NLA: insert keyframes correctly for strips with non-Replace mode.

NLA strips support using the keyframe values in a variety of ways:
adding, subtracting, multiplying, linearly mixing with the result
of strips located below in the stack. This is intended for layering
tweaks on top of a base animation.

However, when inserting keyframes into such strips, it simply inserts
the final value of the property, irrespective of these settings. This
in fact makes the feature nearly useless.

To fix this it is necessary to evaluate the NLA stack below the
edited strip and correctly compute the raw key that would produce
the intended final value, according to the mode and influence.

Differential Revision: https://developer.blender.org/D3927

3 files changed, 49 insertions, 17 deletions

diff --git a/source/blender/editors/animation/anim_channels_defines.c b/source/blender/editors/animation/anim_channels_defines.c
index 9bd7e277098..341bc25875e 100644
--- a/source/blender/editors/animation/anim_channels_defines.c
+++ b/source/blender/editors/animation/anim_channels_defines.c
@@ -4125,21 +4125,25 @@ static void achannel_setting_slider_cb(bContext *C, void *id_poin, void *fcu_poi
 	ReportList *reports = CTX_wm_reports(C);
 	Scene *scene = CTX_data_scene(C);
 	ToolSettings *ts = scene->toolsettings;
+	ListBase nla_cache = {NULL, NULL};
 	PointerRNA id_ptr, ptr;
 	PropertyRNA *prop;
 	short flag = 0;
 	bool done = false;
 	float cfra;
 
+	/* Get RNA pointer */
+	RNA_id_pointer_create(id, &id_ptr);
+
+	/* Get NLA context for value remapping */
+	NlaKeyframingContext *nla_context = BKE_animsys_get_nla_keyframing_context(&nla_cache, depsgraph, &id_ptr, adt, (float)CFRA);
+
 	/* get current frame and apply NLA-mapping to it (if applicable) */
 	cfra = BKE_nla_tweakedit_remap(adt, (float)CFRA, NLATIME_CONVERT_UNMAP);
 
 	/* get flags for keyframing */
 	flag = ANIM_get_keyframing_flags(scene, 1);
 
-	/* get RNA pointer, and resolve the path */
-	RNA_id_pointer_create(id, &id_ptr);
-
 	/* try to resolve the path stored in the F-Curve */
 	if (RNA_path_resolve_property(&id_ptr, fcu->rna_path, &ptr, &prop)) {
 		/* set the special 'replace' flag if on a keyframe */
@@ -4147,11 +4151,13 @@ static void achannel_setting_slider_cb(bContext *C, void *id_poin, void *fcu_poi
 			flag |= INSERTKEY_REPLACE;
 
 		/* insert a keyframe for this F-Curve */
-		done = insert_keyframe_direct(depsgraph, reports, ptr, prop, fcu, cfra, ts->keyframe_type, flag);
+		done = insert_keyframe_direct(depsgraph, reports, ptr, prop, fcu, cfra, ts->keyframe_type, nla_context, flag);
 
 		if (done)
 			WM_event_add_notifier(C, NC_ANIMATION | ND_ANIMCHAN | NA_EDITED, NULL);
 	}
+
+	BKE_animsys_free_nla_keyframing_context_cache(&nla_cache);
 }
 
 /* callback for shapekey widget sliders - insert keyframes */
@@ -4166,21 +4172,25 @@ static void achannel_setting_slider_shapekey_cb(bContext *C, void *key_poin, voi
 	ReportList *reports = CTX_wm_reports(C);
 	Scene *scene = CTX_data_scene(C);
 	ToolSettings *ts = scene->toolsettings;
+	ListBase nla_cache = {NULL, NULL};
 	PointerRNA id_ptr, ptr;
 	PropertyRNA *prop;
 	short flag = 0;
 	bool done = false;
 	float cfra;
 
+	/* Get RNA pointer */
+	RNA_id_pointer_create((ID *)key, &id_ptr);
+
+	/* Get NLA context for value remapping */
+	NlaKeyframingContext *nla_context = BKE_animsys_get_nla_keyframing_context(&nla_cache, depsgraph, &id_ptr, key->adt, (float)CFRA);
+
 	/* get current frame and apply NLA-mapping to it (if applicable) */
 	cfra = BKE_nla_tweakedit_remap(key->adt, (float)CFRA, NLATIME_CONVERT_UNMAP);
 
 	/* get flags for keyframing */
 	flag = ANIM_get_keyframing_flags(scene, 1);
 
-	/* get RNA pointer, and resolve the path */
-	RNA_id_pointer_create((ID *)key, &id_ptr);
-
 	/* try to resolve the path stored in the F-Curve */
 	if (RNA_path_resolve_property(&id_ptr, rna_path, &ptr, &prop)) {
 		/* find or create new F-Curve */
@@ -4193,7 +4203,7 @@ static void achannel_setting_slider_shapekey_cb(bContext *C, void *key_poin, voi
 			flag |= INSERTKEY_REPLACE;
 
