Actor Replacement

This tutorial will show you how to replace any actor, object, or variable in the game, with the exception of those which are dynamically spawned.

Reference Material

Finding Room Headers

1. Open the Ocarina of Time Debug ROM or Ocarina of Time 1.0 in Nemu64.
2. Go to the room you wish to find the header for.
3. Go to Nemu's Plugins menu and choose Debugger:Memory.
4. Type 80223CE8 (Debug ROM) or 80120C44 (1.0) into the address box.
   • This will bring you to 80223CE8, where you'll find the current room address in the first column.
5. Paste the address of the current room into the address box.
6. This will bring you to the room header.

Understanding Room Headers

More details about these commands can be found on the Scenes and Rooms page.

18000000 bboooooo
16000000 000000yy	08xx0000 0000yyzz
12000000 xx010000	10000000 xxxxyy00
0A000000 bboooooo	0Bxx0000 bboooooo
01xx0000 bboooooo	14000000 00000000

• Alternate Setups List: 18000000 bboooooo
  • Optional. If it doesn't exist, the scene only has one setup. If it does exist, it will have multiple scene setups

• Sound Settings: 16000000 000000yy
  • y sets the echo level of the sound effects

• Room Behavior Settings: 08xx0000 0000yyzz
  • x and z affect various properties, such as Link's idling animation. This command hasn't been fully documented yet.

• Skybox Settings: 12000000 xx000000
  • If x ≠ 0, the skybox will be disabled.

• Time Settings: 10000000 xxxxyy00
  • x sets the time of day when entering the room.
    • If x = FFFF, the room defaults to the current game time.
  • y sets the speed at which time flows. The value can be negative.

• Mesh Header Location: 0A000000 bboooooo
  • b is the bank index. 03 is used to reference the current room file.
  • o is the location of the room's mesh header, relative to the start of the file. This renders the room's model.
    • room header address + o = location of mesh header

• Object List: 0Bxx0000 bboooooo
  • x indicates the number of objects.
  • b is the bank index. 03 is used to reference the current room file.
  • o is the location of the room's object list, relative to the start of the file.
    • room header address + o = location of object list

• Actor List: 01xx0000 bboooooo
  • x indicates the number of actors.
  • b is the bank index. 03 is used to reference the current room file.
  • o is the location of the room's actor list, relative to the start of the file.
    • room header address + o = location of actor list

• End of Header Command: 14000000 00000000
  • This command tells the game that the header ends here.

Understanding Actor Lists

Each line represents a different actor.

aaaaxxxx yyyyzzzz	ccddee0B 0000vvvv
aaaaxxxx yyyyzzzz	ccddee00 0000vvvv
aaaaxxxx yyyyzzzz	ccddee9F 0000vvvv
aaaaxxxx yyyyzzzz	ccddee00 0000vvvv
aaaaxxxx yyyyzzzz	ccddee00 0000vvvv
aaaaxxxx yyyyzzzz	ccddee00 0000vvvv
aaaaxxxx yyyyzzzz	ccddee00 0000vvvv

• aaaa = Actor Number
• xxxx = X Coordinates (Hex)
• yyyy = Y Coordinates (Hex)
• zzzz = Z Coordinates (Hex)
• cc = X Rotation (Hex)
• dd = Y Rotation (Hex)
• ee = Z Rotation (Hex)
• vvvv = Variable Number

Understanding Object Lists

Each group of four digits/two bytes (ex. 01A5) comprises an object number. If a room has an odd number of objects (05 in this example), you only need to pay attention to the first five groups of four digits.

aaaabbbb ccccdddd

eeee0000 0163FFC8

• aaaa = Object #1
• bbbb = Object #2
• cccc = Object #3
• dddd = Object #4
• eeee = Object #5
• 0000 = Padding

Look up the object numbers here.

Tutorial: Replacing a Treasure Chest in Mido's House

What You'll Need

1. Nemu64 Emulator
2. Ocarina of Time Debug ROM
3. Hex Calculator

Open Windows Calculator, change it to "Programmer" mode, and press the Hex button. Or, use an online calculator like this one.

Room Header

Finding the Room Header

1. Go to Mido's House (Map 49 in Map Select) as Child Link.
2. Go to Nemu's Plugins menu and choose Debugger:Memory.
3. Type 80223CE8 into the address box.
   • This will bring you to 80223CE8, where you'll find the current room address in the first column.
   • The memory address for Mido's House is 80262880.
4. Paste the address of the current room (80262880) into the address box.
5. This will bring you to 80262880, where you'll find the room header.

Deciphering the Room Header

Below is the room header for Mido's House, located at 80262880. Use it to find the number of scene setups, the number of objects, the address of the object list, the number of actors, and the address of the actor list.

16000000 00000003	08020000 00000005
12000000 00010000	10000000 FFFF0000
0A000000 030000C0	0B050000 03000040
01070000 0300004C	14000000 00000000

• Scene Settings: xx000000 000000yy
  • If xx = 16, the room has one scene setup.
  • If xx = 18, the room has multiple scene setups.

xx = 16 - Mido's house has one scene setup.

