@ -17,10 +17,13 @@
# include "actor.hpp"
# include "collisiontype.hpp"
# include "constants.hpp"
# include "contacttestwrapper.h"
# include "physicssystem.hpp"
# include "stepper.hpp"
# include "trace.h"
# include <cmath>
namespace MWPhysics
{
static bool isActor ( const btCollisionObject * obj )
@ -29,12 +32,50 @@ namespace MWPhysics
return obj - > getBroadphaseHandle ( ) - > m_collisionFilterGroup = = CollisionType_Actor ;
}
template < class Vec3 >
static bool isWalkableSlope ( const Vec3 & normal )
class ContactCollectionCallback : public btCollisionWorld : : ContactResultCallback
{
static const float sMaxSlopeCos = std : : cos ( osg : : DegreesToRadians ( sMaxSlope ) ) ;
return ( normal . z ( ) > sMaxSlopeCos ) ;
}
public :
ContactCollectionCallback ( const btCollisionObject * me , osg : : Vec3f velocity ) : mMe ( me )
{
m_collisionFilterGroup = me - > getBroadphaseHandle ( ) - > m_collisionFilterGroup ;
m_collisionFilterMask = me - > getBroadphaseHandle ( ) - > m_collisionFilterMask & ~ CollisionType_Projectile ;
mVelocity = Misc : : Convert : : toBullet ( velocity ) ;
}
btScalar addSingleResult ( btManifoldPoint & contact , const btCollisionObjectWrapper * colObj0Wrap , int partId0 , int index0 , const btCollisionObjectWrapper * colObj1Wrap , int partId1 , int index1 ) override
{
if ( isActor ( colObj0Wrap - > getCollisionObject ( ) ) & & isActor ( colObj1Wrap - > getCollisionObject ( ) ) )
return 0.0 ;
// ignore overlap if we're moving in the same direction as it would push us out (don't change this to >=, that would break detection when not moving)
if ( contact . m_normalWorldOnB . dot ( mVelocity ) > 0.0 )
return 0.0 ;
auto delta = contact . m_normalWorldOnB * - contact . m_distance1 ;
mContactSum + = delta ;
mMaxX = std : : max ( std : : abs ( delta . x ( ) ) , mMaxX ) ;
mMaxY = std : : max ( std : : abs ( delta . y ( ) ) , mMaxY ) ;
mMaxZ = std : : max ( std : : abs ( delta . z ( ) ) , mMaxZ ) ;
if ( contact . m_distance1 < mDistance )
{
mDistance = contact . m_distance1 ;
mNormal = contact . m_normalWorldOnB ;
mDelta = delta ;
return mDistance ;
}
else
{
return 0.0 ;
}
}
btScalar mMaxX = 0.0 ;
btScalar mMaxY = 0.0 ;
btScalar mMaxZ = 0.0 ;
btVector3 mContactSum { 0.0 , 0.0 , 0.0 } ;
btVector3 mNormal { 0.0 , 0.0 , 0.0 } ; // points towards "me"
btVector3 mDelta { 0.0 , 0.0 , 0.0 } ; // points towards "me"
btScalar mDistance = 0.0 ; // negative or zero
protected :
btVector3 mVelocity ;
const btCollisionObject * mMe ;
} ;
osg : : Vec3f MovementSolver : : traceDown ( const MWWorld : : Ptr & ptr , const osg : : Vec3f & position , Actor * actor , btCollisionWorld * collisionWorld , float maxHeight )
{
@ -99,13 +140,13 @@ namespace MWPhysics
}
const btCollisionObject * colobj = physicActor - > getCollisionObject ( ) ;
osg : : Vec3f halfExtents = physicActor - > getHalfExtents ( ) ;
// NOTE: here we don't account for the collision box translation (i.e. physicActor->getPosition() - refpos.pos).
// That means the collision shape used for moving this actor is in a different spot than the collision shape
// other actors are using to collide against this actor.
