Fix T77409: Crash showing vertex/face duplicators in edit-mode

Support duplicators in edit-mode without creating a mesh copy.

1 files changed, 371 insertions, 157 deletions

diff --git a/source/blender/blenkernel/intern/object_dupli.c b/source/blender/blenkernel/intern/object_dupli.c
index 452c1657ed5..2c71ef3f471 100644
--- a/source/blender/blenkernel/intern/object_dupli.c
+++ b/source/blender/blenkernel/intern/object_dupli.c
@@ -30,6 +30,7 @@
 #include "BLI_listbase.h"
 #include "BLI_string_utf8.h"
 
+#include "BLI_alloca.h"
 #include "BLI_math.h"
 #include "BLI_rand.h"
 
@@ -43,6 +44,7 @@
 #include "BKE_collection.h"
 #include "BKE_duplilist.h"
 #include "BKE_editmesh.h"
+#include "BKE_editmesh_cache.h"
 #include "BKE_font.h"
 #include "BKE_global.h"
 #include "BKE_idprop.h"
@@ -300,6 +302,55 @@ static void make_child_duplis(const DupliContext *ctx,
 /** \} */
 
 /* -------------------------------------------------------------------- */
+/** \name Internal Data Access Utilities
+ * \{ */
+
+static Mesh *mesh_data_from_duplicator_object(Object *ob,
+                                              BMEditMesh **r_em,
+                                              const float (**r_vert_coords)[3],
+                                              const float (**r_vert_normals)[3])
+{
+  /* Gather mesh info. */
+  BMEditMesh *em = BKE_editmesh_from_object(ob);
+  Mesh *me_eval;
+
+  *r_em = NULL;
+  *r_vert_coords = NULL;
+  if (r_vert_normals != NULL) {
+    *r_vert_normals = NULL;
+  }
+
+  /* We do not need any render-specific handling anymore, depsgraph takes care of that. */
+  /* NOTE: Do direct access to the evaluated mesh: this function is used
+   * during meta balls evaluation. But even without those all the objects
+   * which are needed for correct instancing are already evaluated. */
+  if (em != NULL) {
+    /* Note that this will only show deformation if #eModifierMode_OnCage is enabled.
+     * We could change this but it matches 2.7x behavior. */
+    me_eval = em->mesh_eval_cage;
+    if ((me_eval == NULL) || (me_eval->runtime.wrapper_type == ME_WRAPPER_TYPE_BMESH)) {
+      *r_em = em;
+      if (me_eval != NULL) {
+        EditMeshData *emd = me_eval->runtime.edit_data;
+        if ((emd != NULL) && (emd->vertexCos != NULL)) {
+          *r_vert_coords = emd->vertexCos;
+          if (r_vert_normals != NULL) {
+            BKE_editmesh_cache_ensure_vert_normals(em, emd);
+            *r_vert_normals = emd->vertexNos;
+          }
+        }
+      }
+    }
+  }
+  else {
+    me_eval = BKE_object_get_evaluated_mesh(ob);
+  }
+  return me_eval;
+}
+
+/** \} */
+
+/* -------------------------------------------------------------------- */
 /** \name Dupli-Collection Implementation (#OB_DUPLICOLLECTION)
  * \{ */
 
@@ -348,124 +399,178 @@ static const DupliGenerator gen_dupli_collection = {
 /** \name Dupli-Vertices Implementation (#OB_DUPLIVERTS for Geometry)
  * \{ */
 
-typedef struct VertexDupliData {
+typedef struct VertexDupliData_Mesh {
   Mesh *me_eval;
-  BMEditMesh *edit_mesh;
+
   int totvert;
+  MVert *mvert;
+
   float (*orco)[3];
+
   bool use_rotation;
+} VertexDupliData_Mesh;
 
