BGE: TrackTo actuator: increasing up & track axis options

This is related to Task T34861 to increase up & track axis options for TrackTo actuator. I've just added it to differential to facilitate an easier review.

With the patch applied you can select X, Y and Z axis for the Up axis, and X, Y, Z, -X, -Y and -Z for the track axis.

Related to the implementation I have used the algorithm from Trackto constrain placed in constrain.c but adapted to be used with MOTO library.

The wiki docs are here (http://wiki.blender.org/index.php/User:Lordloki/Doc:2.6/Manual/Game_Engine/Logic/Actuators/Edit_Object#Trackto_Actuator).

Test file is here: {F97623}

I have also uploaded 2 screenshots showing the UI modifications to the TrackTo actuator:

{F91992} {F91990}

Reviewers: moguri, dfelinto

Reviewed By: moguri

CC: Genome36

Differential Revision: https://developer.blender.org/D565

16 files changed, 249 insertions, 149 deletions

diff --git a/doc/python_api/rst/bge.logic.rst b/doc/python_api/rst/bge.logic.rst
index 4e0d317e4bf..d901a4e4207 100644
--- a/doc/python_api/rst/bge.logic.rst
+++ b/doc/python_api/rst/bge.logic.rst
@@ -868,6 +868,23 @@ See :class:`bge.types.KX_SteeringActuator.behavior`
 
    :value: 3
 
+.. _logic-trackto-actuator:
+
+-----------------
+TrackTo Actuator
+-----------------
+
+See :class:`bge.types.KX_TrackToActuator`
+
+.. data:: KX_TRACK_UPAXIS_POS_X
+.. data:: KX_TRACK_UPAXIS_POS_Y
+.. data:: KX_TRACK_UPAXIS_POS_Z
+.. data:: KX_TRACK_TRAXIS_POS_X
+.. data:: KX_TRACK_TRAXIS_POS_Y
+.. data:: KX_TRACK_TRAXIS_POS_Z
+.. data:: KX_TRACK_TRAXIS_NEG_X
+.. data:: KX_TRACK_TRAXIS_NEG_Y
+.. data:: KX_TRACK_TRAXIS_NEG_Z
 
 =======
 Various
diff --git a/doc/python_api/rst/bge_types/bge.types.KX_TrackToActuator.rst b/doc/python_api/rst/bge_types/bge.types.KX_TrackToActuator.rst
index 070243c6a05..5b5c5d0c0db 100644
--- a/doc/python_api/rst/bge_types/bge.types.KX_TrackToActuator.rst
+++ b/doc/python_api/rst/bge_types/bge.types.KX_TrackToActuator.rst
@@ -37,3 +37,25 @@ base class --- :class:`SCA_IActuator`
 
       :type: boolean
 
+   .. attribute:: upAxis
+
+      The axis that points upward.
+
+      :type: integer from 0 to 2
+
+      * KX_TRACK_UPAXIS_POS_X
+      * KX_TRACK_UPAXIS_POS_Y
+      * KX_TRACK_UPAXIS_POS_Z
+
+   .. attribute:: trackAxis
+
+      The axis that points to the target object.
+
+      :type: integer from 0 to 5
+
+      * KX_TRACK_TRAXIS_POS_X
+      * KX_TRACK_TRAXIS_POS_Y
+      * KX_TRACK_TRAXIS_POS_Z
+      * KX_TRACK_TRAXIS_NEG_X
+      * KX_TRACK_TRAXIS_NEG_Y
+      * KX_TRACK_TRAXIS_NEG_Z
diff --git a/intern/moto/include/MT_Matrix3x3.h b/intern/moto/include/MT_Matrix3x3.h
index 6d709fae662..17dd5335217 100644
--- a/intern/moto/include/MT_Matrix3x3.h
+++ b/intern/moto/include/MT_Matrix3x3.h
@@ -84,11 +84,18 @@ public:
 	MT_Vector3 getColumn(int i) const {
 		return MT_Vector3(m_el[0][i], m_el[1][i], m_el[2][i]);
 	}
+
 	void setColumn(int i, const MT_Vector3& v) {
 		m_el[0][i] = v[0];
 		m_el[1][i] = v[1];
 		m_el[2][i] = v[2];
 	}
+
+	void setRow(int i, const MT_Vector3& v) {
+		m_el[i][0] = v[0];
+		m_el[i][1] = v[1];
+		m_el[i][2] = v[2];
+	}
     
