BGE Physics

Clamp objects min/max velocity.
Accessed with bullet physics from the advanced button with dynamic and rigid body objects.
- useful for preventing unstable physics in cases where objects move too fast.
- can add linear velocity with the motion actuator to give smooth motion transitions, without moving too fast.
- minimum velocity means objects don't stop moving.
- python scripts can adjust these values speedup or throttle velocity in the existing direction.

Also made copy properties from an object with no properties work (in case you want to clear all props)

15 files changed, 176 insertions, 20 deletions

diff --git a/source/blender/makesdna/DNA_object_types.h b/source/blender/makesdna/DNA_object_types.h
index 3a408404b0b..82da883df4a 100644
--- a/source/blender/makesdna/DNA_object_types.h
+++ b/source/blender/makesdna/DNA_object_types.h
@@ -157,7 +157,9 @@ typedef struct Object {
 	float formfactor;
 	float rdamping, sizefac;
 	float margin;
-	int   pad3;
+	float max_vel; /* clamp the maximum velocity 0.0 is disabled */
+	float min_vel; /* clamp the maximum velocity 0.0 is disabled */
+	float pad3; /* clamp the maximum velocity 0.0 is disabled */
 
 	char dt, dtx;
 	char totcol;	/* copy of mesh or curve or meta */
diff --git a/source/blender/src/buttons_logic.c b/source/blender/src/buttons_logic.c
index 2f68720acb0..67531e9b3b8 100644
--- a/source/blender/src/buttons_logic.c
+++ b/source/blender/src/buttons_logic.c
@@ -3139,6 +3139,7 @@ static uiBlock *advanced_bullet_menu(void *arg_ob)
 			uiDefButF(block, NUM, 0, "Margin", 
 					xco, yco, 180, 19, &ob->margin, 0.001, 1.0, 1, 0, 
 					"Collision margin");
+			
 			yco -= 20;
 
 			if (ob->gameflag & OB_RIGID_BODY)
@@ -3166,7 +3167,24 @@ static uiBlock *advanced_bullet_menu(void *arg_ob)
 				uiDefButBitI(block, TOG, OB_LOCK_RIGID_BODY_Z_ROT_AXIS, 0, "Lock Z Rot Axis", 
 					xco+=180, yco, 180, 19, &ob->gameflag2, 0, 0, 0, 0, 
 					"Disable simulation of angular motion along the Z axis");
+				yco -= 20;
 			}
+			xco = 0;
+			
+			uiBlockEndAlign(block);
+			
+			uiDefBut(block, LABEL, 0, "Clamp Velocity (zero disables)",	  xco, yco, 180*2, 19, NULL, 0, 0, 0, 0, "");
+			
+			uiBlockBeginAlign(block);
+			
+			uiDefButF(block, NUM, 0, "Min", 
+				xco+=180, yco, 90, 19, &ob->min_vel, 0.0, 1000.0, 1, 0, 
+				"Clamp velocity to this minimum speed (except when totally still)");
+			uiDefButF(block, NUM, 0, "Max", 
+				xco+=90, yco, 90, 19, &ob->max_vel, 0.0, 1000.0, 1, 0, 
+				"Clamp velocity to this maximum speed");
+			uiBlockEndAlign(block);
+			
 			/*
 			uiDefButBitI(block, TOG, OB_BSB_COL_CL_RS, 0, "Cluster Collision RS", 
 				xco, yco, 180, 19, &ob->bsoft->collisionflags, 0, 0, 0, 0, 
diff --git a/source/blender/src/editobject.c b/source/blender/src/editobject.c
index bb9be49c347..2f127f9a3ec 100644
--- a/source/blender/src/editobject.c
+++ b/source/blender/src/editobject.c
@@ -3205,14 +3205,12 @@ static void copymenu_properties(Object *ob)
 		prop= prop->next;
 	}
 	
-	if(tot==0) {
-		error("No properties in the active object to copy");
-		return;
-	}
-	
 	str= MEM_callocN(50 + 33*tot, "copymenu prop");
 	