-  const DupliContext *ctx;
-  Object *inst_ob; /* object to instantiate (argument for vertex map callback) */
-  float child_imat[4][4];
-} VertexDupliData;
+typedef struct VertexDupliData_BMesh {
+  BMEditMesh *em;
+
+  /* Can be NULL. */
+  const float (*vert_coords)[3];
+  const float (*vert_normals)[3];
+
+  bool has_orco;
+  bool use_rotation;
+} VertexDupliData_BMesh;
 
 static void get_duplivert_transform(const float co[3],
-                                    const short no[3],
-                                    bool use_rotation,
+                                    const float no[3],
+                                    const bool use_rotation,
                                     short axis,
                                     short upflag,
-                                    float mat[4][4])
+                                    float r_mat[4][4])
 {
   float quat[4];
   const float size[3] = {1.0f, 1.0f, 1.0f};
 
   if (use_rotation) {
-    /* construct rotation matrix from normals */
-    float nor_f[3];
-    nor_f[0] = (float)-no[0];
-    nor_f[1] = (float)-no[1];
-    nor_f[2] = (float)-no[2];
-    vec_to_quat(quat, nor_f, axis, upflag);
+    /* Construct rotation matrix from normals. */
+    float no_flip[3];
+    negate_v3_v3(no_flip, no);
+    vec_to_quat(quat, no_flip, axis, upflag);
   }
   else {
     unit_qt(quat);
   }
 
-  loc_quat_size_to_mat4(mat, co, quat, size);
+  loc_quat_size_to_mat4(r_mat, co, quat, size);
 }
 
-static void vertex_dupli(const VertexDupliData *vdd,
-                         int index,
-                         const float co[3],
-                         const short no[3])
+/**
+ * \param no: The direction, doesn't need to be normalized.
+ */
+static DupliObject *vertex_dupli(const DupliContext *ctx,
+                                 Object *child,
+                                 const float child_imat[4][4],
+                                 int index,
+                                 float space_mat[4][4])
 {
-  Object *inst_ob = vdd->inst_ob;
-  DupliObject *dob;
-  float obmat[4][4], space_mat[4][4];
+  float obmat[4][4];
 
-  /* obmat is transform to vertex */
-  get_duplivert_transform(co, no, vdd->use_rotation, inst_ob->trackflag, inst_ob->upflag, obmat);
-  /* make offset relative to inst_ob using relative child transform */
-  mul_mat3_m4_v3((float(*)[4])vdd->child_imat, obmat[3]);
-  /* apply obmat _after_ the local vertex transform */
-  mul_m4_m4m4(obmat, inst_ob->obmat, obmat);
+  /* Make offset relative to child using relative child transform. */
+  mul_mat3_m4_v3(child_imat, space_mat[3]);
 
-  /* space matrix is constructed by removing obmat transform,
-   * this yields the worldspace transform for recursive duplis
-   */
-  mul_m4_m4m4(space_mat, obmat, inst_ob->imat);
+  /* Apply `obmat` _after_ the local vertex transform. */
+  mul_m4_m4m4(obmat, child->obmat, space_mat);
 
-  dob = make_dupli(vdd->ctx, vdd->inst_ob, obmat, index);
+  DupliObject *dob = make_dupli(ctx, child, obmat, index);
 
-  if (vdd->orco) {
-    copy_v3_v3(dob->orco, vdd->orco[index]);
-  }
+  /* Recursion. */
+  make_recursive_duplis(ctx, child, space_mat, index);
 
-  /* recursion */
-  make_recursive_duplis(vdd->ctx, vdd->inst_ob, space_mat, index);
+  return dob;
 }
 
-static void make_child_duplis_verts(const DupliContext *ctx, void *userdata, Object *child)
+static void make_child_duplis_verts_from_mesh(const DupliContext *ctx,
+                                              void *userdata,
+                                              Object *child)
 {
-  VertexDupliData *vdd = userdata;
-  Mesh *me_eval = vdd->me_eval;
+  VertexDupliData_Mesh *vdd = userdata;
 
-  vdd->inst_ob = child;
-  invert_m4_m4(child->imat, child->obmat);
-  /* relative transform from parent to child space */
-  mul_m4_m4m4(vdd->child_imat, child->imat, ctx->object->obmat);
+  const MVert *mvert = vdd->mvert;
+  const int totvert = vdd->totvert;
 