     void setValue(const float *m) {
         m_el[0][0] = *m++; m_el[1][0] = *m++; m_el[2][0] = *m++; m++;
diff --git a/intern/moto/include/MT_Vector3.h b/intern/moto/include/MT_Vector3.h
index 83c53a19d66..b06f345bdaf 100644
--- a/intern/moto/include/MT_Vector3.h
+++ b/intern/moto/include/MT_Vector3.h
@@ -75,7 +75,7 @@ public:
     void        normalize();
     MT_Vector3  normalized() const;
 	MT_Vector3  safe_normalized() const;
-	
+	MT_Vector3  safe_normalized_vec(MT_Vector3 vecnormalized) const;
 
     void        scale(MT_Scalar x, MT_Scalar y, MT_Scalar z); 
     MT_Vector3  scaled(MT_Scalar x, MT_Scalar y, MT_Scalar z) const; 
diff --git a/intern/moto/include/MT_Vector3.inl b/intern/moto/include/MT_Vector3.inl
index b17ef47c709..09c92c6ab54 100644
--- a/intern/moto/include/MT_Vector3.inl
+++ b/intern/moto/include/MT_Vector3.inl
@@ -77,6 +77,13 @@ GEN_INLINE MT_Vector3 MT_Vector3::safe_normalized() const {
         *this / len; 
 }
 
+GEN_INLINE MT_Vector3 MT_Vector3::safe_normalized_vec(MT_Vector3 vecnormalized) const {
+	MT_Scalar len = length();
+	return MT_fuzzyZero(len) ?
+        vecnormalized :
+        *this / len;
+}
+
 GEN_INLINE void MT_Vector3::scale(MT_Scalar xx, MT_Scalar yy, MT_Scalar zz) {
     m_co[0] *= xx; m_co[1] *= yy; m_co[2] *= zz;
 }
diff --git a/release/scripts/startup/bl_ui/properties_object.py b/release/scripts/startup/bl_ui/properties_object.py
index 6b7e7b47281..9d958892c73 100644
--- a/release/scripts/startup/bl_ui/properties_object.py
+++ b/release/scripts/startup/bl_ui/properties_object.py
@@ -301,10 +301,11 @@ class OBJECT_PT_relations_extras(ObjectButtonsPanel, Panel):
 
         split = layout.split()
 
-        col = split.column()
-        col.label(text="Tracking Axes:")
-        col.prop(ob, "track_axis", text="Axis")
-        col.prop(ob, "up_axis", text="Up Axis")
+        if context.scene.render.engine != 'BLENDER_GAME':
+            col = split.column()
+            col.label(text="Tracking Axes:")
+            col.prop(ob, "track_axis", text="Axis")
+            col.prop(ob, "up_axis", text="Up Axis")
 
         col = split.column()
         col.prop(ob, "use_slow_parent")
diff --git a/source/blender/blenkernel/BKE_blender.h b/source/blender/blenkernel/BKE_blender.h
index 0af45a147a4..19fa60f5827 100644
--- a/source/blender/blenkernel/BKE_blender.h
+++ b/source/blender/blenkernel/BKE_blender.h
@@ -42,7 +42,7 @@ extern "C" {
  * and keep comment above the defines.
  * Use STRINGIFY() rather than defining with quotes */
 #define BLENDER_VERSION         271
-#define BLENDER_SUBVERSION      1
+#define BLENDER_SUBVERSION      2
 /* 262 was the last editmesh release but it has compatibility code for bmesh data */
 #define BLENDER_MINVERSION      270
 #define BLENDER_MINSUBVERSION   5
diff --git a/source/blender/blenkernel/intern/sca.c b/source/blender/blenkernel/intern/sca.c
index 1310162483e..4be75344133 100644
--- a/source/blender/blenkernel/intern/sca.c
+++ b/source/blender/blenkernel/intern/sca.c
@@ -392,6 +392,7 @@ void init_actuator(bActuator *act)
 	bSteeringActuator *sta;
 	bArmatureActuator *arma;
 	bMouseActuator *ma;
+	bEditObjectActuator *eoa;
 	