// While this is strictly speaking wrong, it's needed for MW compatibility.
actor . mPosition . z ( ) + = halfExtents . z ( ) ;
// Adjust for collision mesh offset relative to actor's "location"
// (doTrace doesn't take local/interior collision shape translation into account, so we have to do it on our own)
// for compatibility with vanilla assets, we have to derive this from the vertical half extent instead of from internal hull translation
// if not for this hack, the "correct" collision hull position would be physicActor->getScaledMeshTranslation()
osg : : Vec3f halfExtents = physicActor - > getHalfExtents ( ) ;
actor . mPosition . z ( ) + = halfExtents . z ( ) ; // vanilla-accurate
static const float fSwimHeightScale = MWBase : : Environment : : get ( ) . getWorld ( ) - > getStore ( ) . get < ESM : : GameSetting > ( ) . find ( " fSwimHeightScale " ) - > mValue . getFloat ( ) ;
float swimlevel = actor . mWaterlevel + halfExtents . z ( ) - ( physicActor - > getRenderingHalfExtents ( ) . z ( ) * 2 * fSwimHeightScale ) ;
@ -156,6 +197,13 @@ namespace MWPhysics
* The initial velocity was set earlier ( see above ) .
*/
float remainingTime = time ;
bool seenGround = physicActor - > getOnGround ( ) & & ! physicActor - > getOnSlope ( ) & & ! actor . mFlying ;
int numTimesSlid = 0 ;
osg : : Vec3f lastSlideNormal ( 0 , 0 , 1 ) ;
osg : : Vec3f lastSlideNormalFallback ( 0 , 0 , 1 ) ;
bool forceGroundTest = false ;
for ( int iterations = 0 ; iterations < sMaxIterations & & remainingTime > 0.01f ; + + iterations )
{
osg : : Vec3f nextpos = newPosition + velocity * remainingTime ;
@ -164,7 +212,7 @@ namespace MWPhysics
if ( ! actor . mFlying & & nextpos . z ( ) > swimlevel & & newPosition . z ( ) < swimlevel )
{
const osg : : Vec3f down ( 0 , 0 , - 1 ) ;
velocity = slide ( velocity , down ) ;
velocity = reject ( velocity , down ) ;
// NOTE: remainingTime is unchanged before the loop continues
continue ; // velocity updated, calculate nextpos again
}
@ -193,92 +241,158 @@ namespace MWPhysics
break ;
}
// We are touching something.
if ( tracer . mFraction < 1E-9 f )
{
// Try to separate by backing off slighly to unstuck the solver
osg : : Vec3f backOff = ( newPosition - tracer . mHitPoint ) * 1E-2 f ;
newPosition + = backOff ;
}
if ( isWalkableSlope ( tracer . mPlaneNormal ) & & ! actor . mFlying & & newPosition . z ( ) > = swimlevel )
seenGround = true ;
// We hit something. Check if we can step up.
float hitHeight = tracer . mHitPoint . z ( ) - tracer . mEndPos . z ( ) + halfExtents . z ( ) ;
osg : : Vec3f oldPosition = newPosition ;
bool result = false ;
bool usedStepLogic = false ;
if ( hitHeight < sStepSizeUp & & ! isActor ( tracer . mHitObject ) )
{
// Try to step up onto it.
// NOTE: stepMove does not allow stepping over, modifies newPositio n if successful
result = stepper . step ( newPosition , velocity * remainingTime , remainingTime ) ;
// NOTE: this modifies newPosition and velocity on its ow n if successful
usedStepLogic = stepper . step ( newPosition , velocity , remainingTime , seenGround , iterations = = 0 ) ;
}
if ( result )
if ( usedStepLogic )
{
// don't let pure water creatures move out of water after stepMove
const auto ptr = physicActor - > getPtr ( ) ;
if ( ptr . getClass ( ) . isPureWaterCreature ( ptr ) & & newPosition . z ( ) + halfExtents . z ( ) > actor . mWaterlevel )
newPosition = oldPosition ;
else if ( ! actor . mFlying & & actor . mPosition . z ( ) > = swimlevel )
