Metaball: Evaluate metaball objects as mesh components

With the ultimate goal of simplifying drawing and evaluation,
this patch makes the following changes and removes code:
- Use `Mesh` instead of `DispList` for evaluated basis metaballs.
- Remove all `DispList` drawing code, which is now unused.
- Simplify code that converts evaluated metaballs to meshes.
- Store the evaluated mesh in the evaluated geometry set.

This has the following indirect benefits:
- Evaluated meshes from metaball objects can be used in geometry nodes.
- Renderers can ignore evaluated metaball objects completely
- Cycles rendering no longer has to convert to mesh from `DispList`.
- We get closer to removing `DispList` completely.
- Optimizations to mesh rendering will also apply to metaball objects.

The vertex normals on the evaluated mesh are technically invalid;
the regular calculation wouldn't reproduce them. Metaball objects
don't support modifiers though, so it shouldn't be a problem.
Eventually we can support per-vertex custom normals (T93551).

Differential Revision: https://developer.blender.org/D14593

14 files changed, 38 insertions, 758 deletions

diff --git a/source/blender/draw/CMakeLists.txt b/source/blender/draw/CMakeLists.txt
index 0a62263ce3b..684134609c9 100644
--- a/source/blender/draw/CMakeLists.txt
+++ b/source/blender/draw/CMakeLists.txt
@@ -71,11 +71,9 @@ set(SRC
   intern/draw_attributes.cc
   intern/draw_cache_impl_curve.cc
   intern/draw_cache_impl_curves.cc
-  intern/draw_cache_impl_displist.c
   intern/draw_cache_impl_gpencil.c
   intern/draw_cache_impl_lattice.c
   intern/draw_cache_impl_mesh.cc
-  intern/draw_cache_impl_metaball.c
   intern/draw_cache_impl_particles.c
   intern/draw_cache_impl_pointcloud.cc
   intern/draw_cache_impl_subdivision.cc
diff --git a/source/blender/draw/engines/eevee/eevee_engine.c b/source/blender/draw/engines/eevee/eevee_engine.c
index ffe0863fb9f..cc7d0c6b22e 100644
--- a/source/blender/draw/engines/eevee/eevee_engine.c
+++ b/source/blender/draw/engines/eevee/eevee_engine.c
@@ -109,7 +109,7 @@ void EEVEE_cache_populate(void *vedata, Object *ob)
   }
 
   if (DRW_object_is_renderable(ob) && (ob_visibility & OB_VISIBLE_SELF)) {
-    if (ELEM(ob->type, OB_MESH, OB_SURF, OB_MBALL)) {
+    if (ELEM(ob->type, OB_MESH, OB_SURF)) {
       EEVEE_materials_cache_populate(vedata, sldata, ob, &cast_shadow);
     }
     else if (ob->type == OB_CURVES) {
diff --git a/source/blender/draw/engines/eevee/eevee_materials.c b/source/blender/draw/engines/eevee/eevee_materials.c
index efd27c19654..94f29d64628 100644
--- a/source/blender/draw/engines/eevee/eevee_materials.c
+++ b/source/blender/draw/engines/eevee/eevee_materials.c
@@ -806,7 +806,7 @@ void EEVEE_materials_cache_populate(EEVEE_Data *vedata,
                          !DRW_state_is_image_render();
 
   /* First get materials for this mesh. */
-  if (ELEM(ob->type, OB_MESH, OB_SURF, OB_MBALL)) {
+  if (ELEM(ob->type, OB_MESH, OB_SURF)) {
     const int materials_len = DRW_cache_object_material_count_get(ob);
 
     EeveeMaterialCache *matcache = BLI_array_alloca(matcache, materials_len);
diff --git a/source/blender/draw/engines/eevee/eevee_render.c b/source/blender/draw/engines/eevee/eevee_render.c
index 82944f237ea..3e268758076 100644
--- a/source/blender/draw/engines/eevee/eevee_render.c
+++ b/source/blender/draw/engines/eevee/eevee_render.c
@@ -224,7 +224,7 @@ void EEVEE_render_cache(void *vedata,
   }
 
   if (ob_visibility & OB_VISIBLE_SELF) {
-    if (ELEM(ob->type, OB_MESH, OB_SURF, OB_MBALL)) {
+    if (ELEM(ob->type, OB_MESH, OB_SURF)) {
       EEVEE_materials_cache_populate(vedata, sldata, ob, &cast_shadow);
       if (do_cryptomatte) {
         EEVEE_cryptomatte_cache_populate(data, sldata, ob);
diff --git a/source/blender/draw/engines/eevee_next/eevee_instance.cc b/source/blender/draw/engines/eevee_next/eevee_instance.cc
index 6665b3a7c9b..eb32ebe9555 100644
--- a/source/blender/draw/engines/eevee_next/eevee_instance.cc
+++ b/source/blender/draw/engines/eevee_next/eevee_instance.cc
@@ -144,8 +144,7 @@ void Instance::object_sync(Object *ob)
       case OB_MESH:
       case OB_CURVES_LEGACY:
       case OB_SURF:
-      case OB_FONT:
-      case OB_MBALL: {
+      case OB_FONT: {
         sync.sync_mesh(ob, ob_handle);
         break;
       }
diff --git a/source/blender/draw/engines/overlay/overlay_engine.c b/source/blender/draw/engines/overlay/overlay_engine.c
index 5edd68bffff..6e2da95e405 100644
--- a/source/blender/draw/engines/overlay/overlay_engine.c
+++ b/source/blender/draw/engines/overlay/overlay_engine.c
@@ -320,7 +320,6 @@ static void OVERLAY_cache_populate(void *vedata, Object *ob)
                                 OB_MESH,
                                 OB_CURVES_LEGACY,
                                 OB_SURF,
-                                OB_MBALL,
                                 OB_FONT,
                                 OB_GPENCIL,
                                 OB_CURVES,
diff --git a/source/blender/draw/engines/workbench/workbench_engine.c b/source/blender/draw/engines/workbench/workbench_engine.c
index 9eb35c25bf4..ad32618e636 100644
--- a/source/blender/draw/engines/workbench/workbench_engine.c
+++ b/source/blender/draw/engines/workbench/workbench_engine.c
@@ -409,7 +409,7 @@ void workbench_cache_populate(void *ved, Object *ob)
     return;
   }
 
