solved Blender 'Shape Keys' > Babylon 'morphTargetManager'

[babbleon]

Hello, 

I'm posting this partly to help anyone else who has struggled with this, but also to ask if I am doing something wrong / if this is a bug in the exporter.

When I export a mesh from Blender with 'Shape Keys', I have to create two Keys in addition to the Basis for it to work in Babylon.

One Key + basis: https://www.babylonjs-playground.com/#0XATER#1

Two keys + basis: https://www.babylonjs-playground.com/#0XATER

 

[JCPalmer]

Well, I see that the key is added

The only thing I can think of on the exporter side is that basis is used for the data for the first key.  Look in the export & see if the data for the positions is the same as key 1.  If it is different, then I am inclined to think the export is fine & problem downstream.

[babbleon]

Here's the positions for the vertices of mesh & targets for Key 1 (this is the one with only one shape key).

one shape key

Mesh vertex positions:

[0.5,0,0.25,-0.5,0.38,0.25,0.5,0.38,0.25,0.5,0,-0.25,-0.5,0,0,0.5,0,0,0.5,0.76,0,-0.5,0.76,-0.25,0.5,0.76,-0.25,0.5,0.38,-0.25,0.5,0.38,0,-0.5,0.38,-0.25,-0.5,0,-0.25,-0.5,0.38,0,-0.5,0,0.25,0.5,0.76,0.25,-0.5,0.76,0
,-0.5,0.76,0.25]

Target vertex positions for 'Key 1':

[0.5,0,0.25,-0.5,0.38,0.25,0.5,0.38,0.25,0.5,0,-0.25,-0.5,0,0,0.5,0,0,0.5,0.76,0,-0.5,0.76,-0.25,0.5,0.76,-0.25,0.5,0.38,-0.25,0.5,0.38,0,-0.5,0.38,-0.25,-0.5,0,-0.25,-0.5,0.38,0,-0.5,0,0.25,0.5,0.76,0.25,-0.5,0.76,0
,-0.5,0.76,0.25]

...the same.

This may be something for @V!nc3r to add to the docs until it's sorted.

[JCPalmer]

I just looked at the code & cannot see where this is wrong, so I made my own cube, added a basis & key.  Went into edit mode (while the key was selected) & colapsed a face in.  When I export, I get different values for the positions & target positions:

"meshes":[{"name":"Cube","id":"Cube","materialId":"shapekey.Material","billboardMode":0,"position":[0,0,0],"rotation":[0,0,0],"scaling":[1,1,1],"isVisible":true,"freezeWorldMatrix":false,"isEnabled":true,"checkCollisions":false,"receiveShadows":false,"pickable":true,"tags":""
,"positions":[1,-1,-1,-1,-1,1,1,-1,1,-1,1,1,1,1,-1,1,1,1,-1,-1,-1,-1,1,-1]
,"normals":[0.577,-0.577,-0.577,-0.577,-0.577,0.577,0.577,-0.577,0.577,-0.577,0.577,0.577,0.577,0.577,-0.577,0.577,0.577,0.577,-0.577,-0.577,-0.577,-0.577,0.577,-0.577]
,"indices":[0,1,2,3,4,5,5,0,2,4,6,0,6,3,1,2,3,5,0,6,1,3,7,4,5,4,0,4,7,6,6,7,3,2,1,3]
,"subMeshes":[{"materialIndex":0,"verticesStart":0,"verticesCount":8,"indexStart":0,"indexCount":36}]
,"instances":[],"morphTargetManagerId":535126}
],
"morphTargetManagers":[{"id":535126
,"targets":[{"name":"Key 1"
,"positions":[-0.7202,-1,-1,-1,-1,1,-0.7202,-1,1,-1,1,1,-0.7202,1,-1,-0.7202,1,1,-1,-1,-1,-1,1,-1],"influence":0}]}],

Cannot reproduce.

[babbleon]

Okay... I see the issue. When you export with the 'Key 1' value set to 1.000 it exports the same positions for meshes & targets, seems to work when set to any other value.

[JCPalmer]

I think it is more accurate to say that each morph target is always exported with the same values.  The positions themselves are not directly exported in the first place.  A temp copy with all modifiers including current shapekey settings is made, & that is what gets exported.  This is very powerful.  You might have Mirror modifier for making a perfectly symmetrical mesh with only doing half the work.  You do not to ^{HAVE TO} apply your modifiers to do an export, since it would wreck more development.  Probably best to store all your shapekeys @ 0 in the .blend file to get your mesh exported without any influences per-applied.