 	if (act->data) MEM_freeN(act->data);
 	act->data= NULL;
@@ -430,6 +431,9 @@ void init_actuator(bActuator *act)
 		break;
 	case ACT_EDIT_OBJECT:
 		act->data= MEM_callocN(sizeof(bEditObjectActuator), "editobact");
+		eoa = act->data;
+		eoa->upflag= ACT_TRACK_UP_Z;
+		eoa->trackflag= ACT_TRACK_TRAXIS_Y;
 		break;
 	case ACT_CONSTRAINT:
 		act->data= MEM_callocN(sizeof(bConstraintActuator), "cons act");
diff --git a/source/blender/blenloader/intern/versioning_270.c b/source/blender/blenloader/intern/versioning_270.c
index 103f9b76ba7..dde16c8d44f 100644
--- a/source/blender/blenloader/intern/versioning_270.c
+++ b/source/blender/blenloader/intern/versioning_270.c
@@ -42,6 +42,7 @@
 #include "DNA_mesh_types.h"
 #include "DNA_modifier_types.h"
 #include "DNA_linestyle_types.h"
+#include "DNA_actuator_types.h"
 
 #include "DNA_genfile.h"
 
@@ -310,6 +311,29 @@ void blo_do_versions_270(FileData *fd, Library *UNUSED(lib), Main *main)
 		}
 	}
 
+	if (!MAIN_VERSION_ATLEAST(main, 271, 2)) {
+		/* init up & track axis property of trackto actuators */
+		Object *ob;
+
+		for (ob = main->object.first; ob; ob = ob->id.next) {
+			bActuator *act;
+			for (act = ob->actuators.first; act; act = act->next) {
+				if (act->type == ACT_EDIT_OBJECT) {
+					bEditObjectActuator *eoact = act->data;
+					eoact->trackflag = ob->trackflag;
+					/* if trackflag is pointing +-Z axis then upflag should point Y axis.
+					 * Rest of trackflag cases, upflag should be point z axis */
+					if ((ob->trackflag == OB_POSZ) || (ob->trackflag == OB_NEGZ)) {
+						eoact->upflag = 1;
+					}
+					else {
+						eoact->upflag = 2;
+					}
+				}
+			}
+		}
+	}
+
 	if (!DNA_struct_elem_find(fd->filesdna, "RenderData", "int", "preview_start_resolution")) {
 		Scene *scene;
 		for (scene = main->scene.first; scene; scene = scene->id.next) {
diff --git a/source/blender/editors/space_logic/logic_window.c b/source/blender/editors/space_logic/logic_window.c
index b52d6265800..c3a3dda2c47 100644
--- a/source/blender/editors/space_logic/logic_window.c
+++ b/source/blender/editors/space_logic/logic_window.c
@@ -1720,6 +1720,12 @@ static void draw_actuator_edit_object(uiLayout *layout, PointerRNA *ptr)
 			sub = uiLayoutSplit(split, 0.7f, false);
 			uiItemR(sub, ptr, "time", 0, NULL, ICON_NONE);
 			uiItemR(sub, ptr, "use_3d_tracking", UI_ITEM_R_TOGGLE, NULL, ICON_NONE);
+
+			row = uiLayoutRow(layout, false);
+			uiItemR(row, ptr, "up_axis", 0, NULL, ICON_NONE);
+
+			row = uiLayoutRow(layout, false);
+			uiItemR(row, ptr, "track_axis", 0, NULL, ICON_NONE);
 			break;
 		case ACT_EDOB_DYNAMICS:
 			if (ob->type != OB_MESH) {
diff --git a/source/blender/makesdna/DNA_actuator_types.h b/source/blender/makesdna/DNA_actuator_types.h
index 5ab799a75e5..7698d671117 100644
--- a/source/blender/makesdna/DNA_actuator_types.h
+++ b/source/blender/makesdna/DNA_actuator_types.h
@@ -97,6 +97,8 @@ typedef struct bEditObjectActuator {
 	float mass;
 	short localflag; /* flag for the lin & ang. vel: apply locally   */
 	short dyn_operation;
+	short upflag, trackflag; /* flag for up axis and track axis */
+	int pad;
 } bEditObjectActuator;
 