-  if (ELEM(ob->type, OB_MESH, OB_SURF, OB_MBALL, OB_POINTCLOUD)) {
+  if (ELEM(ob->type, OB_MESH, OB_SURF, OB_POINTCLOUD)) {
     bool use_sculpt_pbvh, use_texpaint_mode, draw_shadow, has_transp_mat = false;
     eV3DShadingColorType color_type = workbench_color_type_get(
         wpd, ob, &use_sculpt_pbvh, &use_texpaint_mode, &draw_shadow);
diff --git a/source/blender/draw/intern/draw_cache.c b/source/blender/draw/intern/draw_cache.c
index 4c0f025e934..275392ec56a 100644
--- a/source/blender/draw/intern/draw_cache.c
+++ b/source/blender/draw/intern/draw_cache.c
@@ -780,6 +780,39 @@ GPUBatch *DRW_cache_normal_arrow_get(void)
   return SHC.drw_normal_arrow;
 }
 
+void DRW_vertbuf_create_wiredata(GPUVertBuf *vbo, const int vert_len)
+{
+  static GPUVertFormat format = {0};
+  static struct {
+    uint wd;
+  } attr_id;
+  if (format.attr_len == 0) {
+    /* initialize vertex format */
+    if (!GPU_crappy_amd_driver()) {
+      /* Some AMD drivers strangely crash with a vbo with this format. */
+      attr_id.wd = GPU_vertformat_attr_add(
+          &format, "wd", GPU_COMP_U8, 1, GPU_FETCH_INT_TO_FLOAT_UNIT);
+    }
+    else {
+      attr_id.wd = GPU_vertformat_attr_add(&format, "wd", GPU_COMP_F32, 1, GPU_FETCH_FLOAT);
+    }
+  }
+
+  GPU_vertbuf_init_with_format(vbo, &format);
+  GPU_vertbuf_data_alloc(vbo, vert_len);
+
+  if (GPU_vertbuf_get_format(vbo)->stride == 1) {
+    memset(GPU_vertbuf_get_data(vbo), 0xFF, (size_t)vert_len);
+  }
+  else {
+    GPUVertBufRaw wd_step;
+    GPU_vertbuf_attr_get_raw_data(vbo, attr_id.wd, &wd_step);
+    for (int i = 0; i < vert_len; i++) {
+      *((float *)GPU_vertbuf_raw_step(&wd_step)) = 1.0f;
+    }
+  }
+}
+
 /** \} */
 
 /* -------------------------------------------------------------------- */
@@ -836,8 +869,6 @@ GPUBatch *DRW_cache_object_edge_detection_get(Object *ob, bool *r_is_manifold)
       return NULL;
     case OB_FONT:
       return NULL;
-    case OB_MBALL:
-      return DRW_cache_mball_edge_detection_get(ob, r_is_manifold);
     case OB_CURVES:
       return NULL;
     case OB_POINTCLOUD:
@@ -860,8 +891,6 @@ GPUBatch *DRW_cache_object_face_wireframe_get(Object *ob)
       return NULL;
     case OB_FONT:
       return NULL;
-    case OB_MBALL:
-      return DRW_cache_mball_face_wireframe_get(ob);
     case OB_CURVES:
       return NULL;
     case OB_POINTCLOUD:
@@ -887,8 +916,6 @@ GPUBatch *DRW_cache_object_loose_edges_get(struct Object *ob)
       return NULL;
     case OB_FONT:
       return NULL;
-    case OB_MBALL:
-      return NULL;
     case OB_CURVES:
       return NULL;
     case OB_POINTCLOUD:
@@ -911,8 +938,6 @@ GPUBatch *DRW_cache_object_surface_get(Object *ob)
       return NULL;
     case OB_FONT:
       return NULL;
-    case OB_MBALL:
-      return DRW_cache_mball_surface_get(ob);
     case OB_CURVES:
       return NULL;
     case OB_POINTCLOUD:
@@ -936,8 +961,6 @@ GPUVertBuf *DRW_cache_object_pos_vertbuf_get(Object *ob)
     case OB_SURF:
     case OB_FONT:
       return NULL;
-    case OB_MBALL:
-      return DRW_mball_batch_cache_pos_vertbuf_get(ob);
     case OB_CURVES:
       return NULL;
     case OB_POINTCLOUD:
@@ -968,8 +991,6 @@ int DRW_cache_object_material_count_get(struct Object *ob)
     case OB_SURF:
     case OB_FONT:
       return DRW_curve_material_count_get(ob->data);
-    case OB_MBALL:
-      return DRW_metaball_material_count_get(ob->data);
     case OB_CURVES:
       return DRW_curves_material_count_get(ob->data);
     case OB_POINTCLOUD:
@@ -997,8 +1018,6 @@ GPUBatch **DRW_cache_object_surface_material_get(struct Object *ob,
       return NULL;
     case OB_FONT:
       return NULL;
-    case OB_MBALL:
-      return DRW_cache_mball_surface_shaded_get(ob, gpumat_array, gpumat_array_len);
     case OB_CURVES:
       return NULL;
     case OB_POINTCLOUD:
@@ -2972,39 +2991,6 @@ GPUBatch *DRW_cache_curve_vert_overlay_get(Object *ob)
 /** \} */
 
