BGE: Fix T41502 Path following jumping

New Lock Z velocity parameter was added. This parameter avoid the micro-jumping.
By default it is actived except when you load an old file that it is deactived to keep former behaviour.

Additionally it was solved another issue related with the acceleration: That is the acceleration value was not taked into account and we had always the maximum linear velocity from the beginning of movement. Now the acceleration is taken into account until we reach the maximum velocity.
When you load an old file, the acceleration value is set to the maximum range (1000.f). This way we simulate a maximum velocity constant from the beginning of movement (former behaviour).

{F142195}

Reviewers: moguri, dfelinto, campbellbarton

Reviewed By: campbellbarton

Subscribers: sergey

Differential Revision: https://developer.blender.org/D1074

8 files changed, 48 insertions, 13 deletions

diff --git a/source/blender/blenkernel/intern/sca.c b/source/blender/blenkernel/intern/sca.c
index 9159c9e9afc..c902659c039 100644
--- a/source/blender/blenkernel/intern/sca.c
+++ b/source/blender/blenkernel/intern/sca.c
@@ -496,7 +496,7 @@ void init_actuator(bActuator *act)
 		sta->turnspeed = 120.f;
 		sta->dist = 1.f;
 		sta->velocity= 3.f;
-		sta->flag = ACT_STEERING_AUTOMATICFACING;
+		sta->flag = ACT_STEERING_AUTOMATICFACING | ACT_STEERING_LOCKZVEL;
 		sta->facingaxis = 1;
 		break;
 	case ACT_MOUSE:
diff --git a/source/blender/blenloader/intern/versioning_270.c b/source/blender/blenloader/intern/versioning_270.c
index 1afdc348c24..f4591e4d107 100644
--- a/source/blender/blenloader/intern/versioning_270.c
+++ b/source/blender/blenloader/intern/versioning_270.c
@@ -616,5 +616,17 @@ void blo_do_versions_270(FileData *fd, Library *UNUSED(lib), Main *main)
 				}
 			}
 		}
+
+		if (!DNA_struct_elem_find(fd->filesdna, "bSteeringActuator", "float", "acceleration")) {
+			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_STEERING) {
+						bSteeringActuator *sact = act->data;
+						sact->acceleration = 1000.f;
+					}
+				}
+			}
+		}
 	}
 }
diff --git a/source/blender/editors/space_logic/logic_window.c b/source/blender/editors/space_logic/logic_window.c
index 37c634672df..7204144ce85 100644
--- a/source/blender/editors/space_logic/logic_window.c
+++ b/source/blender/editors/space_logic/logic_window.c
@@ -2105,12 +2105,15 @@ static void draw_actuator_steering(uiLayout *layout, PointerRNA *ptr)
 	}
 
 	row = uiLayoutRow(layout, false);
-	uiItemR(row, ptr, "self_terminated", 0, NULL, ICON_NONE);
+	col = uiLayoutColumn(row, false);
+	uiItemR(col, ptr, "self_terminated", 0, NULL, ICON_NONE);
 	if (RNA_enum_get(ptr, "mode")==ACT_STEERING_PATHFOLLOWING) {
-		uiItemR(row, ptr, "update_period", 0, NULL, ICON_NONE);
-		row = uiLayoutRow(layout, false);
+		col = uiLayoutColumn(row, false);
+		uiItemR(col, ptr, "update_period", 0, NULL, ICON_NONE);
 	}
 	row = uiLayoutRow(layout, false);
+	uiItemR(row, ptr, "lock_z_velocity", 1, NULL, ICON_NONE);
+	row = uiLayoutRow(layout, false);
 	uiItemR(row, ptr, "show_visualization", 0, NULL, ICON_NONE);
 	if (RNA_enum_get(ptr, "mode") != ACT_STEERING_PATHFOLLOWING) {
 		uiLayoutSetActive(row, false);
diff --git a/source/blender/makesdna/DNA_actuator_types.h b/source/blender/makesdna/DNA_actuator_types.h
index bdf1b62646d..9af0c1dac10 100644
--- a/source/blender/makesdna/DNA_actuator_types.h
+++ b/source/blender/makesdna/DNA_actuator_types.h
@@ -570,6 +570,7 @@ typedef struct bActuator {
 #define ACT_STEERING_ENABLEVISUALIZATION   2
 #define ACT_STEERING_AUTOMATICFACING   4
 #define ACT_STEERING_NORMALUP  8
+#define ACT_STEERING_LOCKZVEL  16
 
