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, 27 deletions

diff --git a/source/blender/editors/space_info/info_stats.cc b/source/blender/editors/space_info/info_stats.cc
index e41ff02254b..ee83197ec0c 100644
--- a/source/blender/editors/space_info/info_stats.cc
+++ b/source/blender/editors/space_info/info_stats.cc
@@ -168,33 +168,7 @@ static void stats_object(Object *ob,
       if ((me_eval != nullptr) && !BLI_gset_add(objects_gset, (void *)me_eval)) {
         break;
       }
-
-      if (stats_mesheval(me_eval, is_selected, stats)) {
-        break;
-      }
-      ATTR_FALLTHROUGH; /* Fall-through to displist. */
-    }
-    case OB_MBALL: {
-      int totv = 0, totf = 0, tottri = 0;
-
-      if (ob->runtime.curve_cache && ob->runtime.curve_cache->disp.first) {
-        /* NOTE: We only get the same curve_cache for instances of the same curve/font/...
-         * For simple linked duplicated objects, each has its own dispList. */
-        if (!BLI_gset_add(objects_gset, ob->runtime.curve_cache)) {
-          break;
-        }
-
-        BKE_displist_count(&ob->runtime.curve_cache->disp, &totv, &totf, &tottri);
-      }
-
-      stats->totvert += totv;
-      stats->totface += totf;
-      stats->tottri += tottri;
-
-      if (is_selected) {
-        stats->totvertsel += totv;
-        stats->totfacesel += totf;
-      }
+      stats_mesheval(me_eval, is_selected, stats);
       break;
     }
     case OB_GPENCIL: {