-  const MVert *mvert = me_eval->mvert;
-  for (int i = 0; i < me_eval->totvert; i++) {
-    vertex_dupli(vdd, i, mvert[i].co, mvert[i].no);
+  invert_m4_m4(child->imat, child->obmat);
+  /* Relative transform from parent to child space. */
+  float child_imat[4][4];
+  mul_m4_m4m4(child_imat, child->imat, ctx->object->obmat);
+
+  const MVert *mv = mvert;
+  for (int i = 0; i < totvert; i++, mv++) {
+    const float no[3] = {mv->no[0], mv->no[1], mv->no[2]};
+    /* space_mat is transform to vertex. */
+    float space_mat[4][4];
+    get_duplivert_transform(
+        mv->co, no, vdd->use_rotation, child->trackflag, child->upflag, space_mat);
+    DupliObject *dob = vertex_dupli(ctx, child, child_imat, i, space_mat);
+    if (vdd->orco) {
+      copy_v3_v3(dob->orco, vdd->orco[i]);
+    }
   }
 }
 
-static void make_duplis_verts(const DupliContext *ctx)
+static void make_child_duplis_verts_from_bmesh(const DupliContext *ctx,
+                                               void *userdata,
+                                               Object *child)
 {
-  Object *parent = ctx->object;
-  VertexDupliData vdd;
+  VertexDupliData_BMesh *vdd = userdata;
+  BMEditMesh *em = vdd->em;
 
-  vdd.ctx = ctx;
-  vdd.use_rotation = parent->transflag & OB_DUPLIROT;
+  invert_m4_m4(child->imat, child->obmat);
+  /* Relative transform from parent to child space. */
+  float child_imat[4][4];
+  mul_m4_m4m4(child_imat, child->imat, ctx->object->obmat);
 
-  /* gather mesh info */
-  {
-    vdd.edit_mesh = BKE_editmesh_from_object(parent);
-
-    /* We do not need any render-specific handling anymore, depsgraph takes care of that. */
-    /* NOTE: Do direct access to the evaluated mesh: this function is used
-     * during meta balls evaluation. But even without those all the objects
-     * which are needed for correct instancing are already evaluated. */
-    if (vdd.edit_mesh != NULL) {
-      vdd.me_eval = vdd.edit_mesh->mesh_eval_cage;
+  BMVert *v;
+  BMIter iter;
+  int i;
+
+  const float(*vert_coords)[3] = vdd->vert_coords;
+  const float(*vert_normals)[3] = vdd->vert_normals;
+
+  BM_ITER_MESH_INDEX (v, &iter, em->bm, BM_VERTS_OF_MESH, i) {
+    const float *co, *no;
+    if (vert_coords != NULL) {
+      co = vert_coords[i];
+      no = vert_normals[i];
     }
     else {
-      vdd.me_eval = BKE_object_get_evaluated_mesh(parent);
+      co = v->co;
+      no = v->no;
     }
 
-    if (vdd.me_eval == NULL) {
-      return;
+    /* space_mat is transform to vertex. */
+    float space_mat[4][4];
+    get_duplivert_transform(co, no, vdd->use_rotation, child->trackflag, child->upflag, space_mat);
+    DupliObject *dob = vertex_dupli(ctx, child, child_imat, i, space_mat);
+    if (vdd->has_orco) {
+      copy_v3_v3(dob->orco, v->co);
     }
-
-    vdd.orco = CustomData_get_layer(&vdd.me_eval->vdata, CD_ORCO);
-    vdd.totvert = vdd.me_eval->totvert;
   }
+}
+
+static void make_duplis_verts(const DupliContext *ctx)
+{
+  Object *parent = ctx->object;
+
+  const bool use_rotation = parent->transflag & OB_DUPLIROT;
 