 typedef struct bSceneActuator {
@@ -439,6 +441,19 @@ typedef struct bActuator {
 /* editObjectActuator->flag */
 #define ACT_TRACK_3D			1
 
+/* editObjectActuator->upflag */
+#define ACT_TRACK_UP_X			0
+#define ACT_TRACK_UP_Y			1
+#define ACT_TRACK_UP_Z			2
+
+/* editObjectActuator->trackflag */
+#define ACT_TRACK_TRAXIS_X			0
+#define ACT_TRACK_TRAXIS_Y			1
+#define ACT_TRACK_TRAXIS_Z			2
+#define ACT_TRACK_TRAXIS_NEGX		3
+#define ACT_TRACK_TRAXIS_NEGY		4
+#define ACT_TRACK_TRAXIS_NEGZ		5
+
 /* editObjectActuator->flag for replace mesh actuator */
 #define ACT_EDOB_REPLACE_MESH_NOGFX		2 /* use for replace mesh actuator */
 #define ACT_EDOB_REPLACE_MESH_PHYS		4
diff --git a/source/blender/makesrna/intern/rna_actuator.c b/source/blender/makesrna/intern/rna_actuator.c
index 62e681d1374..9d26978d098 100644
--- a/source/blender/makesrna/intern/rna_actuator.c
+++ b/source/blender/makesrna/intern/rna_actuator.c
@@ -1369,6 +1369,23 @@ static void rna_def_edit_object_actuator(BlenderRNA *brna)
 		{0, NULL, 0, NULL, NULL}
 	};
 
+	static EnumPropertyItem prop_track_axis_items[] = {
+		{ACT_TRACK_TRAXIS_X, "TRACKAXISX", 0, "X axis", ""},
+		{ACT_TRACK_TRAXIS_Y, "TRACKAXISY", 0, "Y axis", ""},
+		{ACT_TRACK_TRAXIS_Z, "TRACKAXISZ", 0, "Z axis", ""},
+		{ACT_TRACK_TRAXIS_NEGX, "TRACKAXISNEGX", 0, "-X axis", ""},
+		{ACT_TRACK_TRAXIS_NEGY, "TRACKAXISNEGY", 0, "-Y axis", ""},
+		{ACT_TRACK_TRAXIS_NEGZ, "TRACKAXISNEGZ", 0, "-Z axis", ""},
+		{0, NULL, 0, NULL, NULL}
+	};
+
+	static EnumPropertyItem prop_up_axis_items[] = {
+		{ACT_TRACK_UP_X, "UPAXISX", 0, "X axis", ""},
+		{ACT_TRACK_UP_Y, "UPAXISY", 0, "Y axis", ""},
+		{ACT_TRACK_UP_Z, "UPAXISZ", 0, "Z axis", ""},
+		{0, NULL, 0, NULL, NULL}
+	};
+
 	srna = RNA_def_struct(brna, "EditObjectActuator", "Actuator");
 	RNA_def_struct_ui_text(srna, "Edit Object Actuator", "Actuator used to edit objects");
 	RNA_def_struct_sdna_from(srna, "bEditObjectActuator", "data");
@@ -1385,6 +1402,18 @@ static void rna_def_edit_object_actuator(BlenderRNA *brna)
 	RNA_def_property_ui_text(prop, "Dynamic Operation", "");
 	RNA_def_property_update(prop, NC_LOGIC, NULL);
 