-	strcpy(str, "Copy Property %t|Replace All|Merge All|%l");
+	if (tot)
+		strcpy(str, "Copy Property %t|Replace All|Merge All|%l");
+	else
+		strcpy(str, "Copy Property %t|Clear All (no properties on active)");
 	
 	tot= 0;	
 	prop= ob->prop.first;
@@ -3526,7 +3524,8 @@ void copy_attr(short event)
 					base->object->formfactor = ob->formfactor;
 					base->object->damping= ob->damping;
 					base->object->rdamping= ob->rdamping;
-					base->object->mass= ob->mass;
+					base->object->min_vel= ob->min_vel;
+					base->object->max_vel= ob->max_vel;
 					if (ob->gameflag & OB_BOUNDS) {
 						base->object->boundtype = ob->boundtype;
 					}
diff --git a/source/gameengine/Converter/BL_BlenderDataConversion.cpp b/source/gameengine/Converter/BL_BlenderDataConversion.cpp
index 5de2c4a2fe7..2ae47e47d74 100644
--- a/source/gameengine/Converter/BL_BlenderDataConversion.cpp
+++ b/source/gameengine/Converter/BL_BlenderDataConversion.cpp
@@ -1107,6 +1107,10 @@ static PHY_ShapeProps *CreateShapePropsFromBlenderObject(struct Object* blendero
 	shapeProps->m_do_fh     = (blenderobject->gameflag & OB_DO_FH) != 0; 
 	shapeProps->m_do_rot_fh = (blenderobject->gameflag & OB_ROT_FH) != 0;
 	
+//	velocity clamping XXX
+	shapeProps->m_clamp_vel_min = blenderobject->min_vel;
+	shapeProps->m_clamp_vel_max = blenderobject->max_vel;
+	
 	return shapeProps;
 }
 
diff --git a/source/gameengine/Ketsji/KX_BulletPhysicsController.cpp b/source/gameengine/Ketsji/KX_BulletPhysicsController.cpp
index c621f11994a..831f9241fec 100644
--- a/source/gameengine/Ketsji/KX_BulletPhysicsController.cpp
+++ b/source/gameengine/Ketsji/KX_BulletPhysicsController.cpp
@@ -59,6 +59,24 @@ void	KX_BulletPhysicsController::applyImpulse(const MT_Point3& attach, const MT_
 
 }
 
+float KX_BulletPhysicsController::GetLinVelocityMin()
+{
+	return (float)CcdPhysicsController::GetLinVelocityMin();
+}
+void  KX_BulletPhysicsController::SetLinVelocityMin(float val)
+{
+	CcdPhysicsController::SetLinVelocityMin(val);
+}
+
+float KX_BulletPhysicsController::GetLinVelocityMax()
+{
+	return (float)CcdPhysicsController::GetLinVelocityMax();
+}
+void  KX_BulletPhysicsController::SetLinVelocityMax(float val)
+{
+	CcdPhysicsController::SetLinVelocityMax(val);
+}
+
 void	KX_BulletPhysicsController::SetObject (SG_IObject* object)
 {
 	SG_Controller::SetObject(object);
@@ -73,6 +91,10 @@ void	KX_BulletPhysicsController::SetObject (SG_IObject* object)
 
 }
 
+MT_Scalar KX_BulletPhysicsController::GetRadius()
+{
+	return MT_Scalar(CcdPhysicsController::GetRadius());
+}
 
 void	KX_BulletPhysicsController::setMargin (float collisionMargin)
 {
@@ -176,11 +198,6 @@ MT_Vector3 KX_BulletPhysicsController::GetLocalInertia()
     return inertia;
 }
 