-  make_child_duplis(ctx, &vdd, make_child_duplis_verts);
+  /* Gather mesh info. */
+  BMEditMesh *em = NULL;
+  const float(*vert_coords)[3] = NULL;
+  const float(*vert_normals)[3] = NULL;
+  Mesh *me_eval = mesh_data_from_duplicator_object(parent, &em, &vert_coords, &vert_normals);
+  if (em == NULL && me_eval == NULL) {
+    return;
+  }
 
-  vdd.me_eval = NULL;
+  if (em != NULL) {
+    VertexDupliData_BMesh vdd = {
+        .em = em,
+        .vert_coords = vert_coords,
+        .vert_normals = vert_normals,
+        .has_orco = (vert_coords != NULL),
+        .use_rotation = use_rotation,
+    };
+    make_child_duplis(ctx, &vdd, make_child_duplis_verts_from_bmesh);
+  }
+  else {
+    VertexDupliData_Mesh vdd = {
+        .use_rotation = use_rotation,
+    };
+    vdd.orco = CustomData_get_layer(&me_eval->vdata, CD_ORCO);
+    vdd.totvert = me_eval->totvert;
+    vdd.mvert = me_eval->mvert;
+    make_child_duplis(ctx, &vdd, make_child_duplis_verts_from_mesh);
+  }
 }
 
 static const DupliGenerator gen_dupli_verts = {
@@ -611,37 +716,55 @@ static const DupliGenerator gen_dupli_verts_font = {
 /** \name Dupli-Faces Implementation (#OB_DUPLIFACES)
  * \{ */
 
-typedef struct FaceDupliData {
+typedef struct FaceDupliData_Mesh {
   Mesh *me_eval;
+
   int totface;
   MPoly *mpoly;
   MLoop *mloop;
   MVert *mvert;
+
   float (*orco)[3];
   MLoopUV *mloopuv;
   bool use_scale;
-} FaceDupliData;
+} FaceDupliData_Mesh;
 
-static void get_dupliface_transform(
-    MPoly *mpoly, MLoop *mloop, MVert *mvert, bool use_scale, float scale_fac, float mat[4][4])
+typedef struct FaceDupliData_BMesh {
+  BMEditMesh *em;
+
+  bool has_orco, has_uvs;
+  int cd_loop_uv_offset;
+  /* Can be NULL. */
+  const float (*vert_coords)[3];
+  bool use_scale;
+} FaceDupliData_BMesh;
+
+static void get_dupliface_transform_from_coords(const float coords[][3],
+                                                const int coords_len,
+                                                const bool use_scale,
+                                                const float scale_fac,
+                                                float r_mat[4][4])
 {
   float loc[3], quat[4], scale, size[3];
-  float f_no[3];
 
   /* location */
-  BKE_mesh_calc_poly_center(mpoly, mloop, mvert, loc);
+  {
+    const float w = 1.0f / (float)coords_len;
+    zero_v3(loc);
+    for (int i = 0; i < coords_len; i++) {
+      madd_v3_v3fl(loc, coords[i], w);
+    }
+  }
   /* rotation */
   {
-    const float *v1, *v2, *v3;
-    BKE_mesh_calc_poly_normal(mpoly, mloop, mvert, f_no);
-    v1 = mvert[mloop[0].v].co;
-    v2 = mvert[mloop[1].v].co;
-    v3 = mvert[mloop[2].v].co;
-    tri_to_quat_ex(quat, v1, v2, v3, f_no);
+    float f_no[3];
+    cross_poly_v3(f_no, coords, (uint)coords_len);
+    normalize_v3(f_no);
+    tri_to_quat_ex(quat, coords[0], coords[1], coords[2], f_no);
   }
   /* scale */
   if (use_scale) {
-    float area = BKE_mesh_calc_poly_area(mpoly, mloop, mvert);
+    const float area = area_poly_v3(coords, (uint)coords_len);
     scale = sqrtf(area) * scale_fac;
   }
   else {
@@ -649,58 +772,108 @@ static void get_dupliface_transform(
   }
   size[0] = size[1] = size[2] = scale;
 