forceGroundTest = true ;
}
else
{
// Can't move this way, try to find another spot along the plane
osg : : Vec3f newVelocity = slide ( velocity , tracer . mPlaneNormal ) ;
// Can't step up, so slide against what we ran into
remainingTime * = ( 1.0f - tracer . mFraction ) ;
auto planeNormal = tracer . mPlaneNormal ;
// If we touched the ground this frame, and whatever we ran into is a wall of some sort,
// pretend that its collision normal is pointing horizontally
// (fixes snagging on slightly downward-facing walls, and crawling up the bases of very steep walls because of the collision margin)
if ( seenGround & & ! isWalkableSlope ( planeNormal ) & & planeNormal . z ( ) ! = 0 )
{
planeNormal . z ( ) = 0 ;
planeNormal . normalize ( ) ;
}
// Move up to what we ran into (with a bit of a collision margin)
if ( ( newPosition - tracer . mEndPos ) . length2 ( ) > sCollisionMargin * sCollisionMargin )
{
auto direction = velocity ;
direction . normalize ( ) ;
newPosition = tracer . mEndPos ;
newPosition - = direction * sCollisionMargin ;
}
osg : : Vec3f newVelocity = ( velocity * planeNormal < = 0.0 ) ? reject ( velocity , planeNormal ) : velocity ;
bool usedSeamLogic = false ;
// check for the current and previous collision planes forming an acute angle; slide along the seam if they do
if ( numTimesSlid > 0 )
{
auto dotA = lastSlideNormal * planeNormal ;
auto dotB = lastSlideNormalFallback * planeNormal ;
if ( numTimesSlid < = 1 ) // ignore fallback normal if this is only the first or second slide
dotB = 1.0 ;
if ( dotA < = 0.0 | | dotB < = 0.0 )
{
osg : : Vec3f bestNormal = lastSlideNormal ;
// use previous-to-previous collision plane if it's acute with current plane but actual previous plane isn't
if ( dotB < dotA )
{
bestNormal = lastSlideNormalFallback ;
lastSlideNormal = lastSlideNormalFallback ;
}
auto constraintVector = bestNormal ^ planeNormal ; // cross product
if ( constraintVector . length2 ( ) > 0 ) // only if it's not zero length
{
constraintVector . normalize ( ) ;
newVelocity = project ( velocity , constraintVector ) ;
// version of surface rejection for acute crevices/seams
auto averageNormal = bestNormal + planeNormal ;
averageNormal . normalize ( ) ;
tracer . doTrace ( colobj , newPosition , newPosition + averageNormal * ( sCollisionMargin * 2.0 ) , collisionWorld ) ;
newPosition = ( newPosition + tracer . mEndPos ) / 2.0 ;
usedSeamLogic = true ;
}
}
}
// otherwise just keep the normal vector rejection
// if this isn't the first iteration, or if the first iteration is also the last iteration,
// move away from the collision plane slightly, if possible
// this reduces getting stuck in some concave geometry, like the gaps above the railings in some ald'ruhn buildings
// this is different from the normal collision margin, because the normal collision margin is along the movement path,
// but this is along the collision normal
if ( ! usedSeamLogic & & ( iterations > 0 | | remainingTime < 0.01f ) )
{
tracer . doTrace ( colobj , newPosition , newPosition + planeNormal * ( sCollisionMargin * 2.0 ) , collisionWorld ) ;
newPosition = ( newPosition + tracer . mEndPos ) / 2.0 ;
}
// Do not allow sliding upward if there is gravity.
// Stepping will have taken care of that.
if ( ! ( newPosition . z ( ) < swimlevel | | actor . mFlying ) )
newVelocity . z ( ) = std : : min ( newVelocity . z ( ) , 0.0f ) ;
// Do not allow sliding up steep slopes if there is gravity.