-MT_Scalar KX_BulletPhysicsController::GetRadius()
-{
-	return MT_Scalar(CcdPhysicsController::GetRadius());
-}
-
 MT_Vector3	KX_BulletPhysicsController::getReactionForce()
 {
 	assert(0);
diff --git a/source/gameengine/Ketsji/KX_BulletPhysicsController.h b/source/gameengine/Ketsji/KX_BulletPhysicsController.h
index 9821b3fd253..b39098206f7 100644
--- a/source/gameengine/Ketsji/KX_BulletPhysicsController.h
+++ b/source/gameengine/Ketsji/KX_BulletPhysicsController.h
@@ -56,7 +56,11 @@ public:
 	virtual	SG_Controller*	GetReplica(class SG_Node* destnode);
 
 	virtual MT_Scalar GetRadius();
-
+	
+	virtual float GetLinVelocityMin();
+	virtual void  SetLinVelocityMin(float val);
+	virtual float GetLinVelocityMax();
+	virtual void  SetLinVelocityMax(float val);
 
 	virtual void	SetSumoTransform(bool nondynaonly);
 	// todo: remove next line !
diff --git a/source/gameengine/Ketsji/KX_ConvertPhysicsObjects.cpp b/source/gameengine/Ketsji/KX_ConvertPhysicsObjects.cpp
index 03149859f4d..08e2ea30414 100644
--- a/source/gameengine/Ketsji/KX_ConvertPhysicsObjects.cpp
+++ b/source/gameengine/Ketsji/KX_ConvertPhysicsObjects.cpp
@@ -801,6 +801,8 @@ void	KX_ConvertBulletObject(	class	KX_GameObject* gameobj,
 	ci.m_gravity = btVector3(0,0,0);
 	ci.m_localInertiaTensor =btVector3(0,0,0);
 	ci.m_mass = objprop->m_dyna ? shapeprops->m_mass : 0.f;
+	ci.m_clamp_vel_min = shapeprops->m_clamp_vel_min;
+	ci.m_clamp_vel_max = shapeprops->m_clamp_vel_max;
 	ci.m_margin = objprop->m_margin;
 	shapeInfo->m_radius = objprop->m_radius;
 	isbulletdyna = objprop->m_dyna;
diff --git a/source/gameengine/Ketsji/KX_GameObject.cpp b/source/gameengine/Ketsji/KX_GameObject.cpp
index 16cf3d9ae32..a399d3b477a 100644
--- a/source/gameengine/Ketsji/KX_GameObject.cpp
+++ b/source/gameengine/Ketsji/KX_GameObject.cpp
@@ -1086,6 +1086,8 @@ PyAttributeDef KX_GameObject::Attributes[] = {
 	KX_PYATTRIBUTE_RO_FUNCTION("name",		KX_GameObject, pyattr_get_name),
 	KX_PYATTRIBUTE_RO_FUNCTION("parent",	KX_GameObject, pyattr_get_parent),
 	KX_PYATTRIBUTE_RW_FUNCTION("mass",		KX_GameObject, pyattr_get_mass,		pyattr_set_mass),
+	KX_PYATTRIBUTE_RW_FUNCTION("linVelocityMin",		KX_GameObject, pyattr_get_lin_vel_min, pyattr_set_lin_vel_min),
+	KX_PYATTRIBUTE_RW_FUNCTION("linVelocityMax",		KX_GameObject, pyattr_get_lin_vel_max, pyattr_set_lin_vel_max),
 	KX_PYATTRIBUTE_RW_FUNCTION("visible",	KX_GameObject, pyattr_get_visible,	pyattr_set_visible),
 	KX_PYATTRIBUTE_BOOL_RW    ("occlusion", KX_GameObject, m_bOccluder),
 	KX_PYATTRIBUTE_RW_FUNCTION("position",	KX_GameObject, pyattr_get_position,	pyattr_set_position),
@@ -1364,6 +1366,53 @@ int KX_GameObject::pyattr_set_mass(void *self_v, const KX_PYATTRIBUTE_DEF *attrd
 	return 0;
 }
 