-  loc_quat_size_to_mat4(mat, loc, quat, size);
+  loc_quat_size_to_mat4(r_mat, loc, quat, size);
 }
 
-static void make_child_duplis_faces(const DupliContext *ctx, void *userdata, Object *inst_ob)
+static void get_dupliface_transform_from_mesh(const MPoly *mpoly,
+                                              const MLoop *mloopstart,
+                                              const MVert *mvert,
+                                              const bool use_scale,
+                                              const float scale_fac,
+                                              float r_mat[4][4])
 {
-  FaceDupliData *fdd = userdata;
-  MPoly *mpoly = fdd->mpoly, *mp;
-  MLoop *mloop = fdd->mloop;
-  MVert *mvert = fdd->mvert;
-  float(*orco)[3] = fdd->orco;
-  MLoopUV *mloopuv = fdd->mloopuv;
-  int a, totface = fdd->totface;
-  float child_imat[4][4];
-  DupliObject *dob;
+  const MLoop *l_iter = mloopstart;
+  float(*coords)[3] = BLI_array_alloca(coords, (size_t)mpoly->totloop);
+  for (int i = 0; i < mpoly->totloop; i++, l_iter++) {
+    copy_v3_v3(coords[i], mvert[l_iter->v].co);
+  }
+  get_dupliface_transform_from_coords(coords, mpoly->totloop, use_scale, scale_fac, r_mat);
+}
 
-  invert_m4_m4(inst_ob->imat, inst_ob->obmat);
-  /* relative transform from parent to child space */
-  mul_m4_m4m4(child_imat, inst_ob->imat, ctx->object->obmat);
+static void get_dupliface_transform_from_bmesh(BMFace *f,
+                                               const float (*vert_coords)[3],
+                                               const bool use_scale,
+                                               const float scale_fac,
+                                               float r_mat[4][4])
+{
+  BMLoop *l_first, *l_iter;
+  float(*coords)[3] = BLI_array_alloca(coords, (size_t)f->len);
+  int i = 0;
+  l_iter = l_first = BM_FACE_FIRST_LOOP(f);
+  if (vert_coords != NULL) {
+    do {
+      copy_v3_v3(coords[i], vert_coords[BM_elem_index_get(l_iter->v)]);
+    } while ((void)(i++), (l_iter = l_iter->next) != l_first);
+  }
+  else {
+    do {
+      copy_v3_v3(coords[i], l_iter->v->co);
+    } while ((void)(i++), (l_iter = l_iter->next) != l_first);
+  }
+  get_dupliface_transform_from_coords(coords, f->len, use_scale, scale_fac, r_mat);
+}
 
-  for (a = 0, mp = mpoly; a < totface; a++, mp++) {
-    MLoop *loopstart = mloop + mp->loopstart;
-    float space_mat[4][4], obmat[4][4];
+static DupliObject *face_dupli(const DupliContext *ctx,
+                               Object *child,
+                               const float child_imat[4][4],
+                               const int index,
+                               float obmat[4][4])
+{
+  float space_mat[4][4];
 
-    if (UNLIKELY(mp->totloop < 3)) {
-      continue;
-    }
+  /* Make offset relative to child using relative child transform. */
+  mul_mat3_m4_v3(child_imat, obmat[3]);
 
-    /* obmat is transform to face */
-    get_dupliface_transform(
-        mp, loopstart, mvert, fdd->use_scale, ctx->object->instance_faces_scale, obmat);
-    /* make offset relative to inst_ob using relative child transform */
-    mul_mat3_m4_v3(child_imat, obmat[3]);
-
-    /* XXX ugly hack to ensure same behavior as in master
-     * this should not be needed, parentinv is not consistent
-     * outside of parenting.
-     */
-    {
-      float imat[3][3];
-      copy_m3_m4(imat, inst_ob->parentinv);
-      mul_m4_m3m4(obmat, imat, obmat);
-    }
+  /* XXX ugly hack to ensure same behavior as in master this should not be needed,
+   * #Object.parentinv is not consistent outside of parenting. */
+  {
+    float imat[3][3];
+    copy_m3_m4(imat, child->parentinv);
+    mul_m4_m3m4(obmat, imat, obmat);
+  }
 
