Bendy Bones: Advanced B-Bones for Easier + Simple Rigging

This commit/patch/branch brings a bunch of powerful new options for B-Bones and
for working with B-Bones, making it easier for animators to create their own
rigs, using fewer bones (which also means hopefully lighter + faster rigs ;)
This functionality was first demoed by Daniel at BConf15

Some highlights from this patch include:
* You can now directly control the shape of B-Bones using a series of properties
  instead of being restricted to trying to indirectly control them through the
  neighbouring bones.  See the "Bendy Bones" panel...

* B-Bones can be shaped in EditMode to define a "curved rest pose" for the bone.
  This is useful for things like eyebrows and mouths/eyelids

* You can now make B-Bones use custom bones as their reference bone handles,
  instead of only using the parent/child bones. To do so, enable the
  "Use Custom Reference Handles" toggle. If none are specified, then the BBone will
  only use the Bendy Bone properties.

* Constraints Head/Tail option can now slide along the B-Bone shape, instead of
  just linearly interpolating between the endpoints of the bone.

For more details, see:
* http://aligorith.blogspot.co.nz/2016/05/bendy-bones-dev-update.html
* http://aligorith.blogspot.co.nz/2016/05/an-in-depth-look-at-how-b-bones-work.html



-- Credits --
Original Idea: Daniel M Lara (pepeland)
Original Patch/Research: Jose Molina
Additional Development + Polish: Joshua Leung (aligorith)
Testing/Feedback: Daniel M Lara (pepeland), Juan Pablo Bouza (jpbouza)

1 files changed, 78 insertions, 0 deletions

diff --git a/source/blender/makesrna/intern/rna_armature.c b/source/blender/makesrna/intern/rna_armature.c
index a8ef4664fd7..842e220e8b5 100644
--- a/source/blender/makesrna/intern/rna_armature.c
+++ b/source/blender/makesrna/intern/rna_armature.c
@@ -482,6 +482,82 @@ static void rna_Armature_transform(struct bArmature *arm, float *mat)
 