 /* -------------------------------------------------------------------- */
-/** \name MetaBall
- * \{ */
-
-GPUBatch *DRW_cache_mball_surface_get(Object *ob)
-{
-  BLI_assert(ob->type == OB_MBALL);
-  return DRW_metaball_batch_cache_get_triangles_with_normals(ob);
-}
-
-GPUBatch *DRW_cache_mball_edge_detection_get(Object *ob, bool *r_is_manifold)
-{
-  BLI_assert(ob->type == OB_MBALL);
-  return DRW_metaball_batch_cache_get_edge_detection(ob, r_is_manifold);
-}
-
-GPUBatch *DRW_cache_mball_face_wireframe_get(Object *ob)
-{
-  BLI_assert(ob->type == OB_MBALL);
-  return DRW_metaball_batch_cache_get_wireframes_face(ob);
-}
-
-GPUBatch **DRW_cache_mball_surface_shaded_get(Object *ob,
-                                              struct GPUMaterial **gpumat_array,
-                                              uint gpumat_array_len)
-{
-  BLI_assert(ob->type == OB_MBALL);
-  MetaBall *mb = ob->data;
-  return DRW_metaball_batch_cache_get_surface_shaded(ob, mb, gpumat_array, gpumat_array_len);
-}
-
-/** \} */
-
-/* -------------------------------------------------------------------- */
 /** \name Font
  * \{ */
 
@@ -3322,9 +3308,6 @@ void drw_batch_cache_validate(Object *ob)
     case OB_SURF:
       DRW_curve_batch_cache_validate((Curve *)ob->data);
       break;
-    case OB_MBALL:
-      DRW_mball_batch_cache_validate((MetaBall *)ob->data);
-      break;
     case OB_LATTICE:
       DRW_lattice_batch_cache_validate((Lattice *)ob->data);
       break;
diff --git a/source/blender/draw/intern/draw_cache.h b/source/blender/draw/intern/draw_cache.h
index a107eb7c75c..4e8788ada08 100644
--- a/source/blender/draw/intern/draw_cache.h
+++ b/source/blender/draw/intern/draw_cache.h
@@ -213,15 +213,6 @@ struct GPUBatch *DRW_cache_particles_get_edit_tip_points(struct Object *object,
                                                          struct PTCacheEdit *edit);
 struct GPUBatch *DRW_cache_particles_get_prim(int type);
 
-/* Metaball */
-
-struct GPUBatch *DRW_cache_mball_surface_get(struct Object *ob);
-struct GPUBatch **DRW_cache_mball_surface_shaded_get(struct Object *ob,
-                                                     struct GPUMaterial **gpumat_array,
-                                                     uint gpumat_array_len);
-struct GPUBatch *DRW_cache_mball_face_wireframe_get(struct Object *ob);
-struct GPUBatch *DRW_cache_mball_edge_detection_get(struct Object *ob, bool *r_is_manifold);
-
 /* Curves */
 
 struct GPUBatch *DRW_cache_curves_surface_get(struct Object *ob);
diff --git a/source/blender/draw/intern/draw_cache_impl.h b/source/blender/draw/intern/draw_cache_impl.h
index 91dbef8d7b1..7f7d0a7613f 100644
--- a/source/blender/draw/intern/draw_cache_impl.h
+++ b/source/blender/draw/intern/draw_cache_impl.h
@@ -36,10 +36,6 @@ extern "C" {
 /** \name Expose via BKE callbacks
  * \{ */
 
-void DRW_mball_batch_cache_dirty_tag(struct MetaBall *mb, int mode);
-void DRW_mball_batch_cache_validate(struct MetaBall *mb);
-void DRW_mball_batch_cache_free(struct MetaBall *mb);
-
 void DRW_curve_batch_cache_dirty_tag(struct Curve *cu, int mode);
 void DRW_curve_batch_cache_validate(struct Curve *cu);
 void DRW_curve_batch_cache_free(struct Curve *cu);
@@ -111,39 +107,6 @@ struct GPUBatch *DRW_curve_batch_cache_get_edit_verts(struct Curve *cu);
 /** \} */
 
 /* -------------------------------------------------------------------- */
-/** \name Metaball
- * \{ */
-
-int DRW_metaball_material_count_get(struct MetaBall *mb);
-
-struct GPUBatch *DRW_metaball_batch_cache_get_triangles_with_normals(struct Object *ob);
-struct GPUBatch **DRW_metaball_batch_cache_get_surface_shaded(struct Object *ob,
-                                                              struct MetaBall *mb,
-                                                              struct GPUMaterial **gpumat_array,
-                                                              uint gpumat_array_len);
-struct GPUBatch *DRW_metaball_batch_cache_get_wireframes_face(struct Object *ob);
-struct GPUBatch *DRW_metaball_batch_cache_get_edge_detection(struct Object *ob,
-                                                             bool *r_is_manifold);
-
-/** \} */
-
-/* -------------------------------------------------------------------- */
-/** \name DispList
- * \{ */
-
-void DRW_displist_vertbuf_create_pos_and_nor(struct ListBase *lb,
-                                             struct GPUVertBuf *vbo,
-                                             const struct Scene *scene);
-void DRW_displist_vertbuf_create_wiredata(struct ListBase *lb, struct GPUVertBuf *vbo);
-void DRW_displist_indexbuf_create_lines_in_order(struct ListBase *lb, struct GPUIndexBuf *ibo);
-void DRW_displist_indexbuf_create_triangles_in_order(struct ListBase *lb, struct GPUIndexBuf *ibo);
-void DRW_displist_indexbuf_create_edges_adjacency_lines(struct ListBase *lb,
-                                                        struct GPUIndexBuf *ibo,
-                                                        bool *r_is_manifold);
-
-/** \} */
-
-/* -------------------------------------------------------------------- */
 /** \name Lattice
  * \{ */
 
