Eevee: LightCache: Initial Implementation

This separate probe rendering from viewport rendering, making possible to
run the baking in another thread (non blocking and faster).

The baked lighting is saved in the blend file. Nothing needs to be
recomputed on load.

There is a few missing bits / bugs:
- Cache cannot be saved to disk as a separate file, it is saved in the DNA
  for now making file larger and memory usage higher.
- Auto update only cubemaps does update the grids (bug).
- Probes cannot be updated individually (considered as dynamic).
- Light Cache cannot be (re)generated during render.

1 files changed, 18 insertions, 0 deletions

diff --git a/source/blender/depsgraph/intern/eval/deg_eval_copy_on_write.cc b/source/blender/depsgraph/intern/eval/deg_eval_copy_on_write.cc
index 794cc22f4e3..20aec0ba5ed 100644
--- a/source/blender/depsgraph/intern/eval/deg_eval_copy_on_write.cc
+++ b/source/blender/depsgraph/intern/eval/deg_eval_copy_on_write.cc
@@ -555,6 +555,13 @@ void update_special_pointers(const Depsgraph *depsgraph,
 			update_particle_system_orig_pointers(object_orig, object_cow);
 			break;
 		}
+		case ID_SCE:
+		{
+			Scene *scene_cow = (Scene *)id_cow;
+			const Scene *scene_orig = (const Scene *)id_orig;
+			scene_cow->eevee.light_cache = scene_orig->eevee.light_cache;
+			break;
+		}
 		default:
 			break;
 	}
@@ -926,6 +933,12 @@ void discard_mesh_edit_mode_pointers(ID *id_cow)
 	mesh_cow->edit_btmesh = NULL;
 }
 
+void discard_scene_pointers(ID *id_cow)
+{
+	Scene *scene_cow = (Scene *)id_cow;
+	scene_cow->eevee.light_cache = NULL;
+}
+
 /* NULL-ify all edit mode pointers which points to data from
  * original object.
  */
@@ -948,6 +961,11 @@ void discard_edit_mode_pointers(ID *id_cow)
 		case ID_LT:
 			discard_lattice_edit_mode_pointers(id_cow);
 			break;
+		case ID_SCE:
+			/* Not really edit mode but still needs to run before
+			 * BKE_libblock_free_datablock() */
+			discard_scene_pointers(id_cow);
+			break;
 		default:
 			break;
 	}