Blender Json exporter export wrong skinning data when there are multiple meshes in one Armature.

[WiltonAlger]

Often it is required to have multiple meshes under the same armature. In my case, one part of the mesh need to use the mirror modifier and the other part does not. (hair and body) I know the exporter can only export one selected mesh a time, that is fine with me. When exporting the body (export pretty much everything including keyframe animations) everything works fine. When I want to export the hair, I only want to export the relevant mesh data as the threeJS exporter is slow when there are many animation actions. Thus I disable skeletal animations when exporting hair. The problem is that the exported .bones does not match up with the skinIndices. For testing, my hair mesh only use the "head" bone to deform which is the 4th bone in the exported .bone data for hair mesh, but is exported as bone index 22 in the skinIndices Data. Bone index 22 is the exported "head" bone for the body mesh.

Relevant output for the hair mesh:

{
"bones": [{
"pos": [0,6.084,-0],
"parent": -1,
"rotq": [0,0,0,1],
"name": "Waist"
},{
"pos": [0,0.636,-0],
"parent": 0,
"rotq": [0,0,0,1],
"name": "stomach"
},{
"pos": [0,0.9326,0.2337],
"parent": 1,
"rotq": [0,0,0,1],
"name": "torso"
},{
"pos": [-0,1.6779,-0.3728],
"parent": 2,
"rotq": [0,0,0,1],
"name": "neck"
},{
"pos": [0,0.6539,0.0287],
"parent": 3,
"rotq": [0,0,0,1],
"name": "head"
},{
"pos": [0,0.0113,0.4274],
"parent": 4,
"rotq": [0,0,0,1],
"name": "mouth_bottom"
}
...
],
"skinIndices": [22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,22,0,0,0,...]

Relevant output for the body mesh:

{
"bones": [{
"scl": [0.9968, 1, 1],
"pos": [0.5621, -0.0236, -0.5847],
"parent": -1,
"rotq": [0, 1, -0, -0.0055],
"name": "IK_foot_L"
}, {
"scl": [1, 1, 1],
"pos": [-0, -0, -1.0372],
"parent": 0,
"rotq": [0.0341, 0.9542, -0.2971, -0.0075],
"name": "IK_football_L"
}, {
"scl": [1, 1, 1],
"pos": [0, -0, -0.7606],
"parent": 1,
"rotq": [-0.2915, -0.0237, -0.0171, 0.9561],
"name": "IK_ankle_L"
}, {
"scl": [1, 1, 1],
"pos": [0.0277, 0.0041, -1.8971],
"parent": 0,
"rotq": [0.7143, -0.0109, 0.0196, 0.6995],
"name": "IK_toe_L"
}, {
"scl": [1, 1, 1],
"pos": [0.0435, 3.8409, -3.648],
"parent": 0,
"rotq": [0, -0.0055, -0, 1],
"name": "IK_pole_knee_L"
}, {
"scl": [0.9968, 1, 1],
"pos": [-0.5621, -0.0236, -0.5847],
"parent": -1,
"rotq": [0, 1, -0, 0.0055],
"name": "IK_foot_R"
},

...
"scl": [1, 1, 1],
"pos": [-0, -0, -0.636],
"parent": 10,
"rotq": [-0.1225, -0, 0, 0.9925],
"name": "stomach"
}, {
"scl": [1, 1, 1],
"pos": [-0, -0, -0.9615],
"parent": 19,
"rotq": [0.23, -0, -0, 0.9732],
"name": "torso"
}, {
"scl": [1, 1, 1],
"pos": [-0, -0, -1.7188],
"parent": 20,
"rotq": [-0.1309, 0, 0, 0.9914],
"name": "neck"
}, {
"scl": [1, 1, 1],
"pos": [-0, 0, -0.6545],
"parent": 21,
"rotq": [0.0343, -0, 0, 0.9994],
"name": "head"
},

In fact I just noticed the exported bone data are completely off too. Please advise what to do.

[mrdoob]

If this is a bug you should share the .blend file too.

[Mugen87]

The JSON Blender exporter has been removed with R93 (#14117).

Also see: https://threejs.org/docs/#manual/introduction/Loading-3D-models