• Object List: 0Bxx0000 000000yy
  • xx indicates the number of objects.
  • yy is the location of the room's object list.
    • room header address + yy = location of object list

xx = 05 - There are 05 objects in the room.
yy = 40 - The location of the object list is 80262880 + 40, which is 802628C0.

• Actor List: 01xx0000 000000yy
  • xx indicates the number of actors.
  • yy is the location of the room's actor list.
    • room header address + yy = location of actor list

xx = 07 - There are 07 actors in the room.
yy = 4C - The location of the actor list is 80262880 + 4C, which is 802628CC.

Actors

Finding the Actor List

1. Type 802628CC, the location of the actor list, into the address box.
   • This will bring you to 802628CC, where you'll find a list of actors.
2. Look up the actor numbers.
3. Look up the variables.
4. Replace them with whatever you want.

Deciphering the Actor List

Below is the actor list for Mido's House, located at 802628CC. Each line represents an actor. Mido's House has 07 actors, so there are 07 lines.

0163FFC8 00100080	0000960B 0000FF04
016D0003 00300086	00008000 0000FF00
0163FF83 000C0048	0000549F 0000FF00
000A003A 0000FFC9	00004000 000059A0
000A003A 00000023	00004000 000059A1
000AFFC4 0000FFC9	0000C000 00005982
000AFFC4 00000023	0000C000 00005903

The first four digits in each line comprise an actor number. Cross-reference them with this list.

Actor #	Filename	Actor ID	X	Y	Z	Variable #	Variable ID	Object #
0163	ovl_En_Ko	Kokiri Child	FFC8	0010	0080	FF04	???	0001
016D	ovl_En_Md	Mido	0003	0030	0086	FF00	???	00FB
0163	ovl_En_Ko	Kokiri Child	FF83	000C	0048	FF00	???	0001
000A	ovl_En_Box	Treasure Chest	003A	0000	FFC9	59A0	???	000E
000A	ovl_En_Box	Treasure Chest	003A	0000	0023	59A1	???	000E
000A	ovl_En_Box	Treasure Chest	FFC4	0000	FFC9	5982	???	000E
000A	ovl_En_Box	Treasure Chest	FFC4	0000	0023	5903	???	000E

Replacing Actors

1. Find the actor number of the actor you wish to replace.
   • Let's replace the treasure chest in line 4. (000A)
2. Find the actor number of the actor you wish to replace it with.
   • Let's replace the treasure chest (000A) with a sign (0141).
3. Overwrite the old actor number with the new one.
   • 000A003A 0000FFC9 00004000 000059A0 -> 000A003A 0000FFC9 00004000 000059A0
4. Find the variable number of the actor you wish to replace.
   • The variable of the treasure chest in line 4 is 59A0.
5. Find the variable number you will use for the new actor.
   • Let's make our sign say "XXXX". (XXXX)
6. Overwrite the old variable number with the new one.
   • 000A003A 0000FFC9 00004000 000059A0 -> 000A003A 0000FFC9 00004000 0000XXXX

Objects

Finding the Object List

1. Type 802628C0, the location of the object list, into the address box.
   • This will bring you to 802628C0, where you'll find a list of objects.
2. Look up the object numbers.
3. Replace them with whatever you want.

Deciphering the Object List

Below is the object list for Mido's House, located at 802628C0. Each group of four digits comprises an object number. Cross-reference them with this list. Mido's House has 05 objects, so we only need to pay attention to the first five groups of four digits.

00C500FC 00FD00FB

000E0000 0163FFC8

These numbers correspond to the following:

Object #	Filename	Object ID
00C5	object_os_anime	Required by human-like npcs
00FC	object_km1	Strawberry-Haired Kokiri Boy
00FD	object_kw1	Strawberry-Haired Kokiri Girl
00FB	object_md	Mido
000E	object_box	Treasure Chest/Boss Key Chest/Light When Opening Chest

Replacing Objects

1. Use the Actor List to find the object linked to the actor you wish to replace.
   • We've chosen to replace a treasure chest, which is linked to object 000E (Treasure Chest/Boss Key Chest/Light When Opening Chest).
2. Use the Actor List to find the object linked to the actor you wish to replace it with.
   • We've chosen to replace the treasure chest (object 000E) with a sign (object 012F).
3. Overwrite the old object number with the new one.
   • 00C500FC 00FD00FB 000E0000 0163FFC8 -> 00C500FC 00FD00FB 012F0000 0163FFC8

Gameshark Codes

Debug ROM

Spin Attack Spawner

Spawns an actor that uses object 0000, 0001, 0002, or 0003 each time Link performs a spin attack.

813D7756 aaaa
813D7740 2409
813D7742 vvvv

• 0000 = Always Loaded
• 0001 = Loaded Indoors
• 0002 = Loaded Outdoors
• 0003 = Loaded in Dungeons

Replace Saria in Saria's House (Child)

Replaces Saria in Saria's House as Child Link.

8126A956 oooo
8126A96C aaaa
8126A97A vvvv

Replaces Saria in Saria's House as Child Link, for actors that use object 0000 or 0001.