-    /* apply obmat _after_ the local face transform */
-    mul_m4_m4m4(obmat, inst_ob->obmat, obmat);
+  /* Apply `obmat` _after_ the local face transform. */
+  mul_m4_m4m4(obmat, child->obmat, obmat);
 
-    /* space matrix is constructed by removing obmat transform,
-     * this yields the worldspace transform for recursive duplis
-     */
-    mul_m4_m4m4(space_mat, obmat, inst_ob->imat);
+  /* Space matrix is constructed by removing \a obmat transform,
+   * this yields the world-space transform for recursive duplis. */
+  mul_m4_m4m4(space_mat, obmat, child->imat);
 
-    dob = make_dupli(ctx, inst_ob, obmat, a);
+  DupliObject *dob = make_dupli(ctx, child, obmat, index);
+
+  /* Recursion. */
+  make_recursive_duplis(ctx, child, space_mat, index);
+
+  return dob;
+}
+
+static void make_child_duplis_faces_from_mesh(const DupliContext *ctx,
+                                              void *userdata,
+                                              Object *child)
+{
+  FaceDupliData_Mesh *fdd = userdata;
+  const MPoly *mpoly = fdd->mpoly, *mp;
+  const MLoop *mloop = fdd->mloop;
+  const MVert *mvert = fdd->mvert;
+  const float(*orco)[3] = fdd->orco;
+  const MLoopUV *mloopuv = fdd->mloopuv;
+  const int totface = fdd->totface;
+  int a;
+
+  float child_imat[4][4];
+
+  invert_m4_m4(child->imat, child->obmat);
+  /* Relative transform from parent to child space. */
+  mul_m4_m4m4(child_imat, child->imat, ctx->object->obmat);
+  const float scale_fac = ctx->object->instance_faces_scale;
+
+  for (a = 0, mp = mpoly; a < totface; a++, mp++) {
+    const MLoop *loopstart = mloop + mp->loopstart;
+    float obmat[4][4];
+
+    /* `obmat` is transform to face. */
+    get_dupliface_transform_from_mesh(mp, loopstart, mvert, fdd->use_scale, scale_fac, obmat);
+    DupliObject *dob = face_dupli(ctx, child, child_imat, a, obmat);
 
     const float w = 1.0f / (float)mp->totloop;
     if (orco) {
@@ -713,51 +886,92 @@ static void make_child_duplis_faces(const DupliContext *ctx, void *userdata, Obj
         madd_v2_v2fl(dob->uv, mloopuv[mp->loopstart + j].uv, w);
       }
     }
-
-    /* recursion */
-    make_recursive_duplis(ctx, inst_ob, space_mat, a);
   }
 }
 
-static void make_duplis_faces(const DupliContext *ctx)
+static void make_child_duplis_faces_from_bmesh(const DupliContext *ctx,
+                                               void *userdata,
+                                               Object *child)
 {
-  Object *parent = ctx->object;
-  FaceDupliData fdd;
+  FaceDupliData_BMesh *fdd = userdata;
+  BMEditMesh *em = fdd->em;
+  float child_imat[4][4];
+  int a;
+  BMFace *f;
+  BMIter iter;
 
-  fdd.use_scale = ((parent->transflag & OB_DUPLIFACES_SCALE) != 0);
+  const float(*vert_coords)[3] = fdd->vert_coords;
 
