Kawaii Physics for Player Model Swaps

Using Unreal Editors Compatible Skeletons to add Custom Bones and apply physics to them

• Written by: ReapersVigilance

Overview

This guide is to show how to setup your model with UE's compatible skeletons to activate Kawaii physics and collision. FOR CUSTOM ADDED BONES

I am assuming you understand the concept and setup of model swapping including the extraction from FModel, Importing to Blender, Weight painting, and Export from Blender. I will touch on them briefly however. Other guides are quite detailed in doing all of the above.

I'm going to Write this as a full Model Swap however it can be done with just Hair/Head Models as long as you use a dummy SK_PalHuman_Skeleton in the proper folder.

process is very similar to a normal model swap except for some key differences in the Exporting from blender and UE work.

Critical Notes

• This method works for adding physics to CUSTOM BONES in both Hair and Head Swaps. It does NOT work for adding physics bones to Outfit swaps. (Unless you like T-posing everywhere)So it works best doing them all together and choosing which Kawaii parts will be Hair and which will be Head.
  • Can be done using only Hair swap or only Head swap for the Kawaii Items if preferred.
• As long as you're adding physics to Default Bones on an Outfit, that'll work without the Compatible Skeletons. Can skip right to the Kawaii section for that.

This is absolutely not a replacement for the bone reorder and animation tool by Shifty It just allows you to add physics to swaps without breaking the animations.

Can be used in combination with Jiggle Physics (18+) guide by Dytser

Tools Needed

• FModel; Allows you to extract, view, and find files from the game
  • Updated Mapping file for Palworld
    • Can be found on the Palworld Modding Community Discord
• Blender; 3D Modeling Software
  • psk/psa importer
    • for Versions 2.8-2.9
    • for Version 4.1
• Unreal Engine 5.1.1
• Kawaii Physics Plugin 1.10; Physics Simulation Addon for UE used by the game
  • Specific version ~ KawaiiPhysics_5_1_20221203.zip
• UnrealPak; For compiling into game readable pak files
  • Can be found on the Palworld Modding Community Discord

Preview

See Gif 01 for a brief preview of what this guide accomplishes

Reference File Name/Description	Reference File
Gif 01 - Preview A preview of what will be done using this guide The Body/Arms/Legs/Head are an Outfit Swap The Ears are a Hair Swap The Tail and Spikes are a Head Swap Note that the objects included in the Head and Hair Swaps have Enabled Physics

Full Process

Step 1 _ (FModel and Blender) - File Prep

• Standard Model Swap process to begin
  • The Psk you will need to Export from FModel is the SK_Player_Female from the path Pal/Content/Pal/Model/Character/Player/Body/Female this comes with the SK_PalHuman_Skeleton we need
    • can be done with one of the outfit skeletons as well as they reference the same.
• Import this psk into blender along with the model you will be swapping. SEE IMAGE 01
• From here is the same as a normal model swap with aligning your model and applying your model to the game skeleton.

Reference File Name/Description	Reference File
Image_01 - Default A preview of what will be done using this guide The Body/Arms/Legs/Head are an Outfit Swap The Ears are a Hair Swap The Tail and Spikes are a Head Swap Note that the objects included in the Head and Hair Swaps have Enabled Physics

Step 2 _ (Blender) - Add Bones and Painting

• You can now add bones to the skeleton that will reference any part you want Kawaii Physics
  • Hair, Tail, Ears, Dangling parts, Whatever
  • Have the last bone of these parts off of the model. It helps for the physics later. SEE IMAGE 02
  • ENSURE THESE BONES ATTACH TO OTHER BONES
    • Example: parent the first bone of a hair chain to the head bone,
      or parent the first tail bone to the spine_01 bone.
• Weight paint.
  • Whether you do it manually or use Mesh Data Transfer from the original game model.
    Tweak as necessary for your new bones.
  • That last bone thats slightly hanging off will need to influence the very tip of whatever part its attached it.

Reference File Name/Description	Reference File
Image_02 - Custom Bones An example of Custom added bones The 4 bone chain for the ears linked to the head bone The 3 bone chains for each spike linked to the clavicles The 7 bone chain for the tail linked to the spine

• There is an in game bug regarding Mounted Combat that needs to be worked around at this point or it will affect everything from here on. SEE IMAGE 18
  • Any Custom added bones Above the Waist will error when aiming side to side while mounted. This has something to do with the animation lock of the root bone.
  • To Fix. all above waist added bones must use names of existing in game bones that are not being used by the Outfit Swap.
    • All the Hair bones can be used to fix this SEE IMAGE 19
      • List of Hair Bones compiled and provided by BackwoodsBeast from the Palworld Modding Community Discord
  • This bug persists on anything with applied physics even if not using Kawaii. ie. spring controllers for jiggle physics
    • I recommend repurposing the backpack bones as weight paint for breasts