@@ -309,7 +272,6 @@ struct GPUBatch *DRW_mesh_batch_cache_get_edit_mesh_analysis(struct Mesh *me);
  * \{ */
 
 struct GPUVertBuf *DRW_mesh_batch_cache_pos_vertbuf_get(struct Mesh *me);
-struct GPUVertBuf *DRW_mball_batch_cache_pos_vertbuf_get(struct Object *ob);
 
 int DRW_mesh_material_count_get(const struct Object *object, const struct Mesh *me);
 
diff --git a/source/blender/draw/intern/draw_cache_impl_displist.c b/source/blender/draw/intern/draw_cache_impl_displist.c
deleted file mode 100644
index 96c088c3ee9..00000000000
--- a/source/blender/draw/intern/draw_cache_impl_displist.c
+++ /dev/null
@@ -1,354 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-or-later
- * Copyright 2017 Blender Foundation. All rights reserved. */
-
-/** \file
- * \ingroup draw
- *
- * \brief DispList API for render engines
- *
- * \note DispList may be removed soon! This is a utility for object types that use render.
- */
-
-#include "BLI_edgehash.h"
-#include "BLI_listbase.h"
-#include "BLI_math_vector.h"
-#include "BLI_utildefines.h"
-
-#include "DNA_curve_types.h"
-#include "DNA_scene_types.h"
-
-#include "BKE_displist.h"
-
-#include "GPU_batch.h"
-#include "GPU_capabilities.h"
-
-#include "draw_cache_inline.h"
-
-#include "draw_cache_impl.h" /* own include */
-
-static int dl_vert_len(const DispList *dl)
-{
-  switch (dl->type) {
-    case DL_INDEX3:
-    case DL_INDEX4:
-      return dl->nr;
-    case DL_SURF:
-      return dl->parts * dl->nr;
-  }
-  return 0;
-}
-
-static int dl_tri_len(const DispList *dl)
-{
-  switch (dl->type) {
-    case DL_INDEX3:
-      return dl->parts;
-    case DL_INDEX4:
-      return dl->parts * 2;
-    case DL_SURF:
-      return dl->totindex * 2;
-  }
-  return 0;
-}
-
-/* see: displist_vert_coords_alloc */
-static int curve_render_surface_vert_len_get(const ListBase *lb)
-{
-  int vert_len = 0;
-  LISTBASE_FOREACH (const DispList *, dl, lb) {
-    vert_len += dl_vert_len(dl);
-  }
-  return vert_len;
-}
-
-static int curve_render_surface_tri_len_get(const ListBase *lb)
-{
-  int tri_len = 0;
-  LISTBASE_FOREACH (const DispList *, dl, lb) {
-    tri_len += dl_tri_len(dl);
-  }
-  return tri_len;
-}
-
-typedef void(SetTriIndicesFn)(void *thunk, uint v1, uint v2, uint v3);
-
-static void displist_indexbufbuilder_set(
-    SetTriIndicesFn *set_tri_indices,
-    SetTriIndicesFn *set_quad_tri_indices, /* meh, find a better solution. */
-    void *thunk,
-    const DispList *dl,
-    const int ofs)
-{
-  if (ELEM(dl->type, DL_INDEX3, DL_INDEX4, DL_SURF)) {
-    const int *idx = dl->index;
-    if (dl->type == DL_INDEX3) {
-      const int i_end = dl->parts;
-      for (int i = 0; i < i_end; i++, idx += 3) {
-        set_tri_indices(thunk, idx[0] + ofs, idx[2] + ofs, idx[1] + ofs);
-      }
-    }
-    else if (dl->type == DL_SURF) {
-      const int i_end = dl->totindex;
-      for (int i = 0; i < i_end; i++, idx += 4) {
-        set_quad_tri_indices(thunk, idx[0] + ofs, idx[2] + ofs, idx[1] + ofs);
-        set_quad_tri_indices(thunk, idx[2] + ofs, idx[0] + ofs, idx[3] + ofs);
-      }
-    }
-    else {
-      BLI_assert(dl->type == DL_INDEX4);
-      const int i_end = dl->parts;
-      for (int i = 0; i < i_end; i++, idx += 4) {
-        if (idx[2] != idx[3]) {
-          set_quad_tri_indices(thunk, idx[2] + ofs, idx[0] + ofs, idx[1] + ofs);
-          set_quad_tri_indices(thunk, idx[0] + ofs, idx[2] + ofs, idx[3] + ofs);
-        }
-        else {
-          set_tri_indices(thunk, idx[2] + ofs, idx[0] + ofs, idx[1] + ofs);
-        }
-      }
-    }
-  }
-}
-
-void DRW_displist_vertbuf_create_pos_and_nor(ListBase *lb, GPUVertBuf *vbo, const Scene *scene)
-{
-  const bool do_hq_normals = (scene->r.perf_flag & SCE_PERF_HQ_NORMALS) != 0 ||
-                             GPU_use_hq_normals_workaround();
-
-  static GPUVertFormat format = {0};
-  static GPUVertFormat format_hq = {0};
-  static struct {
-    uint pos, nor;
-    uint pos_hq, nor_hq;
-  } attr_id;
-  if (format.attr_len == 0) {
-    /* initialize vertex format */
-    attr_id.pos = GPU_vertformat_attr_add(&format, "pos", GPU_COMP_F32, 3, GPU_FETCH_FLOAT);
-    attr_id.nor = GPU_vertformat_attr_add(
-        &format, "nor", GPU_COMP_I10, 4, GPU_FETCH_INT_TO_FLOAT_UNIT);
-    /* initialize vertex format */
-    attr_id.pos_hq = GPU_vertformat_attr_add(&format_hq, "pos", GPU_COMP_F32, 3, GPU_FETCH_FLOAT);
-    attr_id.nor_hq = GPU_vertformat_attr_add(