 		/* insert a keyframe for this F-Curve */
-		done = insert_keyframe_direct(depsgraph, reports, ptr, prop, fcu, cfra, ts->keyframe_type, flag);
+		done = insert_keyframe_direct(depsgraph, reports, ptr, prop, fcu, cfra, ts->keyframe_type, nla_context, flag);
 
 		if (done)
 			WM_event_add_notifier(C, NC_ANIMATION | ND_ANIMCHAN | NA_EDITED, NULL);
@@ -4202,6 +4212,8 @@ static void achannel_setting_slider_shapekey_cb(bContext *C, void *key_poin, voi
 	/* free the path */
 	if (rna_path)
 		MEM_freeN(rna_path);
+
+	BKE_animsys_free_nla_keyframing_context_cache(&nla_cache);
 }
 
 /* callback for NLA Control Curve widget sliders - insert keyframes */
@@ -4237,7 +4249,7 @@ static void achannel_setting_slider_nla_curve_cb(bContext *C, void *UNUSED(id_po
 			flag |= INSERTKEY_REPLACE;
 
 		/* insert a keyframe for this F-Curve */
-		done = insert_keyframe_direct(depsgraph, reports, ptr, prop, fcu, cfra, ts->keyframe_type, flag);
+		done = insert_keyframe_direct(depsgraph, reports, ptr, prop, fcu, cfra, ts->keyframe_type, NULL, flag);
 
 		if (done)
 			WM_event_add_notifier(C, NC_ANIMATION | ND_ANIMCHAN | NA_EDITED, NULL);
diff --git a/source/blender/editors/animation/keyframing.c b/source/blender/editors/animation/keyframing.c
index 77dcc17c42a..b93c2ae5c7b 100644
--- a/source/blender/editors/animation/keyframing.c
+++ b/source/blender/editors/animation/keyframing.c
@@ -965,7 +965,7 @@ static float visualkey_get_value(Depsgraph *depsgraph, PointerRNA *ptr, Property
  * the keyframe insertion. These include the 'visual' keyframing modes, quick refresh,
  * and extra keyframe filtering.
  */
-bool insert_keyframe_direct(Depsgraph *depsgraph, ReportList *reports, PointerRNA ptr, PropertyRNA *prop, FCurve *fcu, float cfra, eBezTriple_KeyframeType keytype, eInsertKeyFlags flag)
+bool insert_keyframe_direct(Depsgraph *depsgraph, ReportList *reports, PointerRNA ptr, PropertyRNA *prop, FCurve *fcu, float cfra, eBezTriple_KeyframeType keytype, struct NlaKeyframingContext *nla_context, eInsertKeyFlags flag)
 {
 	float curval = 0.0f;
 
@@ -1038,6 +1038,12 @@ bool insert_keyframe_direct(Depsgraph *depsgraph, ReportList *reports, PointerRN
 		curval = setting_get_rna_value(depsgraph, &ptr, prop, fcu->array_index, false);
 	}
 
+	/* adjust the value for NLA factors */
+	if (!BKE_animsys_nla_remap_keyframe_value(nla_context, &ptr, prop, fcu->array_index, &curval)) {
+		BKE_report(reports, RPT_ERROR, "Could not insert keyframe due to zero NLA influence or base value");
+		return false;
+	}
+
 	/* adjust coordinates for cycle aware insertion */
 	if (flag & INSERTKEY_CYCLE_AWARE) {
 		if (remap_cyclic_keyframe_location(fcu, &cfra, &curval) != FCU_CYCLE_PERFECT) {
@@ -1094,12 +1100,14 @@ bool insert_keyframe_direct(Depsgraph *depsgraph, ReportList *reports, PointerRN
  */
 short insert_keyframe(
         Main *bmain, Depsgraph *depsgraph, ReportList *reports, ID *id, bAction *act,
-        const char group[], const char rna_path[], int array_index, float cfra, eBezTriple_KeyframeType keytype, eInsertKeyFlags flag)
+        const char group[], const char rna_path[], int array_index, float cfra, eBezTriple_KeyframeType keytype, ListBase *nla_cache, eInsertKeyFlags flag)
 {
 	PointerRNA id_ptr, ptr;
 	PropertyRNA *prop = NULL;
 	AnimData *adt;
 	FCurve *fcu;
+	ListBase tmp_nla_cache = {NULL, NULL};
+	NlaKeyframingContext *nla_context = NULL;
 	int array_index_max = array_index + 1;
 	int ret = 0;
 
@@ -1132,7 +1140,14 @@ short insert_keyframe(
 
 	/* apply NLA-mapping to frame to use (if applicable) */
 	adt = BKE_animdata_from_id(id);
-	cfra = BKE_nla_tweakedit_remap(adt, cfra, NLATIME_CONVERT_UNMAP);
+
+	if (adt && adt->action == act) {
+		/* Get NLA context for value remapping. */
+		nla_context = BKE_animsys_get_nla_keyframing_context(nla_cache ? nla_cache : &tmp_nla_cache, depsgraph, &id_ptr, adt, cfra);
+
+		/* Apply NLA-mapping to frame. */
+		cfra = BKE_nla_tweakedit_remap(adt, cfra, NLATIME_CONVERT_UNMAP);
+	}
 