if ( newPosition . z ( ) > = swimlevel & & ! actor . mFlying & & ! isWalkableSlope ( planeNormal ) )
newVelocity . z ( ) = std : : min ( newVelocity . z ( ) , velocity . z ( ) ) ;
if ( ( newVelocity - velocity ) . length2 ( ) < 0.01 )
if ( newVelocity * origVelocity < = 0.0f )
break ;
if ( ( newVelocity * origVelocity ) < = 0.f )
break ; // ^ dot product
numTimesSlid + = 1 ;
lastSlideNormalFallback = lastSlideNormal ;
lastSlideNormal = planeNormal ;
velocity = newVelocity ;
}
}
bool isOnGround = false ;
bool isOnSlope = false ;
if ( ! ( inertia . z ( ) > 0.f ) & & ! ( newPosition . z ( ) < swimlevel ) )
if ( forceGroundTest | | ( inertia . z ( ) < = 0.f & & newPosition . z ( ) > = swimlevel ) )
{
osg : : Vec3f from = newPosition ;
osg : : Vec3f to = newPosition - ( physicActor - > getOnGround ( ) ? osg : : Vec3f ( 0 , 0 , sStepSizeDown + 2 * sGroundOffset ) : osg : : Vec3f ( 0 , 0 , 2 * sGroundOffset ) ) ;
auto dropDistance = 2 * sGroundOffset + ( physicActor - > getOnGround ( ) ? sStepSizeDown : 0 ) ;
osg : : Vec3f to = newPosition - osg : : Vec3f ( 0 , 0 , dropDistance ) ;
tracer . doTrace ( colobj , from , to , collisionWorld ) ;
if ( tracer . mFraction < 1.0f & & ! isActor ( tracer . mHitObject ) )
if ( tracer . mFraction < 1.0f )
{
const btCollisionObject * standingOn = tracer . mHitObject ;
PtrHolder * ptrHolder = static_cast < PtrHolder * > ( standingOn - > getUserPointer ( ) ) ;
if ( ptrHolder )
actor . mStandingOn = ptrHolder - > getPtr ( ) ;
if ( standingOn - > getBroadphaseHandle ( ) - > m_collisionFilterGroup = = CollisionType_Water )
physicActor - > setWalkingOnWater ( true ) ;
if ( ! actor . mFlying )
newPosition . z ( ) = tracer . mEndPos . z ( ) + sGroundOffset ;
if ( ! isActor ( tracer . mHitObject ) )
{
isOnGround = true ;
isOnSlope = ! isWalkableSlope ( tracer . mPlaneNormal ) ;
isOnGround = true ;
const btCollisionObject * standingOn = tracer . mHitObject ;
PtrHolder * ptrHolder = static_cast < PtrHolder * > ( standingOn - > getUserPointer ( ) ) ;
if ( ptrHolder )
actor . mStandingOn = ptrHolder - > getPtr ( ) ;
isOnSlope = ! isWalkableSlope ( tracer . mPlaneNormal ) ;
}
else
{
// standing on actors is not allowed (see above).
// in addition to that, apply a sliding effect away from the center of the actor,
// so that we do not stay suspended in air indefinitely.
if ( tracer . mFraction < 1.0f & & isActor ( tracer . mHitObject ) )
{
if ( osg : : Vec3f ( velocity . x ( ) , velocity . y ( ) , 0 ) . length2 ( ) < 100.f * 100.f )
if ( standingOn - > getBroadphaseHandle ( ) - > m_collisionFilterGroup = = CollisionType_Water )
physicActor - > setWalkingOnWater ( true ) ;
if ( ! actor . mFlying & & ! isOnSlope )
{
btVector3 aabbMin , aabbMax ;
tracer . mHitObject - > getCollisionShape ( ) - > getAabb ( tracer . mHitObject - > getWorldTransform ( ) , aabbMin , aabbMax ) ;
btVector3 center = ( aabbMin + aabbMax ) / 2.f ;
inertia = osg : : Vec3f ( actor . mPosition . x ( ) - center . x ( ) , actor . mPosition . y ( ) - center . y ( ) , 0 ) ;
inertia . normalize ( ) ;
inertia * = 100 ;
if ( tracer . mFraction * dropDistance > sGroundOffset )
newPosition . z ( ) = tracer . mEndPos . z ( ) + sGroundOffset ;
else
{
newPosition . z ( ) = tracer . mEndPos . z ( ) ;
tracer . doTrace ( colobj , newPosition , newPosition + osg : : Vec3f ( 0 , 0 , 2 * sGroundOffset ) , collisionWorld ) ;
newPosition = ( newPosition + tracer . mEndPos ) / 2.0 ;
}
}
}
else
{
// Vanilla allows actors to float on top of other actors. Do not push them off.