-        &format_hq, "nor", GPU_COMP_I16, 3, GPU_FETCH_INT_TO_FLOAT_UNIT);
-  }
-
-  uint pos_id = do_hq_normals ? attr_id.pos_hq : attr_id.pos;
-  uint nor_id = do_hq_normals ? attr_id.nor_hq : attr_id.nor;
-
-  GPU_vertbuf_init_with_format(vbo, do_hq_normals ? &format_hq : &format);
-  GPU_vertbuf_data_alloc(vbo, curve_render_surface_vert_len_get(lb));
-
-  BKE_displist_normals_add(lb);
-
-  int vbo_len_used = 0;
-  LISTBASE_FOREACH (const DispList *, dl, lb) {
-    const bool ndata_is_single = dl->type == DL_INDEX3;
-    if (ELEM(dl->type, DL_INDEX3, DL_INDEX4, DL_SURF)) {
-      const float *fp_co = dl->verts;
-      const float *fp_no = dl->nors;
-      const int vbo_end = vbo_len_used + dl_vert_len(dl);
-      while (vbo_len_used < vbo_end) {
-        GPU_vertbuf_attr_set(vbo, pos_id, vbo_len_used, fp_co);
-        if (fp_no) {
-          GPUNormal vnor_pack;
-          GPU_normal_convert_v3(&vnor_pack, fp_no, do_hq_normals);
-          GPU_vertbuf_attr_set(vbo, nor_id, vbo_len_used, &vnor_pack);
-          if (ndata_is_single == false) {
-            fp_no += 3;
-          }
-        }
-        fp_co += 3;
-        vbo_len_used += 1;
-      }
-    }
-  }
-}
-
-void DRW_vertbuf_create_wiredata(GPUVertBuf *vbo, const int vert_len)
-{
-  static GPUVertFormat format = {0};
-  static struct {
-    uint wd;
-  } attr_id;
-  if (format.attr_len == 0) {
-    /* initialize vertex format */
-    if (!GPU_crappy_amd_driver()) {
-      /* Some AMD drivers strangely crash with a vbo with this format. */
-      attr_id.wd = GPU_vertformat_attr_add(
-          &format, "wd", GPU_COMP_U8, 1, GPU_FETCH_INT_TO_FLOAT_UNIT);
-    }
-    else {
-      attr_id.wd = GPU_vertformat_attr_add(&format, "wd", GPU_COMP_F32, 1, GPU_FETCH_FLOAT);
-    }
-  }
-
-  GPU_vertbuf_init_with_format(vbo, &format);
-  GPU_vertbuf_data_alloc(vbo, vert_len);
-
-  if (GPU_vertbuf_get_format(vbo)->stride == 1) {
-    memset(GPU_vertbuf_get_data(vbo), 0xFF, (size_t)vert_len);
-  }
-  else {
-    GPUVertBufRaw wd_step;
-    GPU_vertbuf_attr_get_raw_data(vbo, attr_id.wd, &wd_step);
-    for (int i = 0; i < vert_len; i++) {
-      *((float *)GPU_vertbuf_raw_step(&wd_step)) = 1.0f;
-    }
-  }
-}
-
-void DRW_displist_vertbuf_create_wiredata(ListBase *lb, GPUVertBuf *vbo)
-{
-  const int vert_len = curve_render_surface_vert_len_get(lb);
-  DRW_vertbuf_create_wiredata(vbo, vert_len);
-}
-
-void DRW_displist_indexbuf_create_triangles_in_order(ListBase *lb, GPUIndexBuf *ibo)
-{
-  const int tri_len = curve_render_surface_tri_len_get(lb);
-  const int vert_len = curve_render_surface_vert_len_get(lb);
-
-  GPUIndexBufBuilder elb;
-  GPU_indexbuf_init(&elb, GPU_PRIM_TRIS, tri_len, vert_len);
-
-  int ofs = 0;
-  LISTBASE_FOREACH (const DispList *, dl, lb) {
-    displist_indexbufbuilder_set((SetTriIndicesFn *)GPU_indexbuf_add_tri_verts,
-                                 (SetTriIndicesFn *)GPU_indexbuf_add_tri_verts,
-                                 &elb,
-                                 dl,
-                                 ofs);
-    ofs += dl_vert_len(dl);
-  }
-
-  GPU_indexbuf_build_in_place(&elb, ibo);
-}
-
-static void set_overlay_wires_tri_indices(void *thunk, uint v1, uint v2, uint v3)
-{
-  GPUIndexBufBuilder *eld = (GPUIndexBufBuilder *)thunk;
-  GPU_indexbuf_add_line_verts(eld, v1, v2);
-  GPU_indexbuf_add_line_verts(eld, v2, v3);
-  GPU_indexbuf_add_line_verts(eld, v3, v1);
-}
-
-static void set_overlay_wires_quad_tri_indices(void *thunk, uint v1, uint v2, uint v3)
-{
-  GPUIndexBufBuilder *eld = (GPUIndexBufBuilder *)thunk;
-  GPU_indexbuf_add_line_verts(eld, v1, v3);
-  GPU_indexbuf_add_line_verts(eld, v3, v2);
-}
-
-void DRW_displist_indexbuf_create_lines_in_order(ListBase *lb, GPUIndexBuf *ibo)
-{
-  const int tri_len = curve_render_surface_tri_len_get(lb);
-  const int vert_len = curve_render_surface_vert_len_get(lb);
-
-  GPUIndexBufBuilder elb;
-  GPU_indexbuf_init(&elb, GPU_PRIM_LINES, tri_len * 3, vert_len);
-
-  int ofs = 0;
-  LISTBASE_FOREACH (const DispList *, dl, lb) {
-    displist_indexbufbuilder_set(
-        set_overlay_wires_tri_indices, set_overlay_wires_quad_tri_indices, &elb, dl, ofs);
-    ofs += dl_vert_len(dl);
-  }
-
-  GPU_indexbuf_build_in_place(&elb, ibo);
-}
-
-/* Edge detection/adjacency. */
-#define NO_EDGE INT_MAX
-static void set_edge_adjacency_lines_indices(