 #else
 
+/* Settings for curved bbone settings - The posemode values get applied over the top of the editmode ones */
+void rna_def_bone_curved_common(StructRNA *srna, bool is_posebone)
+{
+#define RNA_DEF_CURVEBONE_UPDATE(prop, is_posebone)                                \
+	{                                                                              \
+		if (is_posebone)                                                           \
+			RNA_def_property_update(prop, NC_OBJECT | ND_POSE, "rna_Pose_update"); \
+		else                                                                       \
+			RNA_def_property_update(prop, 0, "rna_Armature_update_data");          \
+	} (void)0;
+	
+	PropertyRNA *prop;
+	
+	/* Roll In/Out */
+	prop = RNA_def_property(srna, "bbone_rollin", PROP_FLOAT, PROP_ANGLE);
+	RNA_def_property_float_sdna(prop, NULL, "roll1");
+	RNA_def_property_range(prop, -M_PI * 2.0f, M_PI * 2.0f);
+	RNA_def_property_ui_text(prop, "Roll In", "Roll offset for the start of the B-Bone, adjusts twist");
+	RNA_DEF_CURVEBONE_UPDATE(prop, is_posebone);
+	
+	prop = RNA_def_property(srna, "bbone_rollout", PROP_FLOAT, PROP_ANGLE);
+	RNA_def_property_float_sdna(prop, NULL, "roll2");
+	RNA_def_property_range(prop, -M_PI * 2.0f, M_PI * 2.0f);
+	RNA_def_property_ui_text(prop, "Roll Out", "Roll offset for the end of the B-Bone, adjusts twist");
+	RNA_DEF_CURVEBONE_UPDATE(prop, is_posebone);
+	
+	if (is_posebone == false) {
+		prop = RNA_def_property(srna, "use_endroll_as_inroll", PROP_BOOLEAN, PROP_NONE);
+		RNA_def_property_ui_text(prop, "Inherit End Roll", "Use Roll Out of parent bone as Roll In of its children");
+		RNA_def_property_boolean_sdna(prop, NULL, "flag", BONE_ADD_PARENT_END_ROLL);
+		RNA_def_property_update(prop, 0, "rna_Armature_update_data");
+	}
+	
+	/* Curve X/Y Offsets */
+	prop = RNA_def_property(srna, "bbone_curveinx", PROP_FLOAT, PROP_NONE);
+	RNA_def_property_float_sdna(prop, NULL, "curveInX");
+	RNA_def_property_range(prop, -5.0f, 5.0f);
+	RNA_def_property_ui_text(prop, "In X", "X-axis handle offset for start of the B-Bone's curve, adjusts curvature");
+	RNA_DEF_CURVEBONE_UPDATE(prop, is_posebone);
+	
+	prop = RNA_def_property(srna, "bbone_curveiny", PROP_FLOAT, PROP_NONE);
+	RNA_def_property_float_sdna(prop, NULL, "curveInY");
+	RNA_def_property_range(prop, -5.0f, 5.0f);
+	RNA_def_property_ui_text(prop, "In Y", "Y-axis handle offset for start of the B-Bone's curve, adjusts curvature");
+	RNA_DEF_CURVEBONE_UPDATE(prop, is_posebone);
+	
+	prop = RNA_def_property(srna, "bbone_curveoutx", PROP_FLOAT, PROP_NONE);
+	RNA_def_property_float_sdna(prop, NULL, "curveOutX");
+	RNA_def_property_range(prop, -5.0f, 5.0f);
+	RNA_def_property_ui_text(prop, "Out X", "X-axis handle offset for end of the B-Bone's curve, adjusts curvature");
+	RNA_DEF_CURVEBONE_UPDATE(prop, is_posebone);
+	
+	prop = RNA_def_property(srna, "bbone_curveouty", PROP_FLOAT, PROP_NONE);
+	RNA_def_property_float_sdna(prop, NULL, "curveOutY");
+	RNA_def_property_range(prop, -5.0f, 5.0f);
+	RNA_def_property_ui_text(prop, "Out Y", "Y-axis handle offset for end of the B-Bone's curve, adjusts curvature");
+	RNA_DEF_CURVEBONE_UPDATE(prop, is_posebone);
+	
+	/* Scale In/Out */
+	prop = RNA_def_property(srna, "bbone_scalein", PROP_FLOAT, PROP_NONE);
+	RNA_def_property_float_sdna(prop, NULL, "scaleIn");
+	RNA_def_property_range(prop, 0.0f, 5.0f);
+	RNA_def_property_float_default(prop, 1.0f);
+	RNA_def_property_ui_text(prop, "Scale In", "Scale factor for start of the B-Bone, adjusts thickness (for tapering effects)");
+	RNA_DEF_CURVEBONE_UPDATE(prop, is_posebone);
+	
+	prop = RNA_def_property(srna, "bbone_scaleout", PROP_FLOAT, PROP_NONE);
+	RNA_def_property_float_sdna(prop, NULL, "scaleOut");
+	RNA_def_property_range(prop, 0.0f, 5.0f);
+	RNA_def_property_float_default(prop, 1.0f);
+	RNA_def_property_ui_text(prop, "Scale Out", "Scale factor for end of the B-Bone, adjusts thickness (for tapering effects)");
+	RNA_DEF_CURVEBONE_UPDATE(prop, is_posebone);
+	
+#undef RNA_DEF_CURVEBONE_UPDATE
+}
+
 static void rna_def_bone_common(StructRNA *srna, int editbone)
 {
 	PropertyRNA *prop;
@@ -653,6 +729,7 @@ static void rna_def_bone(BlenderRNA *brna)
 	RNA_def_property_ui_text(prop, "Children", "Bones which are children of this bone");
 
 	rna_def_bone_common(srna, 0);
+	rna_def_bone_curved_common(srna, 0);
 
 	/* XXX should we define this in PoseChannel wrapping code instead?
 	 *     But PoseChannels directly get some of their flags from here... */
@@ -766,6 +843,7 @@ static void rna_def_edit_bone(BlenderRNA *brna)
 	RNA_def_property_update(prop, 0, "rna_Armature_editbone_transform_update");
 
 	rna_def_bone_common(srna, 1);
+	rna_def_bone_curved_common(srna, 0);
 
 	prop = RNA_def_property(srna, "hide", PROP_BOOLEAN, PROP_NONE);
 	RNA_def_property_boolean_sdna(prop, NULL, "flag", BONE_HIDDEN_A);