd = reinterpret_cast<MeshSeqCacheModifierData *>(md);
   /* Do not evaluate animations if using the render engine procedural. */
   return (mcmd->cache_file != nullptr) &&
-         !BKE_cache_file_uses_render_procedural(mcmd->cache_file, scene, dag_eval_mode);
+         !BKE_cache_file_uses_render_procedural(mcmd->cache_file, scene);
 #else
   UNUSED_VARS(scene, md, dag_eval_mode);
   return false;
diff --git a/source/blender/modifiers/intern/MOD_nodes.cc b/source/blender/modifiers/intern/MOD_nodes.cc
index 89d7868831d..7545bae43b3 100644
--- a/source/blender/modifiers/intern/MOD_nodes.cc
+++ b/source/blender/modifiers/intern/MOD_nodes.cc
@@ -316,9 +316,7 @@ static bool check_tree_for_time_node(const bNodeTree &tree,
   return false;
 }
 
-static bool dependsOnTime(struct Scene *UNUSED(scene),
-                          ModifierData *md,
-                          const int UNUSED(dag_eval_mode))
+static bool dependsOnTime(struct Scene *UNUSED(scene), ModifierData *md)
 {
   const NodesModifierData *nmd = reinterpret_cast<NodesModifierData *>(md);
   const bNodeTree *tree = nmd->node_group;
diff --git a/source/blender/modifiers/intern/MOD_softbody.c b/source/blender/modifiers/intern/MOD_softbody.c
index d43e26f25e1..d8379cc870a 100644
--- a/source/blender/modifiers/intern/MOD_softbody.c
+++ b/source/blender/modifiers/intern/MOD_softbody.c
@@ -47,9 +47,7 @@ static void deformVerts(ModifierData *UNUSED(md),
       ctx->depsgraph, scene, ctx->object, DEG_get_ctime(ctx->depsgraph), vertexCos, verts_num);
 }
 
-static bool dependsOnTime(struct Scene *UNUSED(scene),
-                          ModifierData *UNUSED(md),
-                          const int UNUSED(dag_eval_mode))
+static bool dependsOnTime(struct Scene *UNUSED(scene), ModifierData *UNUSED(md))
 {
   return true;
 }
diff --git a/source/blender/modifiers/intern/MOD_surface.c b/source/blender/modifiers/intern/MOD_surface.c
index f3811d98cd1..3e75e325e44 100644
--- a/source/blender/modifiers/intern/MOD_surface.c
+++ b/source/blender/modifiers/intern/MOD_surface.c
@@ -83,9 +83,7 @@ static void freeData(ModifierData *md)
   }
 }
 
-static bool dependsOnTime(struct Scene *UNUSED(scene),
-                          ModifierData *UNUSED(md),
-                          const int UNUSED(dag_eval_mode))
+static bool dependsOnTime(struct Scene *UNUSED(scene), ModifierData *UNUSED(md))
 {
   return true;
 }
diff --git a/source/blender/modifiers/intern/MOD_volume_displace.cc b/source/blender/modifiers/intern/MOD_volume_displace.cc
index c4a822125ba..059cfdbdd4e 100644
--- a/source/blender/modifiers/intern/MOD_volume_displace.cc
+++ b/source/blender/modifiers/intern/MOD_volume_displace.cc
@@ -82,9 +82,7 @@ static void foreachTexLink(ModifierData *md, Object *ob, TexWalkFunc walk, void
   walk(userData, ob, md, "texture");
 }
 
-static bool dependsOnTime(struct Scene *UNUSED(scene),
-                          ModifierData *md,
-                          const int UNUSED(dag_eval_mode))
+static bool dependsOnTime(struct Scene *UNUSED(scene), ModifierData *md)
 {
   VolumeDisplaceModifierData *vdmd = reinterpret_cast<VolumeDisplaceModifierData *>(md);
   if (vdmd->texture) {
diff --git a/source/blender/modifiers/intern/MOD_warp.c b/source/blender/modifiers/intern/MOD_warp.c
index 8042172f204..e95d2983639 100644
--- a/source/blender/modifiers/intern/MOD_warp.c
+++ b/source/blender/modifiers/intern/MOD_warp.c
@@ -103,9 +103,7 @@ static void matrix_from_obj_pchan(float mat[4][4],
   }
 }
 