+PyObject* KX_GameObject::pyattr_get_lin_vel_min(void *self_v, const KX_PYATTRIBUTE_DEF *attrdef)
+{
+	KX_GameObject* self= static_cast<KX_GameObject*>(self_v);
+	KX_IPhysicsController *spc = self->GetPhysicsController();
+	return PyFloat_FromDouble(spc ? spc->GetLinVelocityMax() : 0.0f);
+}
+
+int KX_GameObject::pyattr_set_lin_vel_min(void *self_v, const KX_PYATTRIBUTE_DEF *attrdef, PyObject *value)
+{
+	KX_GameObject* self= static_cast<KX_GameObject*>(self_v);
+	KX_IPhysicsController *spc = self->GetPhysicsController();
+	MT_Scalar val = PyFloat_AsDouble(value);
+	if (val < 0.0f) { /* also accounts for non float */
+		PyErr_SetString(PyExc_AttributeError, "expected a float zero or above");
+		return 1;
+	}
+
+	if (spc)
+		spc->SetLinVelocityMin(val);
+
+	return 0;
+}
+
+PyObject* KX_GameObject::pyattr_get_lin_vel_max(void *self_v, const KX_PYATTRIBUTE_DEF *attrdef)
+{
+	KX_GameObject* self= static_cast<KX_GameObject*>(self_v);
+	KX_IPhysicsController *spc = self->GetPhysicsController();
+	return PyFloat_FromDouble(spc ? spc->GetLinVelocityMax() : 0.0f);
+}
+
+int KX_GameObject::pyattr_set_lin_vel_max(void *self_v, const KX_PYATTRIBUTE_DEF *attrdef, PyObject *value)
+{
+	KX_GameObject* self= static_cast<KX_GameObject*>(self_v);
+	KX_IPhysicsController *spc = self->GetPhysicsController();
+	MT_Scalar val = PyFloat_AsDouble(value);
+	if (val < 0.0f) { /* also accounts for non float */
+		PyErr_SetString(PyExc_AttributeError, "expected a float zero or above");
+		return 1;
+	}
+
+	if (spc)
+		spc->SetLinVelocityMax(val);
+
+	return 0;
+}
+
+
 PyObject* KX_GameObject::pyattr_get_visible(void *self_v, const KX_PYATTRIBUTE_DEF *attrdef)
 {
 	KX_GameObject* self= static_cast<KX_GameObject*>(self_v);
diff --git a/source/gameengine/Ketsji/KX_GameObject.h b/source/gameengine/Ketsji/KX_GameObject.h
index c389d6cc776..94192580859 100644
--- a/source/gameengine/Ketsji/KX_GameObject.h
+++ b/source/gameengine/Ketsji/KX_GameObject.h
@@ -960,6 +960,10 @@ public:
 
 	static PyObject*	pyattr_get_mass(void *self_v, const KX_PYATTRIBUTE_DEF *attrdef);
 	static int			pyattr_set_mass(void *self_v, const KX_PYATTRIBUTE_DEF *attrdef, PyObject *value);
+	static PyObject*	pyattr_get_lin_vel_min(void *self_v, const KX_PYATTRIBUTE_DEF *attrdef);
+	static int			pyattr_set_lin_vel_min(void *self_v, const KX_PYATTRIBUTE_DEF *attrdef, PyObject *value);
+	static PyObject*	pyattr_get_lin_vel_max(void *self_v, const KX_PYATTRIBUTE_DEF *attrdef);
+	static int			pyattr_set_lin_vel_max(void *self_v, const KX_PYATTRIBUTE_DEF *attrdef, PyObject *value);
 	static PyObject*	pyattr_get_visible(void *self_v, const KX_PYATTRIBUTE_DEF *attrdef);
 	static int			pyattr_set_visible(void *self_v, const KX_PYATTRIBUTE_DEF *attrdef, PyObject *value);
 	static PyObject*	pyattr_get_position(void *self_v, const KX_PYATTRIBUTE_DEF *attrdef);
diff --git a/source/gameengine/Ketsji/KX_IPhysicsController.h b/source/gameengine/Ketsji/KX_IPhysicsController.h
index b7603203241..10b66da7b76 100644
--- a/source/gameengine/Ketsji/KX_IPhysicsController.h
+++ b/source/gameengine/Ketsji/KX_IPhysicsController.h
@@ -79,6 +79,12 @@ public:
 	virtual	void setScaling(const MT_Vector3& scaling)=0;
 	virtual	MT_Scalar	GetMass()=0;
 	virtual void	SetMass(MT_Scalar newmass)=0;
+	
+	virtual	float GetLinVelocityMin()=0;
+	virtual void	SetLinVelocityMin(float newmass)=0;
+	virtual	float GetLinVelocityMax()=0;
+	virtual void	SetLinVelocityMax(float newmass)=0;
+	
 	virtual	MT_Vector3	GetLocalInertia()=0;
 	virtual	MT_Vector3	getReactionForce()=0;
 	virtual void	setRigidBody(bool rigid)=0;
diff --git a/source/gameengine/Physics/Bullet/CcdPhysicsController.cpp b/source/gameengine/Physics/Bullet/CcdPhysicsController.cpp
index 2283968801f..0b9da8f46d3 100644
--- a/source/gameengine/Physics/Bullet/CcdPhysicsController.cpp
+++ b/source/gameengine/Physics/Bullet/CcdPhysicsController.cpp
@@ -584,7 +584,19 @@ bool		CcdPhysicsController::SynchronizeMotionStates(float time)
 