Reference File Name/Description	Reference File
Image_18 - Mounted_Bug Shows the Bug of using custom bones while in mounted combat Notice the bone tree items marked RenaEar Even though im facing left of the mount The ears still pull straight back
Image_19 - Mounted_Bug_Fix The fix Using the exxact same bones With identical weight paint Only difference if you look at the tree the bones are renamed to default hair bones

Step 3 _ (Blender) - Dividing up the Model

• You now need to split your model into the Necessary Parts that are going to be your Outfit Swap, Head Swap, and Hair Swap.
  • For my exaple the Ears are a Hair Swap, The Tail and Back spikes are a Head Swap, and Everything else is an Outfit Swap
  • Keep in mind that some helmets overwrite the hair, so if you dont want your Hair Swap to disappear in those instances you can combine the Hair Swap and Head Swap into just a Head Swap.
• Keep in mind you only need to separate the meshes but everything can stay attached to the same Armature SEE IMAGES 03, 04, and 05
  • I added small spheres onto the connection bone as i occasionally had a bone error on importing to UE but it was not consistent. Those spheres stopped it completely.
• Export these as 3 separate FBX files with the armature in each one. just like the images.

Reference File Name/Description	Reference File
Image_03 - Hair_FBX This shows the active parts for the Hair Swap Make sure to select these and use Selected Only when exporting Ensure you armature is named Armature
Image_04 - Head_FBX This shows the active parts for the Head Swap Make sure to select these and use Selected Only when exporting Ensure you armature is named Armature
Image_05 - Outfit_FBX This shows the active parts for the Outfit Swap Make sure to select these and use Selected Only when exporting Ensure you armature is named Armature

Step 4 _ (UE) - Import Setup

• UE folder setup is the same as any normal model swap as well as all your cooking settings SEE IMAGE 06
  • I am only doing an Outfit Swap of the Old Cloth in this example, If you're doing other outfits then you'll need those too.
  • note that the Hair Swap and Head Swap can be done with any head and hair, not just 001 as i am showing here

Reference File Name/Description	Reference File
Image_06 - File_Structure The Standard Model Swap file structure More or Differnt Folders may be required for your specific swap Adjust as required

Step 5 _ (UE) - Import Outfit FBX

• Standard model swap applies here
• Import your FBX into the folder SK_Player_Female_Outfit_OldCloth001
  • Rename Skeleton to SK_PalHuman_Skeleton, and move to the Human Folder SEE IMAGE 07
  • Rename Physics Asset to SK_Player_Female_PhysicsAsset, and move to the Female Folder SEE IMAGE 08
  • Rename Skeletal Mesh to SK_Player_Female_Outfit_OldCloth001 SEE IMAGE 09
• Renaming materials and Textures is up to you, or may depend on what kind of swap you are doing
• If you have more outfits, rename and relink skeleton and physics asset as necessary.

• Optional set up of Kawaii Collision Asset
  • Right click on the Skeletal Mesh and Create an Animation Blueprint
    • You may already have one if jiggle physics are enabled
  • Use this model to create the Collision Asset as you can see all collidable entities
    • I wont go into detail on this as its quite involved but I will link a very informative Video at the end of this for how to do it.
      • Experiment with your Collision objects as you need.
      • SEE IMAGE 20 for sample
  • If you dont set up the Collision Asset the physics will still work, they just may clip with your model

Reference File Name/Description	Reference File
Image_07 - Outfit_Skeleton_Location Shows the Location of the Skeleton for the Outfit Swap Ensure the name of your file matches
Image_08 - Outfit_PA_Location Shows the Location of the Physics Asset for the Outfit Swap Ensure the name of your file matches
Image_09 - Outfit_Mesh_Location Shows the Location of the Skeletal Mesh for the Outfit Swap Ensure the name of your Skeletal Mesh matches The other files can be named as you like More or Differnt Folders may be required for your specific swap
Image_20 - Kawaii_Sample Shows a sample of the Kawaii Collision Asset This collision specific for stopping the tail from clipping with the legs Second image shows how it looks pulled into the other swaps after setup

