Help:Patching the motorcycle area checks

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Revision as of 19:04, 16 September 2018 by imported>Leoetlino (Created page with "The Master Cycle Zero cannot be used in some areas. This article contains a list of checks that must be patched to remove usage restrictions. Most of them are located in a co...")
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The Master Cycle Zero cannot be used in some areas. This article contains a list of checks that must be patched to remove usage restrictions.

Most of them are located in a component that is nicknamed the “ride manager” (or “RideMgr” when following BotW’s naming conventions) since it manages both horses[check] and the Master Cycle Zero.

The game uses the current climate for the area check[1]:

  • ✅ HyrulePlainClimate
  • ✅ NorthHyrulePlainClimate
  • ✅ HebraFrostClimate
  • ✅ TabantaAridClimate
  • ✅ FrostClimate
  • 🚫 GerudoDesertClimate
  • ✅ GerudoPlateauClimate
  • ✅ EldinClimateLv0
  • ✅ TamourPlainClimate
  • ✅ ZoraTemperateClimate
  • ✅ HateruPlainClimate
  • ✅ FiloneSubtropicalClimate
  • ✅ SouthHateruHumidTemperateClimate
  • 🚫 EldinClimateLv1
  • 🚫 EldinClimateLv2
  • ✅ DarkWoodsClimat
  • ✅ LostWoodClimate
  • ✅ GerudoFrostClimate
  • ✅ KorogForest
  • 🚫 GerudoDesertClimateLv2


Disappearing when entering a blacklisted climate

Called from the Motorcycle AI root code.

if ( v6 && !RideMgr::motorcycleCanBeUsed(v6, (float *)&v68, 0LL) )  // 0x71004ADF18
  goto triggerDisappear;

Either change the condition to be always false, or change RideMgr::motorcycleCanBeUsed (preferred to avoid side effects):

bool RideMgr::motorcycleCanBeUsed(RideMgr* this, Vec3 *positions, __int64 a3) // 0x7100679D10
{
  if ( (a3 || (a3 = ActorSystem::sInstance->field_C0) != 0)
    && (*(__int64 (__fastcall **)(__int64))(*(_QWORD *)a3 + 0x180LL))(a3) & 1 )
  {
    return false;
  }
  if ( WorldMgr::sInstance
         && (v5 = (u64)WorldMgr::getClimateNum(WorldMgr::sInstance, positions) - 5, v5 <= 14) )
  {
    return (0x3CFEu >> v5) & 1;
  }
  return true;
}

Patch:

.text:0000007100679D84                 AND             W0, W8, #1

To:

.text:0000007100679D84                 MOV             W0, #1

Rune UI/sound effect

Same climate based check as above, but done in a different RideMgr function. Just change:

.text:0000007100679650 TBNZ            W8, #0, loc_710067965C

to:

.text:0000007100679650 B               loc_710067965C

Refusing to spawn when in a blacklisted climate

Check 1

Deep in some RideMgr function, called from the PlayerNormal AI:

else if ( !WorldMgr::sInstance
       || (v7 = (unsigned __int64)WorldMgr::getClimateNum(WorldMgr::sInstance, (float *)v4) - 5, v7 > 0xE)
       || (0x3CFEu >> v7) & 1 )
{
  v8 = (*(__int64 (**)(void))(**(_QWORD **)(HavokAI::sInstance->navMeshQueryReqPool + 0x1A0LL) + 0x30LL))();
  ...
}

Patch:

.text:0000007100679BA8                 CBZ             X0, loc_7100679BD8

to:

.text:0000007100679BA8                 B               loc_7100679BD8

so that the game always executes the code inside of the if block.

Check 2

Found in another RideMgr member function and also called from the PlayerNormal AI code.

bool RideMgr::checkUsable2(RideMgr *this, __int64 a2)
{
  if ( this->someFlag == 1 )
    return 0;
  float* v4 = this->gap12C;
  RideMgr::x_7(this, (float *)this->gap12C, (__int64)&this->field_134 + 4);
  if ( a2 || (a2 = ActorSystem::sInstance->field_C0) != 0 )
  {
    if ( (*(__int64 (__fastcall **)(__int64))(*(_QWORD *)a2 + 0x180LL))(a2) & 1 )
      return 0;
  }
  if ( !WorldMgr::sInstance )
    return 1;
  unsigned int climateNumMinus5 = WorldMgr::getClimateNum(WorldMgr::sInstance, v4) - 5;
  return ( climateNumMinus5 > 14 || (0x3CFEu >> climateNumMinus5) & 1 );
}

Change:

.text:000000710067B5FC                 CBZ             X0, loc_710067B62C

to:

.text:000000710067B5FC                 B               loc_710067B62C

to make the game always return “true”.

Disappearing when being away from the motorcycle

This is checked by Motorcycle AI root code (at 0x71004ADF28).

v40 = (float *)PlayerInfo::getPlayerPos(PlayerInfo::sInstance);
if ( (float)((float)((float)(*(float *)&v68 - *v40) * (float)(*(float *)&v68 - *v40))
           + (float)((float)(*(float *)&v70 - v40[2]) * (float)(*(float *)&v70 - v40[2]))) > (float)(**(float **)&this->_4abuf[8] * **(float **)&this->_4abuf[8]) )
  goto triggerDisappear;

It is easy to change this condition to be always false.

Other checks[2]

Actor check

If the actor cannot be loaded, the game will not allow the player to use the motorcycle and will show the regular “You can’t use that here” message.

6 or 7 other checks

The RideMgr function at 0x7100678E80 calls 6 member functions that must all return true; otherwise, the motorcycle cannot be used.

The first 4 functions appear to be using the Havok AI NavMesh system. Something called “motorcycle shape cast” is used in the 3 other functions.

  1. Extracted check from Switch 1.5.0
  2. 0x7100678E80 in Switch 1.5.0