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Merged
sunzenshen merged 1 commit into from
Oct 17, 2026
Merged

Bots step off a ladder crouched through a crawl gap #2232

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119 changes: 117 additions & 2 deletions src/game/server/neo/bot/behavior/neo_bot_ladder_climb.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -17,7 +17,7 @@ static constexpr float LADDER_PLACE_SEEK = 16.0f;
//---------------------------------------------------------------------------------------------
CNEOBotLadderClimb::CNEOBotLadderClimb( const CNavLadder *ladder, bool goingUp )
: m_ladder( ladder ), m_bGoingUp( goingUp ), m_flLastZ( 0.0f ),
m_bDismountPhase( false ), m_bJumpedOffLadder( false ), m_pExitArea( nullptr ), m_nNudges( 0 )
m_bDismountPhase( false ), m_bJumpedOffLadder( false ), m_bCrawlDismount( false ), m_bCrawlPushed( false ), m_pExitArea( nullptr ), m_nNudges( 0 )
{
m_dismountPos = vec3_origin;
m_ladderForward = ladder ? -ladder->GetNormal() : vec3_origin;
Expand Down Expand Up @@ -355,7 +355,8 @@ ActionResult<CNEOBot> CNEOBotLadderClimb::Update( CNEOBot *me, float /*interval*

if ( !onLadder )
{
if ( mover->IsOnGround() )
// crawling off, the gap's sill is ground too, short of the landing
if ( mover->IsOnGround() && !m_bCrawlDismount )
{
return Done( "Reached the ground, ending climb" );
}
Expand Down Expand Up @@ -472,6 +473,20 @@ ActionResult<CNEOBot> CNEOBotLadderClimb::Update( CNEOBot *me, float /*interval*
bWantsDismount = true;
}

// A gap at the top only a crouched body fits through, such as a vent or a low window: climbing on never clears it,
// so duck on the way up, and step off crouched once the gap is in reach
if ( m_bGoingUp && onLadder && m_pExitArea && currentZ > GetCrawlFeetZ() - CRAWL_DUCK_RANGE && IsCrawlOnlyExit( me, toExit ) )
{
me->PressCrouchButton( CRAWL_CROUCH_HOLD );
if ( ( me->GetFlags() & FL_DUCKING ) && fabsf( GetCrawlFeetZ() - currentZ ) <= CRAWL_SNAP_DIST )
{
m_bCrawlDismount = true;
EnterDismountPhase( me );
UpdateCrawlDismount( me, toExit, onLadder );
return Continue();
}
}

// A parapet between the ladder and a roof exit blocks the step off at floor height:
// keep climbing until the hull clears it (stuck detection ends it if nothing does)
const bool bLipInTheWay = bWantsDismount && m_bGoingUp && onLadder
Expand Down Expand Up @@ -562,6 +577,12 @@ ActionResult<CNEOBot> CNEOBotLadderClimb::Update( CNEOBot *me, float /*interval*
return Done( "Dismount walk timed out" );
}

if ( m_bCrawlDismount && m_pExitArea )
{
UpdateCrawlDismount( me, toExit, onLadder );
return Continue();
}

// Build look target toward exit area center with vertical bias preserved
if ( m_pExitArea )
{
Expand Down Expand Up @@ -649,6 +670,100 @@ bool CNEOBotLadderClimb::IsDismountBlocked( CNEOBot *me, const Vector &toExit )

return tr.DidHit();
}
//---------------------------------------------------------------------------------------------
// Which way to crawl off toward the exit: along the face for an exit beside the ladder,
// since on the ladder a press with any part into the face climbs
Vector CNEOBotLadderClimb::GetCrawlDirection( const Vector &toExit ) const
{
if ( DotProduct( toExit, m_ladderForward ) >= 0.5f )
{
return toExit;
}

const Vector &normal = m_ladder->GetNormal();
Vector along = toExit - DotProduct( toExit, normal ) * normal;
along.z = 0.0f;
return ( along.NormalizeInPlace() > 0.0f ) ? along : toExit;
}

//---------------------------------------------------------------------------------------------
// Where the feet step off crawling: just above the ladder's top
float CNEOBotLadderClimb::GetCrawlFeetZ() const
{
return m_ladder->m_top.z + CRAWL_FEET_ABOVE_TOP;
}

//---------------------------------------------------------------------------------------------
// From the ladder's top toward the exit, the standing body is blocked but a crouched one is clear
bool CNEOBotLadderClimb::IsCrawlOnlyExit( CNEOBot *me, const Vector &toExit ) const
{
const IBody *body = me->GetBodyInterface();
const float halfWidth = body->GetHullWidth() * 0.5f;
const Vector mins( -halfWidth, -halfWidth, 0.0f );
const Vector standMaxs( halfWidth, halfWidth, body->GetStandHullHeight() );
const Vector crouchMaxs( halfWidth, halfWidth, body->GetCrouchHullHeight() );

Vector start = me->GetLocomotionInterface()->GetFeet();
start.z = GetCrawlFeetZ();
const Vector end = start + GetCrawlDirection( toExit ) * ( DISMOUNT_CLEARANCE_HULLS * body->GetHullWidth() );

trace_t tr;
UTIL_TraceHull( start, end, mins, standMaxs, MASK_NPCSOLID, me, COLLISION_GROUP_NONE, &tr );
if ( !tr.DidHit() )
{
return false;
}