Step 6 _ (UE) - Import Hair FBX

• Import your FBX into the folder Hair001
  • Rename Skeletal Mesh to SK_Player_Hair001
• Renaming anything else is up to you
• Right click on the Skeletal Mesh and Create an Animation Blueprint
• Open the Physics Asset that was auto generated upon import
  • We dont need anything here as it will be controlled by Kawaii
    • Delete everything under the skeleton tree
    • Save and Close
      Possible that setting this up further will add collision between the hair and the world around, needs more testing
• Open the Skeletal Mesh
  • under the Asset Details Tab, Scroll down until you find the Post Process Anim Blueprint and set it to the one you just Created SEE IMAGE 10
• Open the Skeleton
  • Under the Asset Details Tab, Add a Compatible Skeleton and set it to the SK_PalHuman_Skeleton from the Outfit FBX SEE IMAGE 11
    • IMPORTANT This tab might be hidden by default for you, click on Window on the top bar to turn it on
  • If you would like helmets to be visible with your swap then you need to add replacement Skeletal Sockets to the head bone
    • Relative Position of these sockets can be found using FModel however may need adjustment specific to your model
      • Socket_HairAttach_HeadEquip_top01
        • Controls the following Helmets: Monarch's Crown, Golden Crown, Graduation Cap, Witch's Crown (Ultra)
      • Socket_HairAttach_HeadEquip_top02
        • Controls the following Helmets: Long-eared Headband
      • Socket_HairAttach_HeadEquip_top03
        • Controls the following Helmets: Silk Hat
      • Socket_HairAttach_HeadEquip_front
        • Controls the following Helmets: Metal Helm, Refined Metal Helm, Pal Metal Helm
      • Socket_HairAttach_Ear02_L
        • Controls the following Helmets: Feathered Hair Band
      • Not Controlled by Sockets in the Hair as they replace the Hair when equipped
        • Following helmets: Soft Hat, Tocotoco Cap, Grinning Tocotoco Cap, Farming Hat, Tricorne, Helmet, Bowler Hat, Gumoss Cap, Penking Cap, Katress Cap, Witch Hat
        • IMPORTANT Equipping any of these will hide the entire Kawaii Hair File and add a small Hair effect linked to the model
• Open the Animation Blueprint
  • Set up your Kawaii physics and Collision. SEE IMAGE 12
    • I wont go into detail on this as its quite involved but I will link a very informative Video at the end of this for how to do it.
      • Experiment with your settings as you need.
• SEE IMAGE 13 FOR FINALIZED FOLDER

Reference File Name/Description	Reference File
Image_10 - Hair_SkeletalMesh Shows the Opened Skeletal Mesh File Under Asset Details/Skeletal Mesh/Post Process Anim Blueprint Set the Anim Blueprint Created during this step
Image_11 - Hair_Skeleton Shows the Opened Skeleton File Under Asset Details/Compatible Skeletons/ Use the + symbol to add a line Set the SK_PalHuman_Skeleton Created during the Outfit Swap
Image_12 - Hair_AnimBP Shows the Opened Animation Blueprint File use the Kawaii Video Guide for setting up Show values are an example
Image_13 - Hair_Folder Shows a final version of the set up Hair Folder

Step 7 _ (UE) - Import Head FBX

• Import your FBX into the folder Head001
  • Rename Skeletal Mesh to SK_Player_Female_Head001
• Renaming anything else is up to you
• Right click on the Skeletal Mesh and Create an Animation Blueprint
• Open the Physics Asset that was auto generated upon import
  • We dont need anything here as it will be controlled by Kawaii
    • Delete everything under the skeleton tree
    • Save and Close
      Possible that setting this up further will add collision between the head parts and the world around, needs more testing
• Open the Skeletal Mesh
  • under the Asset Details Tab, Scroll down until you find the Post Process Anim Blueprint and set it to the one you just Created SEE IMAGE 14
• Open the Skeleton
  • Under the Asset Details Tab, Add a Compatible Skeleton and set it to the SK_PalHuman_Skeleton from the Outfit FBX SEE IMAGE 15
    • IMPORTANT This tab might be hidden by default for you, click on Window on the top bar to turn it on
• Open the Animation Blueprint
  • Set up your Kawaii physics and Collision. SEE IMAGE 16
    • I wont go into detail on this as its quite involved but I will link a very informative Video at the end of this for how to do it.
      • Experiment with your settings as you need.
• SEE IMAGE 17 FOR FINALIZED FOLDER

Reference File Name/Description	Reference File
Image_14 - Head_SkeletalMesh Shows the Opened Skeletal Mesh File Under Asset Details/Skeletal Mesh/Post Process Anim Blueprint Set the Anim Blueprint Created during this step
Image_15 - Head_Skeleton Shows the Opened Skeleton File Under Asset Details/Compatible Skeletons/ Use the + symbol to add a line Set the SK_PalHuman_Skeleton Created during the Outfit Swap
Image_16 - Head_AnimBP Shows the Opened Animation Blueprint File use the Kawaii Video Guide for setting up Show values are an example
Image_17 - Head_Folder Shows a final version of the set up Hair Folder

Step 8 - Finishing Touches

• From here most everything is the same as a normal model swap so i will only go over it quickly and call attention to things that need it
  • Cook like normal
  • Copy into your Pak file structure and remove the skeleton in the Human folder, and the Physics asset in the Female Folder
    • CRITICAL The skeleton and assets in the Head001 folder and Hair001 folder must STAY in the Pak
  • Use UnrealPak to make your Pak file
  • Drop into your game files

Step 9 - Finish

• Enjoy a model swap with Kawaii Physics and Collision. Thats it

Resources

Kawaii Video Guide

• https://www.youtube.com/watch?v=H4Gf6XMWh8I&t=1s