BGE patch #28476: Character object physics type

===============================================
This patch adds a new "Character" BGE physics type which uses Bullet's btKinematicCharacter for simulation instead of full-blown dynamics. It is appropiate for (player-controlled) characters, for which the other physics types often result unexpected results (bouncing off walls, sliding etc.) and for which simple kinematics offers much more precision.

"Character" can be chosen like any other physics type in the "Physics" section of the properties window. Current settings for tweaking are "Step Height" (to make the object automatically climb small steps if it collides with them), "Fall Speed" (the maximum speed that the object can have when falling) and "Jump Speed", which is currently not used.

See http://projects.blender.org/tracker/?func=detail&atid=127&aid=28476&group_id=9
for sample blends and a discussion on the patch: how to use it and what influences the behavior of the character object.

Known problem: there is a crash if the "compound" option is set in the physics panel of the Character object.

1 files changed, 10 insertions, 2 deletions

diff --git a/source/gameengine/Ketsji/KX_ConvertPhysicsObjects.cpp b/source/gameengine/Ketsji/KX_ConvertPhysicsObjects.cpp
index e0e8e2d9b3f..227ca39281f 100644
--- a/source/gameengine/Ketsji/KX_ConvertPhysicsObjects.cpp
+++ b/source/gameengine/Ketsji/KX_ConvertPhysicsObjects.cpp
@@ -100,6 +100,7 @@ void	KX_ConvertBulletObject(	class	KX_GameObject* gameobj,
 
 	bool isbulletdyna = false;
 	bool isbulletsensor = false;
+	bool isbulletchar = false;
 	bool useGimpact = false;
 	CcdConstructionInfo ci;
 	class PHY_IMotionState* motionstate = new KX_MotionState(gameobj->GetSGNode());
@@ -122,9 +123,13 @@ void	KX_ConvertBulletObject(	class	KX_GameObject* gameobj,
 	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;
+	ci.m_stepHeight = objprop->m_character ? shapeprops->m_step_height : 0.f;
+	ci.m_jumpSpeed = objprop->m_character ? shapeprops->m_jump_speed : 0.f;
+	ci.m_fallSpeed = objprop->m_character ? shapeprops->m_fall_speed : 0.f;
 	shapeInfo->m_radius = objprop->m_radius;
 	isbulletdyna = objprop->m_dyna;
 	isbulletsensor = objprop->m_sensor;
+	isbulletchar = objprop->m_character;
 	useGimpact = ((isbulletdyna || isbulletsensor) && !objprop->m_softbody);
 
 	ci.m_localInertiaTensor = btVector3(ci.m_mass/3.f,ci.m_mass/3.f,ci.m_mass/3.f);
@@ -400,21 +405,24 @@ void	KX_ConvertBulletObject(	class	KX_GameObject* gameobj,
 	////////////////////
 	ci.m_collisionFilterGroup = 
 		(isbulletsensor) ? short(CcdConstructionInfo::SensorFilter) :
-		(isbulletdyna) ? short(CcdConstructionInfo::DefaultFilter) : 
+		(isbulletdyna) ? short(CcdConstructionInfo::DefaultFilter) :
+		(isbulletchar) ? short(CcdConstructionInfo::CharacterFilter) : 
 		short(CcdConstructionInfo::StaticFilter);
 	ci.m_collisionFilterMask = 
 		(isbulletsensor) ? short(CcdConstructionInfo::AllFilter ^ CcdConstructionInfo::SensorFilter) :
 		(isbulletdyna) ? short(CcdConstructionInfo::AllFilter) : 
+		(isbulletchar) ? short(CcdConstructionInfo::AllFilter) :
 		short(CcdConstructionInfo::AllFilter ^ CcdConstructionInfo::StaticFilter);
 	ci.m_bRigid = objprop->m_dyna && objprop->m_angular_rigidbody;
 	
 	ci.m_contactProcessingThreshold = objprop->m_contactProcessingThreshold;//todo: expose this in advanced settings, just like margin, default to 10000 or so
 	ci.m_bSoft = objprop->m_softbody;
 	ci.m_bSensor = isbulletsensor;
+	ci.m_bCharacter = isbulletchar;
 	ci.m_bGimpact = useGimpact;
 	MT_Vector3 scaling = gameobj->NodeGetWorldScaling();
 	ci.m_scaling.setValue(scaling[0], scaling[1], scaling[2]);
-	KX_BulletPhysicsController* physicscontroller = new KX_BulletPhysicsController(ci,isbulletdyna,isbulletsensor,objprop->m_hasCompoundChildren);
+	KX_BulletPhysicsController* physicscontroller = new KX_BulletPhysicsController(ci,isbulletdyna,isbulletsensor,isbulletchar,objprop->m_hasCompoundChildren);
 	// shapeInfo is reference counted, decrement now as we don't use it anymore
 	if (shapeInfo)
 		shapeInfo->Release();