-    EdgeHash *eh, GPUIndexBufBuilder *elb, bool *r_is_manifold, uint v1, uint v2, uint v3)
-{
-  bool inv_indices = (v2 > v3);
-  void **pval;
-  bool value_is_init = BLI_edgehash_ensure_p(eh, v2, v3, &pval);
-  int v_data = POINTER_AS_INT(*pval);
-  if (!value_is_init || v_data == NO_EDGE) {
-    /* Save the winding order inside the sign bit. Because the
-     * edgehash sort the keys and we need to compare winding later. */
-    int value = (int)v1 + 1; /* Int 0 bm_looptricannot be signed */
-    *pval = POINTER_FROM_INT((inv_indices) ? -value : value);
-  }
-  else {
-    /* HACK Tag as not used. Prevent overhead of BLI_edgehash_remove. */
-    *pval = POINTER_FROM_INT(NO_EDGE);
-    bool inv_opposite = (v_data < 0);
-    uint v_opposite = (uint)abs(v_data) - 1;
-
-    if (inv_opposite == inv_indices) {
-      /* Don't share edge if triangles have non matching winding. */
-      GPU_indexbuf_add_line_adj_verts(elb, v1, v2, v3, v1);
-      GPU_indexbuf_add_line_adj_verts(elb, v_opposite, v2, v3, v_opposite);
-      *r_is_manifold = false;
-    }
-    else {
-      GPU_indexbuf_add_line_adj_verts(elb, v1, v2, v3, v_opposite);
-    }
-  }
-}
-
-static void set_edges_adjacency_lines_indices(void *thunk, uint v1, uint v2, uint v3)
-{
-  void **packed = (void **)thunk;
-  GPUIndexBufBuilder *elb = (GPUIndexBufBuilder *)packed[0];
-  EdgeHash *eh = (EdgeHash *)packed[1];
-  bool *r_is_manifold = (bool *)packed[2];
-
-  set_edge_adjacency_lines_indices(eh, elb, r_is_manifold, v1, v2, v3);
-  set_edge_adjacency_lines_indices(eh, elb, r_is_manifold, v2, v3, v1);
-  set_edge_adjacency_lines_indices(eh, elb, r_is_manifold, v3, v1, v2);
-}
-
-void DRW_displist_indexbuf_create_edges_adjacency_lines(struct ListBase *lb,
-                                                        struct GPUIndexBuf *ibo,
-                                                        bool *r_is_manifold)
-{
-  const int tri_len = curve_render_surface_tri_len_get(lb);
-  const int vert_len = curve_render_surface_vert_len_get(lb);
-
-  *r_is_manifold = true;
-
-  /* Allocate max but only used indices are sent to GPU. */
-  GPUIndexBufBuilder elb;
-  GPU_indexbuf_init(&elb, GPU_PRIM_LINES_ADJ, tri_len * 3, vert_len);
-
-  EdgeHash *eh = BLI_edgehash_new_ex(__func__, tri_len * 3);
-
-  /* pack values to pass to `set_edges_adjacency_lines_indices` function. */
-  void *thunk[3] = {&elb, eh, r_is_manifold};
-  int v_idx = 0;
-  LISTBASE_FOREACH (const DispList *, dl, lb) {
-    displist_indexbufbuilder_set((SetTriIndicesFn *)set_edges_adjacency_lines_indices,
-                                 (SetTriIndicesFn *)set_edges_adjacency_lines_indices,
-                                 thunk,
-                                 dl,
-                                 v_idx);
-    v_idx += dl_vert_len(dl);
-  }
-
-  /* Create edges for remaining non manifold edges. */
-  EdgeHashIterator *ehi;
-  for (ehi = BLI_edgehashIterator_new(eh); BLI_edgehashIterator_isDone(ehi) == false;
-       BLI_edgehashIterator_step(ehi)) {
-    uint v1, v2;
-    int v_data = POINTER_AS_INT(BLI_edgehashIterator_getValue(ehi));
-    if (v_data == NO_EDGE) {
-      continue;
-    }
-    BLI_edgehashIterator_getKey(ehi, &v1, &v2);
-    uint v0 = (uint)abs(v_data) - 1;
-    if (v_data < 0) { /* inv_opposite */
-      SWAP(uint, v1, v2);
-    }
-    GPU_indexbuf_add_line_adj_verts(&elb, v0, v1, v2, v0);
-    *r_is_manifold = false;
-  }
-  BLI_edgehashIterator_free(ehi);
-  BLI_edgehash_free(eh, NULL);
-
-  GPU_indexbuf_build_in_place(&elb, ibo);
-}
-#undef NO_EDGE
diff --git a/source/blender/draw/intern/draw_cache_impl_metaball.c b/source/blender/draw/intern/draw_cache_impl_metaball.c
deleted file mode 100644
index 1408dc91069..00000000000
--- a/source/blender/draw/intern/draw_cache_impl_metaball.c
+++ /dev/null
@@ -1,294 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-or-later
- * Copyright 2017 Blender Foundation. All rights reserved. */
-
-/** \file
- * \ingroup draw
- *
- * \brief MetaBall API for render engines
- */
-
-#include "MEM_guardedalloc.h"
-
-#include "BLI_math_base.h"
-#include "BLI_utildefines.h"
-
-#include "DNA_meta_types.h"
-#include "DNA_object_types.h"
-
-#include "BKE_curve.h"
-#include "BKE_mball.h"
-
-#include "GPU_batch.h"
-
-#include "DRW_render.h"
-#include "draw_cache_impl.h" /* own include */
-
-static void metaball_batch_cache_clear(MetaBall *mb);
-