 /* mouseactuator->type */
 #define ACT_MOUSE_VISIBILITY	0
diff --git a/source/blender/makesrna/intern/rna_actuator.c b/source/blender/makesrna/intern/rna_actuator.c
index 6f2c968764c..83a6d728d80 100644
--- a/source/blender/makesrna/intern/rna_actuator.c
+++ b/source/blender/makesrna/intern/rna_actuator.c
@@ -2056,6 +2056,11 @@ static void rna_def_steering_actuator(BlenderRNA *brna)
 	RNA_def_property_boolean_sdna(prop, NULL, "flag", ACT_STEERING_NORMALUP);
 	RNA_def_property_ui_text(prop, "N", "Use normal of the navmesh to set \"UP\" vector");
 	RNA_def_property_update(prop, NC_LOGIC, NULL);
+
+	prop = RNA_def_property(srna, "lock_z_velocity", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_sdna(prop, NULL, "flag", ACT_STEERING_LOCKZVEL);
+	RNA_def_property_ui_text(prop, "Lock Z velocity", "Disable simulation of linear motion along Z axis");
+	RNA_def_property_update(prop, NC_LOGIC, NULL);
 }
 
 static void rna_def_mouse_actuator(BlenderRNA *brna)
diff --git a/source/gameengine/Converter/KX_ConvertActuators.cpp b/source/gameengine/Converter/KX_ConvertActuators.cpp
index f6ed3366625..ff4b5a61d12 100644
--- a/source/gameengine/Converter/KX_ConvertActuators.cpp
+++ b/source/gameengine/Converter/KX_ConvertActuators.cpp
@@ -1087,11 +1087,12 @@ void BL_ConvertActuators(const char* maggiename,
 				bool enableVisualization = (stAct->flag & ACT_STEERING_ENABLEVISUALIZATION) !=0;
 				short facingMode = (stAct->flag & ACT_STEERING_AUTOMATICFACING) ? stAct->facingaxis : 0;
 				bool normalup = (stAct->flag & ACT_STEERING_NORMALUP) !=0;
+				bool lockzvel = (stAct->flag & ACT_STEERING_LOCKZVEL) !=0;
 				KX_SteeringActuator *tmpstact
 					= new KX_SteeringActuator(gameobj, mode, targetob, navmeshob,stAct->dist, 
 					stAct->velocity, stAct->acceleration, stAct->turnspeed, 
 					selfTerminated, stAct->updateTime,
-					scene->GetObstacleSimulation(), facingMode, normalup, enableVisualization);
+					scene->GetObstacleSimulation(), facingMode, normalup, enableVisualization, lockzvel);
 				baseact = tmpstact;
 				break;
 			}
diff --git a/source/gameengine/Ketsji/KX_SteeringActuator.cpp b/source/gameengine/Ketsji/KX_SteeringActuator.cpp
index ff192299702..10d4273a2b4 100644
--- a/source/gameengine/Ketsji/KX_SteeringActuator.cpp
+++ b/source/gameengine/Ketsji/KX_SteeringActuator.cpp
@@ -41,7 +41,7 @@
 /* Native functions                                                          */
 /* ------------------------------------------------------------------------- */
 
-KX_SteeringActuator::KX_SteeringActuator(SCA_IObject *gameobj, 
+KX_SteeringActuator::KX_SteeringActuator(SCA_IObject *gameobj,
                                          int mode,
                                          KX_GameObject *target,
                                          KX_GameObject *navmesh,
@@ -54,7 +54,8 @@ KX_SteeringActuator::KX_SteeringActuator(SCA_IObject *gameobj,
                                          KX_ObstacleSimulation* simulation,
                                          short facingmode,
                                          bool normalup,
-                                         bool enableVisualization)
+                                         bool enableVisualization,
+                                         bool lockzvel)
     : SCA_IActuator(gameobj, KX_ACT_STEERING),
       m_target(target),
       m_mode(mode),
@@ -72,6 +73,7 @@ KX_SteeringActuator::KX_SteeringActuator(SCA_IObject *gameobj,
       m_normalUp(normalup),
       m_pathLen(0),
       m_pathUpdatePeriod(pathUpdatePeriod),
+      m_lockzvel(lockzvel),
       m_wayPointIdx(-1),
       m_steerVec(MT_Vector3(0, 0, 0))
 {
@@ -261,19 +263,19 @@ bool KX_SteeringActuator::Update(double curtime, bool frame)
 