8126A96C aaaa
8126A97A vvvv

Replace Warp Pad in Temple of Time (Child)

Replaces the Light Medallion warp pad in the Temple of Time as Child Link.

81288060 oooo
81288064 aaaa
81288072 vvvv

Replaces the Light Medallion warp pad in the Temple of Time as Child Link, for actors that use object 0000 or 0001.

81288064 aaaa
81288072 vvvv

Replace Nabooru in Spirit Temple (Child)

Replaces Nabooru kneeling beside the crawling hole in the first room of the Spirit Temple.

81273086 oooo
81273174 aaaa
81273182 vvvv

Replaces Nabooru kneeling beside the crawling hole in the first room of the Spirit Temple, for actors that use object 0000 or 0003.

81273174 aaaa
81273182 vvvv

Replace Beamos in Fire Temple Mini-Dungeon

Replaces the Beamos in the fire temple mini-dungeon in Ganon's Tower.

8128D0BC oooo
8128D1C0 aaaa
8128D1CE vvvv

For actors using object 0000 or 0003:

8128D1C0 aaaa
8128D1CE vvvv

Replace Fishing Pond Objects in Fishing Pond (Child)

Replaces the fishing pond objects actor (the fisherman, the sign, the fish, etc.), placing the new actor in the center of the pond.

81283780 oooo
81283784 aaaa
81283792 vvvv

For actors using object 0000 or 0002(?):

81283784 aaaa
81283792 vvvv

Replace Warp Pad in Desert Colossus (Child)

Replaces the warp pad in the Desert Colossus.

81284538 oooo
812846D0 aaaa
812846DE vvvv

For actors using object 0000 or 0002:

812846D0 aaaa
812846DE vvvv

Replace Warp Pad in Death Mountain Crater

Replaces the warp pad in the Death Mountain Crater.

81281710 oooo
81281878 aaaa
81281886 vvvv

For actors using object 0000 or 0002:

81281878 aaaa
81281886 vvvv

Replace Boy in Kokiri Forest (Child)

Replaces the rock-pulling boy in Kokiri Forest.

8128D7C0 oooo
8128D844 aaaa
8128D852 vvvv

For actors using object 0000 or 0002:

8128D844 aaaa
8128D852 vvvv

Replace Freezard in Ice Cavern

Replaces the first Freezard when going through the Ice Cavern.

8129AE7E oooo
8129AE94 aaaa
8129AEA2 vvvv

For actors using object 0000 or 0003:

8129AE94 aaaa
8129AEA2 vvvv

Replace Bonooru in Sasa Test

Replaces Bonooru the Scarecrow in the Child (Day) setup of Sasa Test.

812965DC oooo
812964E4 aaaa
812964F2 vvvv

For actors using object 0000 or 0002:

812964E4 aaaa
812964F2 vvvv

Replace Dark Link in Sutaru

Replaces Dark Link in Sutaru.

812B0BD0 oooo
812B0BE0 aaaa
812B0BEE vvvv

For actors using object 0000 or 0003:

812B0BE0 aaaa
812B0BEE vvvv

OoT (U/J) 1.0

Replace Boy in Kokiri Forest

Replaces the boy pulling rocks outside of Mido's House in Kokiri Forest.

81244096 oooo
81244124 aaaa
81244132 vvvv

Replaces the boy pulling rocks outside of Mido's House in Kokiri Forest, for actors that use object 0000 or 0002.

81244124 aaaa
81244132 vvvv

Replace Heart in Saria's House

Replaces the heart closest to the door and furthest from the camera in Saria's House.

81221108 oooo
8122112C aaaa
8122113A vvvv

Replaces the heart closest to the door and furthest from the camera in Saria's House, for actors that use object 0000 or 0001.

8122112C aaaa
8122113A vvvv

Replace Treasure Chest in Deku Tree

Replaces the treasure chest in the central room of the Deku Tree.

81234128 oooo
81234218 aaaa
81234226 vvvv

Replaces the treasure chest in the central room of the Deku Tree, for actors that use object 0000 or 0003.

81234218 aaaa
81234226 vvvv

Replace Wolfos in Sacred Forest Meadow

Replaces the Wolfos at the entrance to the Sacred Forest Meadow.

81259F3A oooo
81259F50 aaaa
81259F5E vvvv

Replace Guard in Kakariko Village

Replaces the guard beside the entrance in Kakariko Village.

8123A92C oooo
8123AC34 aaaa
8123AC42 vvvv

Replace Pot in Lon Lon Ranch

Replaces the pot nearest the entrance in Lon Lon Ranch.

8124851C oooo
81248564 aaaa
81248572 vvvv

Replace Sign in Zora's Domain

Replaces the sign beside the entrance in Zora's Domain.

8126097C oooo
81260A38 aaaa
81260A46 vvvv

Replace Sign in Gerudo Valley

Replaces the sign beside the entrance in Gerudo Valley.

81247260 oooo
8124732C aaaa
8124733A vvvv

Replace Wolfos in Forest Temple Entryway

Replaces the Wolfos in the first room of the Forest Temple.

81231CD4 oooo
81231CE4 aaaa
81231CF2 vvvv