Objects: restore H key per object hiding.

H hides selected objects, Shift+H hides unselected objects, and Alt+H
reveals hidden objects.

This hiding state is distinct from restrict viewport and render, and
meant for temporarily hiding objects without affecting more persistent
collection hiding.

Object hiding is per view-layer, same as selection. It affects the
viewport and any preview renders in there, but not final renders.

In the outliner, different icons are now used for temporary hiding, and
restrict viewport and render. Hidden objects are greyed out.

Remaining design issues:

* For lamps we probably still want to keep their effect on the scene,
  currently they are fully disabled by hiding. Arguably mesh lights or
  even objects being reflected or casting shadows are not that different
  but perhaps the special lamp exception from local view should remain.
* We need a feature still to disabled this hiding for specific viewports,
  for render or animation preview where you want to see the entire scene
  while working in another view.
* We need a new icon for restrict viewport, for now it uses a grid similar
  to the 2.4 icon.
* Hiding objects does not preserve selection state as it did in 2.7,
  it's probably convenient to support this again?

1 files changed, 16 insertions, 2 deletions

diff --git a/source/blender/makesdna/DNA_layer_types.h b/source/blender/makesdna/DNA_layer_types.h
index 44bf5be2407..f7536ec0df5 100644
--- a/source/blender/makesdna/DNA_layer_types.h
+++ b/source/blender/makesdna/DNA_layer_types.h
@@ -56,7 +56,8 @@ typedef struct LayerCollection {
 	struct Collection *collection;
 	struct SceneCollection *scene_collection DNA_DEPRECATED;
 	short flag;
-	short pad[3];
+	short runtime_flag;
+	short pad[2];
 	ListBase layer_collections; /* synced with collection->children */
 } LayerCollection;
 
@@ -64,7 +65,8 @@ typedef struct ViewLayer {
 	struct ViewLayer *next, *prev;
 	char name[64]; /* MAX_NAME */
 	short flag;
-	short pad[3];
+	short runtime_flag;
+	short pad[2];
 	ListBase object_bases;      /* ObjectBase */
 	struct SceneStats *stats;   /* default allocated now */
 	struct Base *basact;
@@ -97,6 +99,7 @@ enum {
 	BASE_FROM_SET         = (1 << 5), /* To be set only by the depsgraph */
 	BASE_VISIBLE_VIEWPORT = (1 << 6),
 	BASE_VISIBLE_RENDER   = (1 << 7),
+	BASE_HIDE             = (1 << 8),
 };
 
 /* LayerCollection->flag */
@@ -108,6 +111,12 @@ enum {
 	LAYER_COLLECTION_EXCLUDE = (1 << 4),
 };
 
+/* Layer Collection->runtime_flag */
+enum {
+	LAYER_COLLECTION_HAS_VISIBLE_OBJECTS = (1 << 0),
+	LAYER_COLLECTION_HAS_SELECTED_OBJECTS = (1 << 1),
+};
+
 /* ViewLayer->flag */
 enum {
 	VIEW_LAYER_RENDER = (1 << 0),
@@ -115,6 +124,11 @@ enum {
 	VIEW_LAYER_FREESTYLE = (1 << 2),
 };
 
+/* ViewLayer->runtime_flag */
+enum {
+	VIEW_LAYER_HAS_HIDE = (1 << 0),
+};
+
 /****************************** Deprecated ******************************/
 
 /* Compatibility with collections saved in early 2.8 versions,