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

1 files changed, 1 insertions, 20 deletions

diff --git a/source/blender/blenkernel/BKE_mball.h b/source/blender/blenkernel/BKE_mball.h
index a23d010b51f..667a1044e7b 100644
--- a/source/blender/blenkernel/BKE_mball.h
+++ b/source/blender/blenkernel/BKE_mball.h
@@ -55,14 +55,6 @@ bool BKE_mball_is_basis(const struct Object *ob);
 struct Object *BKE_mball_basis_find(struct Scene *scene, struct Object *ob);
 
 /**
- * Compute bounding box of all meta-elements / meta-ball.
- *
- * Bounding box is computed from polygonized surface. \a ob is
- * basic meta-balls (with name `Meta` for example). All other meta-ball objects
- * (with names `Meta.001`, `Meta.002`, etc) are included in this bounding-box.
- */
-void BKE_mball_texspace_calc(struct Object *ob);
-/**
  * Return or compute bounding-box for given meta-ball object.
  */
 struct BoundBox *BKE_mball_boundbox_get(struct Object *ob);
@@ -110,18 +102,7 @@ bool BKE_mball_select_swap_multi_ex(struct Base **bases, int bases_len);
 
 /* **** Depsgraph evaluation **** */
 
-struct Depsgraph;
-
-/* Draw Cache */
-
-enum {
-  BKE_MBALL_BATCH_DIRTY_ALL = 0,
-};
-void BKE_mball_batch_cache_dirty_tag(struct MetaBall *mb, int mode);
-void BKE_mball_batch_cache_free(struct MetaBall *mb);
-
-extern void (*BKE_mball_batch_cache_dirty_tag_cb)(struct MetaBall *mb, int mode);
-extern void (*BKE_mball_batch_cache_free_cb)(struct MetaBall *mb);
+void BKE_mball_data_update(struct Depsgraph *depsgraph, struct Scene *scene, struct Object *ob);
 
 #ifdef __cplusplus
 }