 		if (apply_steerforce)
 		{
+			MT_Vector3 newvel;
 			bool isdyna = obj->IsDynamic();
 			if (isdyna)
 				m_steerVec.z() = 0;
 			if (!m_steerVec.fuzzyZero())
 				m_steerVec.normalize();
-			MT_Vector3 newvel = m_velocity*m_steerVec;
 
 			//adjust velocity to avoid obstacles
 			if (m_simulation && m_obstacle /*&& !newvel.fuzzyZero()*/)
 			{
 				if (m_enableVisualization)
 					KX_RasterizerDrawDebugLine(mypos, mypos + newvel, MT_Vector3(1.0, 0.0, 0.0));
-				m_simulation->AdjustObstacleVelocity(m_obstacle, m_mode!=KX_STEERING_PATHFOLLOWING ? m_navmesh : NULL, 
+				m_simulation->AdjustObstacleVelocity(m_obstacle, m_mode!=KX_STEERING_PATHFOLLOWING ? m_navmesh : NULL,
 								newvel, m_acceleration*delta, m_turnspeed/180.0f*M_PI*delta);
 				if (m_enableVisualization)
 					KX_RasterizerDrawDebugLine(mypos, mypos + newvel, MT_Vector3(0.0, 1.0, 0.0));
@@ -282,10 +284,18 @@ bool KX_SteeringActuator::Update(double curtime, bool frame)
 			HandleActorFace(newvel);
 			if (isdyna)
 			{
-				//temporary solution: set 2D steering velocity directly to obj
-				//correct way is to apply physical force
+				//TODO: Take into account angular velocity on turns
 				MT_Vector3 curvel = obj->GetLinearVelocity();
-				newvel.z() = curvel.z();
+
+				newvel = (curvel.length() * m_steerVec) + (m_acceleration * delta) * m_steerVec;
+				if (newvel.length2() >= (m_velocity * m_velocity))
+					newvel = m_velocity * m_steerVec;
+
+				if (m_lockzvel)
+					newvel.z() = 0.0f;
+				else
+					newvel.z() = curvel.z();
+
 				obj->setLinearVelocity(newvel, false);
 			}
 			else
@@ -554,6 +564,7 @@ PyAttributeDef KX_SteeringActuator::Attributes[] = {
 	KX_PYATTRIBUTE_RO_FUNCTION("steeringVec", KX_SteeringActuator, pyattr_get_steeringVec),
 	KX_PYATTRIBUTE_SHORT_RW("facingMode", 0, 6, true, KX_SteeringActuator, m_facingMode),
 	KX_PYATTRIBUTE_INT_RW("pathUpdatePeriod", -1, 100000, true, KX_SteeringActuator, m_pathUpdatePeriod),
+    KX_PYATTRIBUTE_BOOL_RW("lockZVelocity", KX_SteeringActuator, m_lockzvel),
 	{ NULL }	//Sentinel
 };
 
diff --git a/source/gameengine/Ketsji/KX_SteeringActuator.h b/source/gameengine/Ketsji/KX_SteeringActuator.h
index 1e8ac9a54f0..3273471c166 100644
--- a/source/gameengine/Ketsji/KX_SteeringActuator.h
+++ b/source/gameengine/Ketsji/KX_SteeringActuator.h
@@ -62,6 +62,7 @@ class KX_SteeringActuator : public SCA_IActuator
 	int m_pathLen;
 	int m_pathUpdatePeriod;
 	double m_pathUpdateTime;
+	bool m_lockzvel;
 	int m_wayPointIdx;
 	MT_Matrix3x3 m_parentlocalmat;
 	MT_Vector3 m_steerVec;
@@ -89,7 +90,8 @@ public:
 						KX_ObstacleSimulation* simulation,
 						short facingmode,
 						bool normalup,
-						bool enableVisualization);
+						bool enableVisualization,
+	                    bool lockzvel);
 	virtual ~KX_SteeringActuator();
 	virtual bool Update(double curtime, bool frame);