UTIL_TraceHull( start, end, mins, crouchMaxs, MASK_NPCSOLID, me, COLLISION_GROUP_NONE, &tr );
return !tr.DidHit();
}

//---------------------------------------------------------------------------------------------
// Bot updates come a tenth of a second apart, too coarse to stop a climb inside the gap's few units,
// so the crouched bot is set just above the ladder's top, let go of the ladder and pushed into the gap:
//
// |#####| <- the gap's top
// ladder | o-> | landing
// || |_____|________ <- the gap's sill, the ladder's top
// || |#####|
void CNEOBotLadderClimb::UpdateCrawlDismount( CNEOBot *me, const Vector &toExit, bool bOnLadder )
{
me->PressCrouchButton( CRAWL_CROUCH_HOLD );
if ( bOnLadder && !m_bCrawlPushed )
{
m_bCrawlPushed = true;

Vector crawlPos = me->GetLocomotionInterface()->GetFeet();
crawlPos.z = GetCrawlFeetZ();
trace_t tr;
UTIL_TraceHull( crawlPos, crawlPos, me->WorldAlignMins(), me->WorldAlignMaxs(), MASK_PLAYERSOLID, me, COLLISION_GROUP_PLAYER_MOVEMENT, &tr );
if ( tr.startsolid )
{
return;
}

me->ReleaseMoveUpButton();
me->ReleaseForwardButton();
me->SetAbsOrigin( crawlPos );
me->SetMoveType( MOVETYPE_WALK );

// with a little rise, so the bot reaches the sill before it falls below it
Vector push = GetCrawlDirection( toExit ) * CRAWL_PUSH_SPEED;
push.z = CRAWL_PUSH_RISE_SPEED;
me->SetAbsVelocity( push );
return;
}

// Level, so the bot looks where it walks. In the air beside the ladder a press toward its face grabs it again,
// so the push alone carries the bot until it lands
me->GetBodyInterface()->AimHeadTowards( me->EyePosition() + toExit * 100.0f, IBody::MANDATORY, 0.1f, nullptr, "Crawling off the ladder" );
ILocomotion *mover = me->GetLocomotionInterface();
if ( mover->IsOnGround() )
{
mover->Approach( mover->GetFeet() + toExit * 100.0f );
}
}

//---------------------------------------------------------------------------------------------
void CNEOBotLadderClimb::EnterDismountPhase( CNEOBot *me )
{
Expand Down
12 changes: 12 additions & 0 deletions src/game/server/neo/bot/behavior/neo_bot_ladder_climb.h
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Original file line number Diff line number Diff line change
Expand Up @@ -35,6 +35,10 @@ class CNEOBotLadderClimb : public Action<CNEOBot>
bool IsNarrowLanding( CNEOBot *me ) const;
Vector GetDismountPos( CNEOBot *me ) const;
bool IsDismountBlocked( CNEOBot *me, const Vector &toExit ) const;
Vector GetCrawlDirection( const Vector &toExit ) const;
float GetCrawlFeetZ() const;
bool IsCrawlOnlyExit( CNEOBot *me, const Vector &toExit ) const;
void UpdateCrawlDismount( CNEOBot *me, const Vector &toExit, bool bOnLadder );
void ClaimLadder( CNEOBot *me ) const;

const CNavLadder *m_ladder;
Expand All @@ -43,6 +47,8 @@ class CNEOBotLadderClimb : public Action<CNEOBot>
bool m_bGoingUp;
bool m_bDismountPhase;
bool m_bJumpedOffLadder;
bool m_bCrawlDismount; // stepping off crouched, through a gap only a crouched body fits
bool m_bCrawlPushed; // set in the gap and pushed off the ladder

float m_flLastZ;
Vector m_dismountPos;
Expand All @@ -62,5 +68,11 @@ class CNEOBotLadderClimb : public Action<CNEOBot>
static constexpr float DISMOUNT_CLEARANCE_HULLS = 1.5f; // Hull widths toward the exit that must be clear to step off
static constexpr float NARROW_LANDING_HULLS = 0.5f; // Hull widths deep a landing must be to stand on (measured on dawn and dusk L1's 7 u wall cap)
static constexpr float LANDING_INSET = 16.0f; // How far inside a landing's near edge the dismount aims: half a hull, so the whole hull lands
static constexpr float CRAWL_FEET_ABOVE_TOP = 4.0f; // Crouched, the feet step off this far above the ladder's top
static constexpr float CRAWL_DUCK_RANGE = 64.0f; // How far below that height the climb ducks for a crawl exit: a few bot updates' climb
static constexpr float CRAWL_SNAP_DIST = 24.0f; // How far from that height the bot may be set there: a little over a bot update's climb
static constexpr float CRAWL_PUSH_SPEED = 150.0f; // How fast the bot is pushed off the ladder into the gap,
static constexpr float CRAWL_PUSH_RISE_SPEED = 40.0f; // and up, a unit's rise
static constexpr float CRAWL_CROUCH_HOLD = 0.3f; // Seconds each crouch press lasts, outliving a bot update
static constexpr int STALL_NUDGES = 3; // Sideways shimmies before a stalled climb jumps off (measured on subsurface L1 and saitama L2)
};
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