 	/* key entire array convenience method */
 	if (array_index == -1) {
@@ -1172,10 +1187,12 @@ short insert_keyframe(
 			}
 
 			/* insert keyframe */
-			ret += insert_keyframe_direct(depsgraph, reports, ptr, prop, fcu, cfra, keytype, flag);
+			ret += insert_keyframe_direct(depsgraph, reports, ptr, prop, fcu, cfra, keytype, nla_context, flag);
 		}
 	}
 
+	BKE_animsys_free_nla_keyframing_context_cache(&tmp_nla_cache);
+
 	if (ret) {
 		if (act != NULL) {
 			DEG_id_tag_update(&act->id, ID_RECALC_COPY_ON_WRITE);
@@ -1904,7 +1921,7 @@ static int insert_key_button_exec(bContext *C, wmOperator *op)
 			FCurve *fcu = list_find_fcurve(&strip->fcurves, RNA_property_identifier(prop), index);
 
 			if (fcu) {
-				success = insert_keyframe_direct(depsgraph, op->reports, ptr, prop, fcu, cfra, ts->keyframe_type, 0);
+				success = insert_keyframe_direct(depsgraph, op->reports, ptr, prop, fcu, cfra, ts->keyframe_type, NULL, 0);
 			}
 			else {
 				BKE_report(op->reports, RPT_ERROR,
@@ -1919,7 +1936,7 @@ static int insert_key_button_exec(bContext *C, wmOperator *op)
 			fcu = rna_get_fcurve_context_ui(C, &ptr, prop, index, NULL, NULL, &driven, &special);
 
 			if (fcu && driven) {
-				success = insert_keyframe_direct(depsgraph, op->reports, ptr, prop, fcu, cfra, ts->keyframe_type, INSERTKEY_DRIVER);
+				success = insert_keyframe_direct(depsgraph, op->reports, ptr, prop, fcu, cfra, ts->keyframe_type, NULL, INSERTKEY_DRIVER);
 			}
 		}
 		else {
@@ -1955,7 +1972,7 @@ static int insert_key_button_exec(bContext *C, wmOperator *op)
 					index = -1;
 				}
 
-				success = insert_keyframe(bmain, depsgraph, op->reports, ptr.id.data, NULL, group, path, index, cfra, ts->keyframe_type, flag);
+				success = insert_keyframe(bmain, depsgraph, op->reports, ptr.id.data, NULL, group, path, index, cfra, ts->keyframe_type, NULL, flag);
 
 				MEM_freeN(path);
 			}
diff --git a/source/blender/editors/animation/keyingsets.c b/source/blender/editors/animation/keyingsets.c
index 1fe8a34d166..d980e4322dd 100644
--- a/source/blender/editors/animation/keyingsets.c
+++ b/source/blender/editors/animation/keyingsets.c
@@ -962,6 +962,7 @@ int ANIM_apply_keyingset(bContext *C, ListBase *dsources, bAction *act, KeyingSe
 	Scene *scene = CTX_data_scene(C);
 	ReportList *reports = CTX_wm_reports(C);
 	KS_Path *ksp;
+	ListBase nla_cache = {NULL, NULL};
 	const short base_kflags = ANIM_get_keyframing_flags(scene, 1);
 	const char *groupname = NULL;
 	short kflag = 0, success = 0;
@@ -1039,7 +1040,7 @@ int ANIM_apply_keyingset(bContext *C, ListBase *dsources, bAction *act, KeyingSe
 		for (; i < arraylen; i++) {
 			/* action to take depends on mode */
 			if (mode == MODIFYKEY_MODE_INSERT)
-				success += insert_keyframe(bmain, depsgraph, reports, ksp->id, act, groupname, ksp->rna_path, i, cfra, keytype, kflag2);
+				success += insert_keyframe(bmain, depsgraph, reports, ksp->id, act, groupname, ksp->rna_path, i, cfra, keytype, &nla_cache, kflag2);
 			else if (mode == MODIFYKEY_MODE_DELETE)
 				success += delete_keyframe(bmain, reports, ksp->id, act, groupname, ksp->rna_path, i, cfra, kflag2);
 		}
@@ -1063,6 +1064,8 @@ int ANIM_apply_keyingset(bContext *C, ListBase *dsources, bAction *act, KeyingSe
 		WM_main_add_notifier(NC_ANIMATION | ND_KEYFRAME | NA_ADDED, NULL);
 	}
 
+	BKE_animsys_free_nla_keyframing_context_cache(&nla_cache);
+
 	/* return the number of channels successfully affected */
 	return success;
 }