-static bool dependsOnTime(struct Scene *UNUSED(scene),
-                          ModifierData *md,
-                          const int UNUSED(dag_eval_mode))
+static bool dependsOnTime(struct Scene *UNUSED(scene), ModifierData *md)
 {
   WarpModifierData *wmd = (WarpModifierData *)md;
 
diff --git a/source/blender/modifiers/intern/MOD_wave.c b/source/blender/modifiers/intern/MOD_wave.c
index 4da2d67b8a6..73b26dc29cd 100644
--- a/source/blender/modifiers/intern/MOD_wave.c
+++ b/source/blender/modifiers/intern/MOD_wave.c
@@ -55,9 +55,7 @@ static void initData(ModifierData *md)
   MEMCPY_STRUCT_AFTER(wmd, DNA_struct_default_get(WaveModifierData), modifier);
 }
 
-static bool dependsOnTime(struct Scene *UNUSED(scene),
-                          ModifierData *UNUSED(md),
-                          const int UNUSED(dag_eval_mode))
+static bool dependsOnTime(struct Scene *UNUSED(scene), ModifierData *UNUSED(md))
 {
   return true;
 }
diff --git a/source/blender/modifiers/intern/MOD_weightvgedit.c b/source/blender/modifiers/intern/MOD_weightvgedit.c
index 02991558c18..2c733542e51 100644
--- a/source/blender/modifiers/intern/MOD_weightvgedit.c
+++ b/source/blender/modifiers/intern/MOD_weightvgedit.c
@@ -97,9 +97,7 @@ static void requiredDataMask(Object *UNUSED(ob),
   /* No need to ask for CD_PREVIEW_MLOOPCOL... */
 }
 
-static bool dependsOnTime(struct Scene *UNUSED(scene),
-                          ModifierData *md,
-                          const int UNUSED(dag_eval_mode))
+static bool dependsOnTime(struct Scene *UNUSED(scene), ModifierData *md)
 {
   WeightVGEditModifierData *wmd = (WeightVGEditModifierData *)md;
 
diff --git a/source/blender/modifiers/intern/MOD_weightvgmix.c b/source/blender/modifiers/intern/MOD_weightvgmix.c
index 52c5e96c68e..b827d41e80a 100644
--- a/source/blender/modifiers/intern/MOD_weightvgmix.c
+++ b/source/blender/modifiers/intern/MOD_weightvgmix.c
@@ -145,9 +145,7 @@ static void requiredDataMask(Object *UNUSED(ob),
   /* No need to ask for CD_PREVIEW_MLOOPCOL... */
 }
 
-static bool dependsOnTime(struct Scene *UNUSED(scene),
-                          ModifierData *md,
-                          const int UNUSED(dag_eval_mode))
+static bool dependsOnTime(struct Scene *UNUSED(scene), ModifierData *md)
 {
   WeightVGMixModifierData *wmd = (WeightVGMixModifierData *)md;
 
diff --git a/source/blender/modifiers/intern/MOD_weightvgproximity.c b/source/blender/modifiers/intern/MOD_weightvgproximity.c
index 7f11d348eff..43a90b2a4ac 100644
--- a/source/blender/modifiers/intern/MOD_weightvgproximity.c
+++ b/source/blender/modifiers/intern/MOD_weightvgproximity.c
@@ -347,9 +347,7 @@ static void requiredDataMask(Object *UNUSED(ob),
   /* No need to ask for CD_PREVIEW_MLOOPCOL... */
 }
 
-static bool dependsOnTime(struct Scene *UNUSED(scene),
-                          ModifierData *md,
-                          const int UNUSED(dag_eval_mode))
+static bool dependsOnTime(struct Scene *UNUSED(scene), ModifierData *md)
 {
   WeightVGProximityModifierData *wmd = (WeightVGProximityModifierData *)md;