-/* -------------------------------------------------------------------- */
-/** \name MetaBall GPUBatch Cache
- * \{ */
-
-typedef struct MetaBallBatchCache {
-  GPUBatch *batch;
-  GPUBatch **shaded_triangles;
-
-  int mat_len;
-
-  /* Shared */
-  GPUVertBuf *pos_nor_in_order;
-
-  /* Wireframe */
-  struct {
-    GPUBatch *batch;
-  } face_wire;
-
-  /* Edge detection */
-  GPUBatch *edge_detection;
-  GPUIndexBuf *edges_adj_lines;
-
-  /* settings to determine if cache is invalid */
-  bool is_dirty;
-
-  /* Valid only if edge_detection is up to date. */
-  bool is_manifold;
-} MetaBallBatchCache;
-
-/* GPUBatch cache management. */
-
-static bool metaball_batch_cache_valid(MetaBall *mb)
-{
-  MetaBallBatchCache *cache = mb->batch_cache;
-
-  if (cache == NULL) {
-    return false;
-  }
-
-  return cache->is_dirty == false;
-}
-
-static void metaball_batch_cache_init(MetaBall *mb)
-{
-  MetaBallBatchCache *cache = mb->batch_cache;
-
-  if (!cache) {
-    cache = mb->batch_cache = MEM_mallocN(sizeof(*cache), __func__);
-  }
-  cache->batch = NULL;
-  cache->mat_len = 0;
-  cache->shaded_triangles = NULL;
-  cache->is_dirty = false;
-  cache->pos_nor_in_order = NULL;
-  cache->face_wire.batch = NULL;
-  cache->edge_detection = NULL;
-  cache->edges_adj_lines = NULL;
-  cache->is_manifold = false;
-}
-
-void DRW_mball_batch_cache_validate(MetaBall *mb)
-{
-  if (!metaball_batch_cache_valid(mb)) {
-    metaball_batch_cache_clear(mb);
-    metaball_batch_cache_init(mb);
-  }
-}
-
-static MetaBallBatchCache *metaball_batch_cache_get(MetaBall *mb)
-{
-  return mb->batch_cache;
-}
-
-void DRW_mball_batch_cache_dirty_tag(MetaBall *mb, int mode)
-{
-  MetaBallBatchCache *cache = mb->batch_cache;
-  if (cache == NULL) {
-    return;
-  }
-  switch (mode) {
-    case BKE_MBALL_BATCH_DIRTY_ALL:
-      cache->is_dirty = true;
-      break;
-    default:
-      BLI_assert(0);
-  }
-}
-
-static void metaball_batch_cache_clear(MetaBall *mb)
-{
-  MetaBallBatchCache *cache = mb->batch_cache;
-  if (!cache) {
-    return;
-  }
-
-  GPU_BATCH_DISCARD_SAFE(cache->face_wire.batch);
-  GPU_BATCH_DISCARD_SAFE(cache->batch);
-  GPU_BATCH_DISCARD_SAFE(cache->edge_detection);
-  GPU_VERTBUF_DISCARD_SAFE(cache->pos_nor_in_order);
-  GPU_INDEXBUF_DISCARD_SAFE(cache->edges_adj_lines);
-  /* NOTE: shaded_triangles[0] is already freed by `cache->batch`. */
-  MEM_SAFE_FREE(cache->shaded_triangles);
-  cache->mat_len = 0;
-  cache->is_manifold = false;
-}
-
-void DRW_mball_batch_cache_free(MetaBall *mb)
-{
-  metaball_batch_cache_clear(mb);
-  MEM_SAFE_FREE(mb->batch_cache);
-}
-
-static GPUVertBuf *mball_batch_cache_get_pos_and_normals(Object *ob,
-                                                         MetaBallBatchCache *cache,
-                                                         const struct Scene *scene)
-{
-  if (cache->pos_nor_in_order == NULL) {
-    ListBase *lb = &ob->runtime.curve_cache->disp;
-    cache->pos_nor_in_order = GPU_vertbuf_calloc();
-    DRW_displist_vertbuf_create_pos_and_nor(lb, cache->pos_nor_in_order, scene);
-  }
-  return cache->pos_nor_in_order;
-}
-
-static GPUIndexBuf *mball_batch_cache_get_edges_adj_lines(Object *ob, MetaBallBatchCache *cache)
-{
-  if (cache->edges_adj_lines == NULL) {
-    ListBase *lb = &ob->runtime.curve_cache->disp;
-    cache->edges_adj_lines = GPU_indexbuf_calloc();
-    DRW_displist_indexbuf_create_edges_adjacency_lines(
-        lb, cache->edges_adj_lines, &cache->is_manifold);
-  }
-  return cache->edges_adj_lines;
-}
-
-/** \} */
-
-/* -------------------------------------------------------------------- */
-/** \name Public Object/MetaBall API
- * \{ */
-
-GPUBatch *DRW_metaball_batch_cache_get_triangles_with_normals(Object *ob)
-{
-  if (!BKE_mball_is_basis(ob)) {
-    return NULL;
-  }
-
-  MetaBall *mb = ob->data;
-  MetaBallBatchCache *cache = metaball_batch_cache_get(mb);
-  const DRWContextState *draw_ctx = DRW_context_state_get();
-  const struct Scene *scene = draw_ctx->scene;
-
-  if (cache->batch == NULL) {
-    ListBase *lb = &ob->runtime.curve_cache->disp;
-    GPUIndexBuf *ibo = GPU_indexbuf_calloc();
-    DRW_displist_indexbuf_create_triangles_in_order(lb, ibo);
-    cache->batch = GPU_batch_create_ex(GPU_PRIM_TRIS,
-                                       mball_batch_cache_get_pos_and_normals(ob, cache, scene),
-                                       ibo,