+	prop = RNA_def_property(srna, "up_axis", PROP_ENUM, PROP_NONE);
+	RNA_def_property_enum_sdna(prop, NULL, "upflag");
+	RNA_def_property_enum_items(prop, prop_up_axis_items);
+	RNA_def_property_ui_text(prop, "Up Axis", "The axis that points upward");
+	RNA_def_property_update(prop, NC_LOGIC, NULL);
+
+	prop = RNA_def_property(srna, "track_axis", PROP_ENUM, PROP_NONE);
+	RNA_def_property_enum_sdna(prop, NULL, "trackflag");
+	RNA_def_property_enum_items(prop, prop_track_axis_items);
+	RNA_def_property_ui_text(prop, "Track Axis", "The axis that points to the target object");
+	RNA_def_property_update(prop, NC_LOGIC, NULL);
+
 	prop = RNA_def_property(srna, "object", PROP_POINTER, PROP_NONE);
 	RNA_def_property_struct_type(prop, "Object");
 	RNA_def_property_pointer_sdna(prop, NULL, "ob");
diff --git a/source/gameengine/Converter/KX_ConvertActuators.cpp b/source/gameengine/Converter/KX_ConvertActuators.cpp
index 45fc11b97d2..f6ed3366625 100644
--- a/source/gameengine/Converter/KX_ConvertActuators.cpp
+++ b/source/gameengine/Converter/KX_ConvertActuators.cpp
@@ -538,8 +538,8 @@ void BL_ConvertActuators(const char* maggiename,
 						            originalval,
 						            editobact->time,
 						            editobact->flag,
-						            blenderobject->trackflag,
-						            blenderobject->upflag);
+						            editobact->trackflag,
+						            editobact->upflag);
 						baseact = tmptrackact;
 						break;
 					}
diff --git a/source/gameengine/Ketsji/KX_PythonInit.cpp b/source/gameengine/Ketsji/KX_PythonInit.cpp
index fa52fab06fc..bbf9f427a6c 100644
--- a/source/gameengine/Ketsji/KX_PythonInit.cpp
+++ b/source/gameengine/Ketsji/KX_PythonInit.cpp
@@ -88,6 +88,7 @@ extern "C" {
 #include "KX_SteeringActuator.h"
 #include "KX_NavMeshObject.h"
 #include "KX_MouseActuator.h"
+#include "KX_TrackToActuator.h"
 
 #include "SCA_IInputDevice.h"
 #include "SCA_PropertySensor.h"
@@ -1754,6 +1755,17 @@ PyObject *initGameLogic(KX_KetsjiEngine *engine, KX_Scene* scene) // quick hack
 	KX_MACRO_addTypesToDict(d, KX_RAY_AXIS_NEG_Y, KX_RaySensor::KX_RAY_AXIS_NEG_Y);
 	KX_MACRO_addTypesToDict(d, KX_RAY_AXIS_NEG_Z, KX_RaySensor::KX_RAY_AXIS_NEG_Z);
 
+	/* TrackTo Actuator */
+	KX_MACRO_addTypesToDict(d, KX_TRACK_UPAXIS_POS_X, KX_TrackToActuator::KX_TRACK_UPAXIS_POS_X);
+	KX_MACRO_addTypesToDict(d, KX_TRACK_UPAXIS_POS_Y, KX_TrackToActuator::KX_TRACK_UPAXIS_POS_Y);
+	KX_MACRO_addTypesToDict(d, KX_TRACK_UPAXIS_POS_Z, KX_TrackToActuator::KX_TRACK_UPAXIS_POS_Z);
+	KX_MACRO_addTypesToDict(d, KX_TRACK_TRAXIS_POS_X, KX_TrackToActuator::KX_TRACK_TRAXIS_POS_X);
+	KX_MACRO_addTypesToDict(d, KX_TRACK_TRAXIS_POS_Y, KX_TrackToActuator::KX_TRACK_TRAXIS_POS_Y);
+	KX_MACRO_addTypesToDict(d, KX_TRACK_TRAXIS_POS_Z, KX_TrackToActuator::KX_TRACK_TRAXIS_POS_Z);
+	KX_MACRO_addTypesToDict(d, KX_TRACK_TRAXIS_NEG_X, KX_TrackToActuator::KX_TRACK_TRAXIS_NEG_X);
+	KX_MACRO_addTypesToDict(d, KX_TRACK_TRAXIS_NEG_Y, KX_TrackToActuator::KX_TRACK_TRAXIS_NEG_Y);
+	KX_MACRO_addTypesToDict(d, KX_TRACK_TRAXIS_NEG_Z, KX_TrackToActuator::KX_TRACK_TRAXIS_NEG_Z);
+
 	/* Dynamic actuator */
 	KX_MACRO_addTypesToDict(d, KX_DYN_RESTORE_DYNAMICS, KX_SCA_DynamicActuator::KX_DYN_RESTORE_DYNAMICS);
 	KX_MACRO_addTypesToDict(d, KX_DYN_DISABLE_DYNAMICS, KX_SCA_DynamicActuator::KX_DYN_DISABLE_DYNAMICS);
diff --git a/source/gameengine/Ketsji/KX_TrackToActuator.cpp b/source/gameengine/Ketsji/KX_TrackToActuator.cpp
index 90b7850946b..75baf5fac1d 100644
--- a/source/gameengine/Ketsji/KX_TrackToActuator.cpp
+++ b/source/gameengine/Ketsji/KX_TrackToActuator.cpp
@@ -31,8 +31,7 @@
  * Replace the mesh for this actuator's parent
  */
 