-  /* gather mesh info */
-  {
-    BMEditMesh *em = BKE_editmesh_from_object(parent);
-
-    /* We do not need any render-smecific handling anymore, depsgraph takes care of that. */
-    /* NOTE: Do direct access to the evaluated mesh: this function is used
-     * during meta balls evaluation. But even without those all the objects
-     * which are needed for correct instancing are already evaluated. */
-    if (em != NULL) {
-      fdd.me_eval = em->mesh_eval_cage;
+  BLI_assert((vert_coords == NULL) || (em->bm->elem_index_dirty & BM_VERT) == 0);
+
+  invert_m4_m4(child->imat, child->obmat);
+  /* Relative transform from parent to child space. */
+  mul_m4_m4m4(child_imat, child->imat, ctx->object->obmat);
+  const float scale_fac = ctx->object->instance_faces_scale;
+
+  BM_ITER_MESH_INDEX (f, &iter, em->bm, BM_FACES_OF_MESH, a) {
+    float obmat[4][4];
+
+    /* `obmat` is transform to face. */
+    get_dupliface_transform_from_bmesh(f, vert_coords, fdd->use_scale, scale_fac, obmat);
+    DupliObject *dob = face_dupli(ctx, child, child_imat, a, obmat);
+
+    if (fdd->has_orco) {
+      const float w = 1.0f / (float)f->len;
+      BMLoop *l_first, *l_iter;
+      l_iter = l_first = BM_FACE_FIRST_LOOP(f);
+      do {
+        madd_v3_v3fl(dob->orco, l_iter->v->co, w);
+      } while ((l_iter = l_iter->next) != l_first);
     }
-    else {
-      fdd.me_eval = BKE_object_get_evaluated_mesh(parent);
+    if (fdd->has_uvs) {
+      BM_face_uv_calc_center_median(f, fdd->cd_loop_uv_offset, dob->uv);
     }
+  }
+}
 
-    if (fdd.me_eval == NULL) {
-      return;
-    }
+static void make_duplis_faces(const DupliContext *ctx)
+{
+  Object *parent = ctx->object;
+  const bool use_scale = ((parent->transflag & OB_DUPLIFACES_SCALE) != 0);
+
+  /* Gather mesh info. */
+  BMEditMesh *em = NULL;
+  const float(*vert_coords)[3] = NULL;
+  Mesh *me_eval = mesh_data_from_duplicator_object(parent, &em, &vert_coords, NULL);
+  if (em == NULL && me_eval == NULL) {
+    return;
+  }
 
+  if (em != NULL) {
+    FaceDupliData_BMesh fdd = {
+        .em = em,
+        .use_scale = use_scale,
+        .has_orco = (vert_coords != NULL),
+        .vert_coords = vert_coords,
+    };
+    const int uv_idx = CustomData_get_render_layer(&em->bm->ldata, CD_MLOOPUV);
+    if (uv_idx != -1) {
+      fdd.has_uvs = true;
+      fdd.cd_loop_uv_offset = CustomData_get_n_offset(&em->bm->ldata, CD_MLOOPUV, uv_idx);
+    }
+    make_child_duplis(ctx, &fdd, make_child_duplis_faces_from_bmesh);
+  }
+  else {
+    FaceDupliData_Mesh fdd = {
+        .use_scale = use_scale,
+        .me_eval = me_eval,
+    };
     fdd.orco = CustomData_get_layer(&fdd.me_eval->vdata, CD_ORCO);
     const int uv_idx = CustomData_get_render_layer(&fdd.me_eval->ldata, CD_MLOOPUV);
     fdd.mloopuv = CustomData_get_layer_n(&fdd.me_eval->ldata, CD_MLOOPUV, uv_idx);
 
-    fdd.totface = fdd.me_eval->totpoly;
-    fdd.mpoly = fdd.me_eval->mpoly;
-    fdd.mloop = fdd.me_eval->mloop;
-    fdd.mvert = fdd.me_eval->mvert;
+    fdd.totface = me_eval->totpoly;
+    fdd.mpoly = me_eval->mpoly;
+    fdd.mloop = me_eval->mloop;
+    fdd.mvert = me_eval->mvert;
+    make_child_duplis(ctx, &fdd, make_child_duplis_faces_from_mesh);
   }
-
-  make_child_duplis(ctx, &fdd, make_child_duplis_faces);
-
-  fdd.me_eval = NULL;
 }
 
 static const DupliGenerator gen_dupli_faces = {