New: Option to show the paths of Bones over time.

In PoseMode, press Wkey or use the Pose pulldown menu. It calculates the
positions of all selected Bone end points, over the time as indicated with
the Scene start/end frame. This then is drawn as a path, with little black
dots on every frame, and a white dot on every 10 frames.

Paths are not saved in files, and not calculated automatic yet on changes.

To make this relative fast, but also reliable, I had to add a new method
in the Dependency graph system, to find exactly (and only) these parents
of an Object that influence its position. This is needed because the path
should show the actual global coordinates of the entire animation system.

source/blender/src/poseobject.c

@@ -184,6 +184,82 @@ int pose_channel_in_IK_chain(Object *ob, bPoseChannel *pchan)
 	return 0;
 }
 
+/* ********************************************** */
+
+/* for the object with pose/action: create path curves for selected bones */
+void pose_calculate_path(Object *ob)
+{
+	bPoseChannel *pchan;
+	Base *base;
+	float *fp;
+	int cfra;
+	
+	if(ob==NULL || ob->pose==NULL)
+		return;
+	
+	if(EFRA<=SFRA) return;
+	
+	DAG_object_update_flags(G.scene, ob, screen_view3d_layers());
+	
+	/* malloc the path blocks */
+	for(pchan= ob->pose->chanbase.first; pchan; pchan= pchan->next) {
+		if(pchan->bone && (pchan->bone->flag & BONE_SELECTED)) {
+			pchan->pathlen= EFRA-SFRA;
+			if(pchan->path)
+				MEM_freeN(pchan->path);
+			pchan->path= MEM_callocN(3*pchan->pathlen*sizeof(float), "pchan path");
+		}
+	}
+	
+	cfra= CFRA;
+	for(CFRA=SFRA; CFRA<EFRA; CFRA++) {
+		
+		/* do all updates */
+		for(base= FIRSTBASE; base; base= base->next) {
+			if(base->object->recalc) {
+				int temp= base->object->recalc;
+				object_handle_update(base->object);
+				base->object->recalc= temp;
+			}
+		}
+		
+		for(pchan= ob->pose->chanbase.first; pchan; pchan= pchan->next) {
+			if(pchan->bone && (pchan->bone->flag & BONE_SELECTED)) {
+				if(pchan->path) {
+					fp= pchan->path+3*(CFRA-SFRA);
+					VECCOPY(fp, pchan->pose_tail);
+					Mat4MulVecfl(ob->obmat, fp);
+				}
+			}
+		}
+	}
+	
+	CFRA= cfra;
+	allqueue(REDRAWVIEW3D, 0);	/* recalc tags are still there */
+}
+
+
+/* for the object with pose/action: clear all path curves */
+void pose_clear_paths(Object *ob)
+{
+	bPoseChannel *pchan;
+	
+	if(ob==NULL || ob->pose==NULL)
+		return;
+	
+	/* free the path blocks */
+	for(pchan= ob->pose->chanbase.first; pchan; pchan= pchan->next) {
+		if(pchan->path) {
+			MEM_freeN(pchan->path);
+			pchan->path= NULL;
+		}
+	}
+	
+	allqueue(REDRAWVIEW3D, 0);
+}
+
+
+
 void pose_select_constraint_target(void)
 {
 	Object *ob= OBACT;
@@ -229,13 +305,19 @@ void pose_special_editmenu(void)
 	if(!ob && !ob->pose) return;
 	if(ob==G.obedit || (ob->flag & OB_POSEMODE)==0) return;
 	
-	nr= pupmenu("Specials%t|Select Constraint Target%x1|Flip Left-Right Names%x2");
+	nr= pupmenu("Specials%t|Select Constraint Target%x1|Flip Left-Right Names%x2|Calculate Paths%x3|Clear All Paths%x4");
 	if(nr==1) {
 		pose_select_constraint_target();
 	}
 	else if(nr==2) {
 		pose_flip_names();
 	}
+	else if(nr==3) {
+		pose_calculate_path(ob);
+	}
+	else if(nr==4) {
+		pose_clear_paths(ob);
+	}
 }
 
 /* context: active object, active channel, optional selected channel */