-/* todo: not all trackflags / upflags are implemented/tested !
- * m_trackflag is used to determine the forward tracking direction
+/* m_trackflag is used to determine the forward tracking direction
  * m_upflag for the up direction
  * normal situation is +y for forward, +z for up */
 
@@ -177,7 +176,77 @@ static MT_Matrix3x3 matrix3x3_interpol(MT_Matrix3x3 oldmat, MT_Matrix3x3 mat, in
 	return EulToMat3(eul);
 }
 
+static float basis_cross(int n, int m)
+{
+	switch (n - m) {
+		case 1:
+		case -2:
+			return 1.0f;
+
+		case -1:
+		case 2:
+			return -1.0f;
+
+		default:
+			return 0.0f;
+	}
+}
 
+/* vectomat function obtained from constrain.c and modified to work with MOTO library */
+static MT_Matrix3x3 vectomat(MT_Vector3 vec, short axis, short upflag, short threedimup)
+{
+	MT_Matrix3x3 mat;
+	MT_Vector3 y(MT_Scalar(0.0), MT_Scalar(1.0), MT_Scalar(0.0));
+	MT_Vector3 z(MT_Scalar(0.0), MT_Scalar(0.0), MT_Scalar(1.0)); /* world Z axis is the global up axis */
+	MT_Vector3 proj;
+	MT_Vector3 right;
+	MT_Scalar mul;
+	int right_index;
+
+	/* Normalized Vec vector*/
+	vec = vec.safe_normalized_vec(z);
+
+	/* if 2D doesn't move the up vector */
+	if (!threedimup){
+		vec.setValue(MT_Scalar(vec[0]), MT_Scalar(vec[1]), MT_Scalar(0.0));
+		vec = (vec - z.dot(vec)*z).safe_normalized_vec(z);
+	}
+
+	if (axis > 2)
+		axis -= 3;
+	else
+		vec = -vec;
+
+	/* project the up vector onto the plane specified by vec */
+	/* first z onto vec... */
+	mul = z.dot(vec) / vec.dot(vec);
+	proj = vec * mul;
+	/* then onto the plane */
+	proj = z - proj;
+	/* proj specifies the transformation of the up axis */
+	proj = proj.safe_normalized_vec(y);
+
+	/* Normalized cross product of vec and proj specifies transformation of the right axis */
+	right = proj.cross(vec);
+	right.normalize();
+
+	if (axis != upflag) {
+		right_index = 3 - axis - upflag;
+
+		/* account for up direction, track direction */
+		right = right * basis_cross(axis, upflag);
+		mat.setRow(right_index, right);
+		mat.setRow(upflag, proj);
+		mat.setRow(axis, vec);
+		mat = mat.inverse();
+	}
+	/* identity matrix - don't do anything if the two axes are the same */
+	else {
+		mat.setIdentity();
+	}
+
+	return mat;
+}
 
