Attaching object to bone.

[Gugis]

Is there any way to attach 3D object to bone? For example attaching sword to hand, so sword would move along hand.

[GameMonetize]

You can use parenting (sword.parent = hand). Doing that the sword will inherit all hand's transformations

[vbillet]

I Assume sword is a mesh (BABYLON.Mesh) and Armature is a skeleton (BABYLON.Skeleton) containing one bone (BABYLON.bones).

 

In engine.runRenderLoop function, I use the following code :

engine.runRenderLoop(function() {	sword.parent=Armature.bones[0];	scene.render();});

It result the following error : 

Uncaught TypeError: Object [object Object] has no method 'isEnabled'

 

And if I use the following code : 

engine.runRenderLoop(function() {	scene.render();	sword.parent=Armature.bones[0];});

It result the following error : 

Uncaught TypeError: Object [object Object] has no method '_needToSynchonizeChildren'

 

In both cases, sword does not follow bone's motion.

 

Any Idea about this ?

[GameMonetize]

Hello,

a bone cannot be attached this way. You have to set sword.skeleton=skeleton

but you also have to define matrices weights and indices into your sword

[GameMonetize]

https://github.com/BabylonJS/Babylon.js/wiki/How-to-use-bones-and-skeletons

[vbillet]

Hello,

a bone cannot be attached this way. You have to set sword.skeleton=skeleton

but you also have to define matrices weights and indices into your sword

How can I do this ?

matricesWeights = ???;floatIndices = ???;sword.setVerticesData(matricesWeights, BABYLON.VertexBuffer.MatricesWeightsKind, false);sword.setVerticesData(floatIndices, BABYLON.VertexBuffer.MatricesIndicesKind, false); 

It's not easy to understand.

Is it 4 float per vertex ? only 4 floats ?

finally an example could be fine ....

[vbillet]

Thanks for your help.

Finally here is my code : 

function mount(obj,ske,boneName){	matricesWeights =[];	floatIndices =[];        boneIndice=-1;	// Find bone's Indice	for (ii=0;ii<ske.bones.length;ii++)	{		if (ske.bones[ii].name==boneName)		{			boneIndice=ii;			break;		}	}        if (boneIndice==-1) {console.error("Unable to find bone : "+boneName); return;}	// Build matrices and indices buffers.	for (ii=0;ii<obj._totalVertices;ii++)	{		matricesWeights[ii*4+0]=1.0;		matricesWeights[ii*4+1]=0.0;		matricesWeights[ii*4+2]=0.0;		matricesWeights[ii*4+3]=0.0;		floatIndices[ii*4+0]=boneIndice;		floatIndices[ii*4+1]=boneIndice;		floatIndices[ii*4+2]=boneIndice;		floatIndices[ii*4+3]=boneIndice;	}        // Mounting the object on the skeleton        obj.skeleton = ske;	obj.setVerticesData(matricesWeights, BABYLON.VertexBuffer.MatricesWeightsKind, false);	obj.setVerticesData(floatIndices, BABYLON.VertexBuffer.MatricesIndicesKind, false);}mounted = false;engine.runRenderLoop(function() {	if ((sword!=undefined) && (Armature!=undefined)) 	{ 		if (!mounted) {			mount(sword,Armature,"Bone");			mounted=true;		}	}	scene.render();});

And that's done. 

@TODO : unmount function

[GameMonetize]

EXCELLENT

Could you mark the question as answered?

 

PS: To unmount, just call sword.skeleton = null

[vbillet]

 

Could you mark the question as answered?

 

 

I can't mark it as answered.

Could it be mark as answered ? Yes .... But.... NO.

 

If I want to mount a bow or a crossbow on my bone, it might be difficult, because my bow need also a skeleton. This skeleton will be used for fire motion. Can we have multiple skeleton for a single mesh ?

[GameMonetize]

you can have only one skeleton but with many bones (one for bow, one for sword)

A mesh can only have one skeleton but you can change the active skeleton when you want:)