Attach Bone possible bug

[Yue]

I don't know how to explain this, but everything points to it having to do with the SetInput update. A mesh is positioned on the controller and follows it, and the mesh detaches in falling movements, depending on whether the update comes before or after the render. Now, when attaching a mesh to a specific bone, in my case the head bone, the same thing happens. but if I put it before the render, the helmet is not delayed in free fall, but the entire mesh is delayed from the SetInput controller. I found a solution to this that doesn't make much sense but works for me. If you use bone:SetScale in the main loop. 

boneHead:SetScale(1,1,1)
boneBack:SetScale(1,1,1)

everything works perfectly and behaves as I really expect it to. 

[Josh]

On 2/3/2026 at 8:26 AM, Yue said:

if I put it before the render

If you put what before the render? Entity:Attach() only needs to be called once.

I tried producing this error but even at 60 meters per second, there is only some small floating point fluttering, nothing like you showed in your video on Discord:

#include "Leadwerks.h"

using namespace Leadwerks;

int main(int argc, const char* argv[])
{
    //Get the displays
    auto displays = GetDisplays();

    //Create a window
    auto window = CreateWindow("Leadwerks", 0, 0, 1280 * displays[0]->scale, 720 * displays[0]->scale, displays[0], WINDOW_CENTER | WINDOW_TITLEBAR);

    //Create a framebuffer
    auto framebuffer = CreateFramebuffer(window);

    //Create a world
    auto world = CreateWorld();

    //Create a camera
    auto camera = CreateCamera(world);
    camera->SetClearColor(0.125);
    camera->SetFov(70);
    camera->Move(0, 2, -8);

    //Create light
    auto light = CreateBoxLight(world);
    light->SetRotation(45, 35, 0);
    light->SetRange(-10, 10);

    //Model by PixelMannen
    //https://opengameart.org/content/fox-and-shiba
    auto model = LoadModel(world, "https://github.com/Leadwerks/Documentation/raw/master/Assets/Models/Characters/Fox.glb");
    model->SetScale(0.05);
    model->Animate(1);
    model->SetRotation(0, -90, 0);

    auto neck = model->skeleton->FindBone("b_Neck_04");
    auto head = model->skeleton->FindBone("b_Head_05");
    Vec3 rotation;

    //Model by alissvetlana
    //https://sketchfab.com/3d-models/hat-a7f54e87bea94730b4a1827ec1f770df
    auto hat = LoadModel(world, "https://github.com/Leadwerks/Documentation/raw/master/Assets/Models/Characters/hat.glb");
    hat->SetScale(0.025);
    hat->SetPosition(-0.3, 0.4, 0);
    hat->Attach(model, head);

    //Main loop
    while (window->Closed() == false and window->KeyHit(KEY_ESCAPE) == false)
    {
        model->Translate(10, 0, 0);
        camera->Translate(10, 0, 0);

        world->Update();

        rotation.y = Cos(float(Millisecs()) / 10.0f) * 65.0f;
        neck->SetRotation(rotation);

        world->Render(framebuffer);
    }
    return 0;
}

 

[Yue]

I think it's because something happens with the entity's SetInput for the character controller. If I put it before the render, the controller breaks with the character's mesh visible, and if I put it after the render, the case separates. 

My Code. 

 

--##################################################################################
--## Project    : Astrocuco.
--## Scripter   : Yue Rexie.
--## File       : CInv.lua.
--###################################################################################
--## Notes : The object is instantiated.
--###################################################################################
CInv = {}
CInv.__index = CInv

function CInv:New(meshPlayer)
    local this = setmetatable({}, self)
    
    local world = meshPlayer:GetWorld()
    local player = meshPlayer
    
    local headBone = player.skeleton:FindBone("Head", true)
    local helmet = LoadModel(world, "Models/Player/Helmet/Helmet.mdl")
    helmet:SetHidden(false)
    helmet:SetPosition(0,-0.1,-0.05)
    helmet.name = "Helmet"
    helmet:Attach(player,headBone)

    local backBone = player.skeleton:FindBone("Spine2", true)
    local backpack = LoadModel(world, "Models/Player/Backpack/Backpack.mdl")
    backpack:SetHidden(false)
    backpack:SetPosition(0,-0.1,0.15)
    backpack.name = "Backpack"
    backpack:Attach(player,backBone)

    local elbowBoneL = player.skeleton:FindBone("LeftForeArm", true)
    local tablet = LoadModel(world, "Models/Player/Tablet/Tablet.mdl")
    tablet:SetHidden(false)
    tablet:SetPosition(0.1,0.04,0,false)
    tablet:SetRotation(-5,5,0)
    tablet.name = "Tablet"
    tablet:Attach(player,elbowBoneL)

    


    function this:Update() 
        headBone:SetScale(0.85,0.85,0.85)
        backBone:SetScale(1,1,1)
        elbowBoneL:SetScale(1,1,1)
    end

  
    
    function this:GetHelmet()
        return helmet
    end

    function this:GetBackpack()
        return backpack
    end

    function this:GetTablet()
        return tablet
    end
    
    return this
end

It's strange because the only way to fix it is to put it in the loop that scales the bones, and that solves it.
 

[Josh]

When you say "it" do you mean the call to Entity:SetInput?

[Yue]

28 minutes ago, Josh said:

When you say "it" do you mean the call to Entity:SetInput?

Yes.