 KX_TrackToActuator::~KX_TrackToActuator()
 {
@@ -247,153 +316,24 @@ bool KX_TrackToActuator::Update(double curtime, bool frame)
 	else if (m_object)
 	{
 		KX_GameObject* curobj = (KX_GameObject*) GetParent();
-		MT_Vector3 dir = ((KX_GameObject*)m_object)->NodeGetWorldPosition() - curobj->NodeGetWorldPosition();
-		if (dir.length2())
-			dir.normalize();
-		MT_Vector3 up(0,0,1);
-		
-		
-#ifdef DSADSA
-		switch (m_upflag)
-		{
-		case 0:
-			{
-				up.setValue(1.0,0,0);
-				break;
-			} 
-		case 1:
-			{
-				up.setValue(0,1.0,0);
-				break;
-			}
-		case 2:
-		default:
-			{
-				up.setValue(0,0,1.0);
-			}
-		}
-#endif 
-		if (m_allow3D)
-		{
-			up = (up - up.dot(dir) * dir).safe_normalized();
-			
-		}
-		else
-		{
-			dir = (dir - up.dot(dir)*up).safe_normalized();
-		}
-		
-		MT_Vector3 left;
+		MT_Vector3 dir = curobj->NodeGetWorldPosition() - ((KX_GameObject*)m_object)->NodeGetWorldPosition();
 		MT_Matrix3x3 mat;
-		
-		switch (m_trackflag)
-		{
-		case 0: // TRACK X
-			{
-				// (1.0 , 0.0 , 0.0 ) x direction is forward, z (0.0 , 0.0 , 1.0 ) up
-				left  = dir.safe_normalized();
-				dir = up.cross(left).safe_normalized();
-				mat.setValue (
-					left[0], dir[0],up[0], 
-					left[1], dir[1],up[1],
-					left[2], dir[2],up[2]
-					);
-				
-				break;
-			};
-		case 1:	// TRACK Y
-			{
-				// (0.0 , 1.0 , 0.0 ) y direction is forward, z (0.0 , 0.0 , 1.0 ) up
-				left  = (dir.cross(up)).safe_normalized();
-				mat.setValue (
-					left[0], dir[0],up[0], 
-					left[1], dir[1],up[1],
-					left[2], dir[2],up[2]
-					);
-				
-				break;
-			}
-			
-		case 2: // track Z
-			{
-				left = up.safe_normalized();
-				up = dir.safe_normalized();
-				dir = left;
-				left  = (dir.cross(up)).safe_normalized();
-				mat.setValue (
-					left[0], dir[0],up[0], 
-					left[1], dir[1],up[1],
-					left[2], dir[2],up[2]
-					);
-				break;
-			}
-			
-		case 3: // TRACK -X
-			{
-				// (1.0 , 0.0 , 0.0 ) x direction is forward, z (0.0 , 0.0 , 1.0 ) up
-				left  = -dir.safe_normalized();
-				dir = up.cross(left).safe_normalized();
-				mat.setValue (
-					left[0], dir[0],up[0], 
-					left[1], dir[1],up[1],
-					left[2], dir[2],up[2]
-					);
-				
-				break;
-			};
-		case 4: // TRACK -Y
-			{
-				// (0.0 , -1.0 , 0.0 ) -y direction is forward, z (0.0 , 0.0 , 1.0 ) up
-				left  = (-dir.cross(up)).safe_normalized();
-				mat.setValue (
-					left[0], -dir[0],up[0], 
-					left[1], -dir[1],up[1],
-					left[2], -dir[2],up[2]
-					);
-				break;
-			}
-		case 5: // track -Z
-			{
-				left = up.safe_normalized();
-				up = -dir.safe_normalized();
-				dir = left;
-				left  = (dir.cross(up)).safe_normalized();
-				mat.setValue (
-					left[0], dir[0],up[0], 
-					left[1], dir[1],up[1],
-					left[2], dir[2],up[2]
-					);
-				
-				break;
-			}
-			
-		default:
-			{
-				// (1.0 , 0.0 , 0.0 ) -x direction is forward, z (0.0 , 0.0 , 1.0 ) up
-				left  = -dir.safe_normalized();
-				dir = up.cross(left).safe_normalized();
-				mat.setValue (
-					left[0], dir[0],up[0], 
-					left[1], dir[1],up[1],
-					left[2], dir[2],up[2]
-					);
-			}
-		}
-		
 		MT_Matrix3x3 oldmat;
-		oldmat= curobj->NodeGetWorldOrientation();
+
+		mat = vectomat(dir, m_trackflag, m_upflag, m_allow3D);
+		oldmat = curobj->NodeGetWorldOrientation();
 		