if ( ! actor . mFlying & & isWalkableSlope ( tracer . mPlaneNormal ) & & tracer . mEndPos . z ( ) + sGroundOffset < = newPosition . z ( ) )
newPosition . z ( ) = tracer . mEndPos . z ( ) + sGroundOffset ;
isOnGround = false ;
isOnGround = false ;
}
}
}
@ -298,7 +412,98 @@ namespace MWPhysics
physicActor - > setOnGround ( isOnGround ) ;
physicActor - > setOnSlope ( isOnSlope ) ;
newPosition . z ( ) - = halfExtents . z ( ) ; // remove what was added at the beginning
actor . mPosition = newPosition ;
// remove what was added earlier in compensating for doTrace not taking interior transformation into account
actor . mPosition . z ( ) - = halfExtents . z ( ) ; // vanilla-accurate
}
btVector3 addMarginToDelta ( btVector3 delta )
{
if ( delta . length2 ( ) = = 0.0 )
return delta ;
return delta + delta . normalized ( ) * sCollisionMargin ;
}
void MovementSolver : : unstuck ( ActorFrameData & actor , const btCollisionWorld * collisionWorld )
{
const auto & ptr = actor . mActorRaw - > getPtr ( ) ;
if ( ! ptr . getClass ( ) . isMobile ( ptr ) )
return ;
auto * physicActor = actor . mActorRaw ;
if ( ! physicActor - > getCollisionMode ( ) ) // noclipping/tcl
return ;
auto * collisionObject = physicActor - > getCollisionObject ( ) ;
auto tempPosition = actor . mPosition ;
// use vanilla-accurate collision hull position hack (do same hitbox offset hack as movement solver)
// if vanilla compatibility didn't matter, the "correct" collision hull position would be physicActor->getScaledMeshTranslation()
const auto verticalHalfExtent = osg : : Vec3f ( 0.0 , 0.0 , physicActor - > getHalfExtents ( ) . z ( ) ) ;
// use a 3d approximation of the movement vector to better judge player intent
const ESM : : Position & refpos = ptr . getRefData ( ) . getPosition ( ) ;
auto velocity = ( osg : : Quat ( refpos . rot [ 0 ] , osg : : Vec3f ( - 1 , 0 , 0 ) ) * osg : : Quat ( refpos . rot [ 2 ] , osg : : Vec3f ( 0 , 0 , - 1 ) ) ) * actor . mMovement ;
// try to pop outside of the world before doing anything else if we're inside of it
if ( ! physicActor - > getOnGround ( ) | | physicActor - > getOnSlope ( ) )
velocity + = physicActor - > getInertialForce ( ) ;
// because of the internal collision box offset hack, and the fact that we're moving the collision box manually,
// we need to replicate part of the collision box's transform process from scratch
osg : : Vec3f refPosition = tempPosition + verticalHalfExtent ;
osg : : Vec3f goodPosition = refPosition ;
const btTransform oldTransform = collisionObject - > getWorldTransform ( ) ;
btTransform newTransform = oldTransform ;
auto gatherContacts = [ & ] ( btVector3 newOffset ) - > ContactCollectionCallback
{
goodPosition = refPosition + Misc : : Convert : : toOsg ( addMarginToDelta ( newOffset ) ) ;
newTransform . setOrigin ( Misc : : Convert : : toBullet ( goodPosition ) ) ;
collisionObject - > setWorldTransform ( newTransform ) ;
ContactCollectionCallback callback { collisionObject , velocity } ;
ContactTestWrapper : : contactTest ( const_cast < btCollisionWorld * > ( collisionWorld ) , collisionObject , callback ) ;
return callback ;
} ;
// check whether we're inside the world with our collision box with manually-derived offset
auto contactCallback = gatherContacts ( { 0.0 , 0.0 , 0.0 } ) ;
if ( contactCallback . mDistance < - sAllowedPenetration )
{
// we are; try moving it out of the world
auto positionDelta = contactCallback . mContactSum ;
// limit rejection delta to the largest known individual rejections
if ( std : : abs ( positionDelta . x ( ) ) > contactCallback . mMaxX )
positionDelta * = contactCallback . mMaxX / std : : abs ( positionDelta . x ( ) ) ;
if ( std : : abs ( positionDelta . y ( ) ) > contactCallback . mMaxY )
positionDelta * = contactCallback . mMaxY / std : : abs ( positionDelta . y ( ) ) ;
if ( std : : abs ( positionDelta . z ( ) ) > contactCallback . mMaxZ )
positionDelta * = contactCallback . mMaxZ / std : : abs ( positionDelta . z ( ) ) ;
auto contactCallback2 = gatherContacts ( positionDelta ) ;
// successfully moved further out from contact (does not have to be in open space, just less inside of things)
if ( contactCallback2 . mDistance > contactCallback . mDistance )
tempPosition = goodPosition - verticalHalfExtent ;
// try again but only upwards (fixes some bad coc floors)
else
{
// upwards-only offset
auto contactCallback3 = gatherContacts ( { 0.0 , 0.0 , std : : abs ( positionDelta . z ( ) ) } ) ;
// success
if ( contactCallback3 . mDistance > contactCallback . mDistance )
tempPosition = goodPosition - verticalHalfExtent ;
else
// try again but fixed distance up
{
auto contactCallback4 = gatherContacts ( { 0.0 , 0.0 , 10.0 } ) ;
// success
if ( contactCallback4 . mDistance > contactCallback . mDistance )
tempPosition = goodPosition - verticalHalfExtent ;
}
}
}
collisionObject - > setWorldTransform ( oldTransform ) ;
actor . mPosition = tempPosition ;
}
}
AnyOldName3
4 years ago