BGE: added clamping of angular velocity.

Angular velocity clamping was missing from the BGE. It is implemented
similarly to the linear velocity clamping. It is needed to be able to
drive physical simulations of systems that have a limited rotational
speed.

Reviewed by: campbellbarton, panzergame, ton

Differential Revision: https://developer.blender.org/D1365

5 files changed, 41 insertions, 0 deletions

diff --git a/source/gameengine/Physics/Bullet/CcdPhysicsController.cpp b/source/gameengine/Physics/Bullet/CcdPhysicsController.cpp
index 4306d6d0cd7..692704b5080 100644
--- a/source/gameengine/Physics/Bullet/CcdPhysicsController.cpp
+++ b/source/gameengine/Physics/Bullet/CcdPhysicsController.cpp
@@ -713,6 +713,17 @@ void CcdPhysicsController::SimulationTick(float timestep)
 		else if (m_cci.m_clamp_vel_min > 0.0f && !btFuzzyZero(len) && len < m_cci.m_clamp_vel_min)
 			body->setLinearVelocity(linvel * (m_cci.m_clamp_vel_min / len));
 	}
+
+	// Clamp angular velocity
+	if (m_cci.m_clamp_angvel_max > 0.0f || m_cci.m_clamp_angvel_min > 0.0f) {
+		const btVector3 &angvel = body->getAngularVelocity();
+		btScalar len = angvel.length();
+
+		if (m_cci.m_clamp_angvel_max > 0.0f && len > m_cci.m_clamp_angvel_max)
+			body->setAngularVelocity(angvel * (m_cci.m_clamp_angvel_max / len));
+		else if (m_cci.m_clamp_angvel_min > 0.0f && !btFuzzyZero(len) && len < m_cci.m_clamp_angvel_min)
+			body->setAngularVelocity(angvel * (m_cci.m_clamp_angvel_min / len));
+	}
 }
 
 
diff --git a/source/gameengine/Physics/Bullet/CcdPhysicsController.h b/source/gameengine/Physics/Bullet/CcdPhysicsController.h
index 2a15b6136e4..c49ae8d20e1 100644
--- a/source/gameengine/Physics/Bullet/CcdPhysicsController.h
+++ b/source/gameengine/Physics/Bullet/CcdPhysicsController.h
@@ -236,6 +236,8 @@ struct CcdConstructionInfo
 		m_mass(0.f),
 		m_clamp_vel_min(-1.f),
 		m_clamp_vel_max(-1.f),
+	    m_clamp_angvel_min(0.0f),
+	    m_clamp_angvel_max(0.0f),
 		m_restitution(0.1f),
 		m_friction(0.5f),
 		m_linearDamping(0.1f),
@@ -302,6 +304,8 @@ struct CcdConstructionInfo
 	btScalar	m_mass;
 	btScalar	m_clamp_vel_min;  
 	btScalar	m_clamp_vel_max;  
+	btScalar	m_clamp_angvel_min;  // Minimum angular velocity, in radians/sec.
+	btScalar	m_clamp_angvel_max;  // Maximum angular velocity, in radians/sec.
 	btScalar	m_restitution;
 	btScalar	m_friction;
 	btScalar	m_linearDamping;
@@ -708,6 +712,23 @@ protected:
 			return m_cci.m_clamp_vel_max;
 		}
 
+		virtual void SetAngularVelocityMin(float val)
+		{
+			m_cci.m_clamp_angvel_min = val;
+		}
+		virtual float GetAngularVelocityMin() const
+		{
+			return m_cci.m_clamp_angvel_min;
+		}
+		virtual void SetAngularVelocityMax(float val)
+		{
+			m_cci.m_clamp_angvel_max = val;
+		}
+		virtual float GetAngularVelocityMax() const
+		{
+			return m_cci.m_clamp_angvel_max;
+		}
+
 		bool	WantsSleeping();
 
 		void	UpdateDeactivation(float timeStep);
diff --git a/source/gameengine/Physics/Bullet/CcdPhysicsEnvironment.cpp b/source/gameengine/Physics/Bullet/CcdPhysicsEnvironment.cpp
index 14a19fdfb41..82451e6a3ed 100644
--- a/source/gameengine/Physics/Bullet/CcdPhysicsEnvironment.cpp
+++ b/source/gameengine/Physics/Bullet/CcdPhysicsEnvironment.cpp
@@ -3111,6 +3111,8 @@ void CcdPhysicsEnvironment::ConvertObject(KX_GameObject *gameobj, RAS_MeshObject
 	ci.m_mass = isbulletdyna ? 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_clamp_angvel_min = shapeprops->m_clamp_angvel_min;
+	ci.m_clamp_angvel_max = shapeprops->m_clamp_angvel_max;
 	ci.m_stepHeight = isbulletchar ? shapeprops->m_step_height : 0.f;
 	ci.m_jumpSpeed = isbulletchar ? shapeprops->m_jump_speed : 0.f;
 	ci.m_fallSpeed = isbulletchar ? shapeprops->m_fall_speed : 0.f;
diff --git a/source/gameengine/Physics/common/PHY_IPhysicsController.h b/source/gameengine/Physics/common/PHY_IPhysicsController.h
index 3e2337f01ea..62b163536dd 100644
--- a/source/gameengine/Physics/common/PHY_IPhysicsController.h
+++ b/source/gameengine/Physics/common/PHY_IPhysicsController.h
@@ -125,6 +125,11 @@ class PHY_IPhysicsController : public PHY_IController
 		virtual float GetLinVelocityMax() const=0;
 		virtual void  SetLinVelocityMax(float val) = 0;
 		
+		virtual void SetAngularVelocityMin(float val) = 0;
+		virtual float GetAngularVelocityMin() const = 0;
+		virtual void SetAngularVelocityMax(float val) = 0;
+		virtual float GetAngularVelocityMax() const = 0;
+
 		MT_Vector3	GetWorldPosition(MT_Vector3& localpos);
 
 		// Shape control
diff --git a/source/gameengine/Physics/common/PHY_Pro.h b/source/gameengine/Physics/common/PHY_Pro.h
index 7c5d9c9638e..c9b91b06a3c 100644
--- a/source/gameengine/Physics/common/PHY_Pro.h
+++ b/source/gameengine/Physics/common/PHY_Pro.h
@@ -43,6 +43,8 @@ struct PHY_ShapeProps {
 	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
+	MT_Scalar  m_clamp_angvel_min;		// Clamp the minimum angular velocity.
+	MT_Scalar  m_clamp_angvel_max;		// Clamp the maximum angular 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?