 	if (body && !body->isStaticObject())
 	{
-
+		
+		if ((m_cci.m_clamp_vel_max>0.0) || (m_cci.m_clamp_vel_min>0.0))
+		{
+			const btVector3& linvel = body->getLinearVelocity();
+			float len= linvel.length();
+			
+			if((m_cci.m_clamp_vel_max>0.0) && (len > m_cci.m_clamp_vel_max))
+					body->setLinearVelocity(linvel * (m_cci.m_clamp_vel_max / len));
+			
+			else if ((m_cci.m_clamp_vel_min>0.0) && btFuzzyZero(len)==0 && (len < m_cci.m_clamp_vel_min))
+				body->setLinearVelocity(linvel * (m_cci.m_clamp_vel_min / len));
+		}
+		
 		const btVector3& worldPos = body->getCenterOfMassPosition();
 		m_MotionState->setWorldPosition(worldPos[0],worldPos[1],worldPos[2]);
 		
diff --git a/source/gameengine/Physics/Bullet/CcdPhysicsController.h b/source/gameengine/Physics/Bullet/CcdPhysicsController.h
index 245cde2baaa..c7638b36728 100644
--- a/source/gameengine/Physics/Bullet/CcdPhysicsController.h
+++ b/source/gameengine/Physics/Bullet/CcdPhysicsController.h
@@ -214,6 +214,8 @@ struct CcdConstructionInfo
 		m_gravity(0,0,0),
 		m_scaling(1.f,1.f,1.f),
 		m_mass(0.f),
+		m_clamp_vel_min(-1.f), 
+		m_clamp_vel_max(-1.f), 
 		m_restitution(0.1f),
 		m_friction(0.5f),
 		m_linearDamping(0.1f),
@@ -239,6 +241,8 @@ struct CcdConstructionInfo
 	btVector3	m_gravity;
 	btVector3	m_scaling;
 	btScalar	m_mass;
+	btScalar	m_clamp_vel_min;  
+	btScalar	m_clamp_vel_max;  
 	btScalar	m_restitution;
 	btScalar	m_friction;
 	btScalar	m_linearDamping;
@@ -479,7 +483,24 @@ class CcdPhysicsController : public PHY_IPhysicsController
 			}
 			m_cci.m_radius = margin;
 		}
-
+		
+		// velocity clamping
+		virtual void SetLinVelocityMin(float val) 
+		{
+			m_cci.m_clamp_vel_min= val;
+		}
+		virtual float GetLinVelocityMin() const 
+		{
+			return m_cci.m_clamp_vel_min;
+		}
+		virtual void SetLinVelocityMax(float val) 
+		{
+			m_cci.m_clamp_vel_max= val;
+		}
+		virtual float GetLinVelocityMax() const 
+		{
+			return m_cci.m_clamp_vel_max;
+		}
 
 		bool	wantsSleeping();
 
diff --git a/source/gameengine/Physics/common/PHY_IPhysicsController.h b/source/gameengine/Physics/common/PHY_IPhysicsController.h
index 6cba6fa88af..770426b48db 100644
--- a/source/gameengine/Physics/common/PHY_IPhysicsController.h
+++ b/source/gameengine/Physics/common/PHY_IPhysicsController.h
@@ -90,6 +90,12 @@ class PHY_IPhysicsController : public PHY_IController
 		virtual float GetMargin() const=0;
 		virtual float GetRadius() const=0;
 		virtual void  SetRadius(float margin) = 0;
+
+		virtual float GetLinVelocityMin() const=0;
+		virtual void  SetLinVelocityMin(float val) = 0;
+		virtual float GetLinVelocityMax() const=0;
+		virtual void  SetLinVelocityMax(float val) = 0;
+		
 		PHY__Vector3	GetWorldPosition(PHY__Vector3& localpos);
 