-                                       GPU_BATCH_OWNS_INDEX);
-  }
-
-  return cache->batch;
-}
-
-GPUBatch **DRW_metaball_batch_cache_get_surface_shaded(Object *ob,
-                                                       MetaBall *mb,
-                                                       struct GPUMaterial **UNUSED(gpumat_array),
-                                                       uint gpumat_array_len)
-{
-  if (!BKE_mball_is_basis(ob)) {
-    return NULL;
-  }
-
-  BLI_assert(gpumat_array_len == DRW_metaball_material_count_get(mb));
-
-  MetaBallBatchCache *cache = metaball_batch_cache_get(mb);
-  if (cache->shaded_triangles == NULL) {
-    cache->mat_len = gpumat_array_len;
-    cache->shaded_triangles = MEM_callocN(sizeof(*cache->shaded_triangles) * cache->mat_len,
-                                          __func__);
-    cache->shaded_triangles[0] = DRW_metaball_batch_cache_get_triangles_with_normals(ob);
-    for (int i = 1; i < cache->mat_len; i++) {
-      cache->shaded_triangles[i] = NULL;
-    }
-  }
-  return cache->shaded_triangles;
-}
-
-GPUBatch *DRW_metaball_batch_cache_get_wireframes_face(Object *ob)
-{
-  if (!BKE_mball_is_basis(ob)) {
-    return NULL;
-  }
-
-  MetaBall *mb = ob->data;
-  MetaBallBatchCache *cache = metaball_batch_cache_get(mb);
-  const DRWContextState *draw_ctx = DRW_context_state_get();
-  const struct Scene *scene = draw_ctx->scene;
-
-  if (cache->face_wire.batch == NULL) {
-    ListBase *lb = &ob->runtime.curve_cache->disp;
-
-    GPUVertBuf *vbo_wiredata = GPU_vertbuf_calloc();
-    DRW_displist_vertbuf_create_wiredata(lb, vbo_wiredata);
-
-    GPUIndexBuf *ibo = GPU_indexbuf_calloc();
-    DRW_displist_indexbuf_create_lines_in_order(lb, ibo);
-
-    cache->face_wire.batch = GPU_batch_create_ex(
-        GPU_PRIM_LINES,
-        mball_batch_cache_get_pos_and_normals(ob, cache, scene),
-        ibo,
-        GPU_BATCH_OWNS_INDEX);
-
-    GPU_batch_vertbuf_add_ex(cache->face_wire.batch, vbo_wiredata, true);
-  }
-
-  return cache->face_wire.batch;
-}
-
-struct GPUBatch *DRW_metaball_batch_cache_get_edge_detection(struct Object *ob,
-                                                             bool *r_is_manifold)
-{
-  if (!BKE_mball_is_basis(ob)) {
-    return NULL;
-  }
-
-  MetaBall *mb = ob->data;
-  MetaBallBatchCache *cache = metaball_batch_cache_get(mb);
-  const DRWContextState *draw_ctx = DRW_context_state_get();
-  const struct Scene *scene = draw_ctx->scene;
-
-  if (cache->edge_detection == NULL) {
-    cache->edge_detection = GPU_batch_create(
-        GPU_PRIM_LINES_ADJ,
-        mball_batch_cache_get_pos_and_normals(ob, cache, scene),
-        mball_batch_cache_get_edges_adj_lines(ob, cache));
-  }
-
-  if (r_is_manifold) {
-    *r_is_manifold = cache->is_manifold;
-  }
-
-  return cache->edge_detection;
-}
-
-struct GPUVertBuf *DRW_mball_batch_cache_pos_vertbuf_get(Object *ob)
-{
-  if (!BKE_mball_is_basis(ob)) {
-    return NULL;
-  }
-
-  MetaBall *mb = ob->data;
-  MetaBallBatchCache *cache = metaball_batch_cache_get(mb);
-  const DRWContextState *draw_ctx = DRW_context_state_get();
-  const struct Scene *scene = draw_ctx->scene;
-
-  return mball_batch_cache_get_pos_and_normals(ob, cache, scene);
-}
-
-int DRW_metaball_material_count_get(MetaBall *mb)
-{
-  return max_ii(1, mb->totcol);
-}
-
-/** \} */
diff --git a/source/blender/draw/intern/draw_common.c b/source/blender/draw/intern/draw_common.c
index 0f330dbb519..de56b34df78 100644
--- a/source/blender/draw/intern/draw_common.c
+++ b/source/blender/draw/intern/draw_common.c
@@ -417,7 +417,6 @@ bool DRW_object_is_flat(Object *ob, int *r_axis)
             OB_CURVES_LEGACY,
             OB_SURF,
             OB_FONT,
-            OB_MBALL,
             OB_CURVES,
             OB_POINTCLOUD,
             OB_VOLUME)) {
diff --git a/source/blender/draw/intern/draw_manager.c b/source/blender/draw/intern/draw_manager.c
index 4693e5f8e20..3be2ddf5173 100644
--- a/source/blender/draw/intern/draw_manager.c
+++ b/source/blender/draw/intern/draw_manager.c
@@ -2989,9 +2989,6 @@ void DRW_engines_register(void)
 
   /* setup callbacks */
   {
-    BKE_mball_batch_cache_dirty_tag_cb = DRW_mball_batch_cache_dirty_tag;
-    BKE_mball_batch_cache_free_cb = DRW_mball_batch_cache_free;
-
     BKE_curve_batch_cache_dirty_tag_cb = DRW_curve_batch_cache_dirty_tag;
     BKE_curve_batch_cache_free_cb = DRW_curve_batch_cache_free;