 		/* erwin should rewrite this! */
-		mat= matrix3x3_interpol(oldmat, mat, m_time);
+		mat = matrix3x3_interpol(oldmat, mat, m_time);
 		
-
-		if (m_parentobj) { // check if the model is parented and calculate the child transform
+		/* check if the model is parented and calculate the child transform */
+		if (m_parentobj) {
 				
 			MT_Point3 localpos;
 			localpos = curobj->GetSGNode()->GetLocalPosition();
 			// Get the inverse of the parent matrix
 			MT_Matrix3x3 parentmatinv;
-			parentmatinv = m_parentobj->NodeGetWorldOrientation ().inverse ();
+			parentmatinv = m_parentobj->NodeGetWorldOrientation().inverse();
 			// transform the local coordinate system into the parents system
 			mat = parentmatinv * mat;
 			// append the initial parent local rotation matrix
@@ -404,8 +344,7 @@ bool KX_TrackToActuator::Update(double curtime, bool frame)
 			curobj->NodeSetLocalPosition(localpos);
 			//curobj->UpdateTransform();
 		}
-		else
-		{
+		else {
 			curobj->NodeSetLocalOrientation(mat);
 		}
 
@@ -451,6 +390,8 @@ PyMethodDef KX_TrackToActuator::Methods[] = {
 PyAttributeDef KX_TrackToActuator::Attributes[] = {
 	KX_PYATTRIBUTE_INT_RW("time",0,1000,true,KX_TrackToActuator,m_time),
 	KX_PYATTRIBUTE_BOOL_RW("use3D",KX_TrackToActuator,m_allow3D),
+	KX_PYATTRIBUTE_INT_RW("upAxis", 0, 2, true, KX_TrackToActuator,m_upflag),
+	KX_PYATTRIBUTE_INT_RW("trackAxis", 0, 5, true, KX_TrackToActuator,m_trackflag),
 	KX_PYATTRIBUTE_RW_FUNCTION("object", KX_TrackToActuator, pyattr_get_object, pyattr_set_object),
 
 	{ NULL }	//Sentinel
diff --git a/source/gameengine/Ketsji/KX_TrackToActuator.h b/source/gameengine/Ketsji/KX_TrackToActuator.h
index 4df240a0063..124014eede2 100644
--- a/source/gameengine/Ketsji/KX_TrackToActuator.h
+++ b/source/gameengine/Ketsji/KX_TrackToActuator.h
@@ -68,6 +68,21 @@ class KX_TrackToActuator : public SCA_IActuator
 	virtual void Relink(CTR_Map<CTR_HashedPtr, void*> *obj_map);
 	virtual bool Update(double curtime, bool frame);
 
+	//Python Interface
+	enum UpAxis {
+		KX_TRACK_UPAXIS_POS_X = 0,
+		KX_TRACK_UPAXIS_POS_Y,
+		KX_TRACK_UPAXIS_POS_Z
+	};
+	enum TrackAxis {
+		KX_TRACK_TRAXIS_POS_X = 0,
+		KX_TRACK_TRAXIS_POS_Y,
+		KX_TRACK_TRAXIS_POS_Z,
+		KX_TRACK_TRAXIS_NEG_X,
+		KX_TRACK_TRAXIS_NEG_Y,
+		KX_TRACK_TRAXIS_NEG_Z
+	};
+
 #ifdef WITH_PYTHON
 
 	/* Python part */