 };
diff --git a/source/gameengine/Physics/common/PHY_Pro.h b/source/gameengine/Physics/common/PHY_Pro.h
index 32e63ac2f6d..0249fc3118a 100644
--- a/source/gameengine/Physics/common/PHY_Pro.h
+++ b/source/gameengine/Physics/common/PHY_Pro.h
@@ -35,9 +35,11 @@
 struct PHY_ShapeProps {
 	MT_Scalar  m_mass;                  // Total mass
 	MT_Scalar  m_inertia;               // Inertia, should be a tensor some time 
-	MT_Scalar  m_lin_drag;              // Linear drag (air, water) 0 = concrete, 1 = vacuum 
-	MT_Scalar  m_ang_drag;              // Angular drag
+	MT_Scalar  m_lin_drag;              // Linear drag (air, water) 0 = concrete, 1 = vacuum, inverted and called dampening in blenders UI
+	MT_Scalar  m_ang_drag;              // Angular drag, inverted and called dampening in blenders UI
 	MT_Scalar  m_friction_scaling[3];   // Scaling for anisotropic friction. Component in range [0, 1]   
+	MT_Scalar  m_clamp_vel_min;			// Clamp the minimum velocity, this ensures an object moves at a minimum speed unless its stationary
+	MT_Scalar  m_clamp_vel_max;			// Clamp max velocity
 	bool       m_do_anisotropic;        // Should I do anisotropic friction? 
 	bool       m_do_fh;                 // Should the object have a linear Fh spring?
 	bool       m_do_rot_fh;             // Should the object have an angular Fh spring?
diff --git a/source/gameengine/PyDoc/KX_GameObject.py b/source/gameengine/PyDoc/KX_GameObject.py
index fa4641c3e2f..44b84d44d8d 100644
--- a/source/gameengine/PyDoc/KX_GameObject.py
+++ b/source/gameengine/PyDoc/KX_GameObject.py
@@ -16,8 +16,18 @@ class KX_GameObject: # (SCA_IObject)
 	@ivar name: The object's name. (Read only)
 		- note: Currently (Blender 2.49) the prefix "OB" is added to all objects name. This may change in blender 2.5.
 	@type name: string.
-	@ivar mass: The object's mass (provided the object has a physics controller).
+	@ivar mass: The object's mass
+		- note: The object must have a physics controller for the mass to be applied, otherwise the mass value will be returned as 0.0
 	@type mass: float
+	@ivar linVelocityMin: Enforces the object keeps moving at a minimum velocity.
+		- note: Applies to dynamic and rigid body objects only.
+		- note: A value of 0.0 disables this option.
+		- note: While objects are stationary the minimum velocity will not be applied.
+	@type linVelocityMin: float
+	@ivar linVelocityMax: Clamp the maximum linear velocity to prevent objects moving beyond a set speed.
+		- note: Applies to dynamic and rigid body objects only.
+		- note: A value of 0.0 disables this option (rather then setting it stationary).
+	@type linVelocityMax: float
 	@ivar localInertia: the object's inertia vector in local coordinates. Read only.
 	@type localInertia: list [ix, iy, iz]
 	@ivar parent: The object's parent object. (Read only)
@@ -35,7 +45,7 @@ class KX_GameObject: # (SCA_IObject)
 	@type scaling: list [sx, sy, sz]
 	@ivar timeOffset: adjust the slowparent delay at runtime.
 	@type timeOffset: float
-	@ivar state: the game object's state bitmask.
+	@ivar state: the game object's state bitmask, using the first 30 bits, one bit must always be set.
 	@type state: int
 	@ivar meshes: a list meshes for this object.
 		- note: Most objects use only 1 mesh.