Cannot get a simple (manual) bones deformation working

[Shumberg]

Hello all.

I am trying to get a simple manual bones animation test working, and I think I have all the pieces going, but I see no deformation. The basic idea is I have a mesh which stands about 250 units tall, and I am trying to make a very simple 'spine' (2 bones) generate a smoothish z-bend, using very simple height-based weighting on a pair of bones:

 

//// The mesh data is being brought in from a microservice - the basic mesh data is fine;
//// My weighting looks reasonable.

            var obj = new BABYLON.Mesh(objName, scene);
            obj.position = BABYLON.Vector3.Zero();
            obj.setVerticesData(BABYLON.VertexBuffer.PositionKind, data[objName].model.P, false, 3);
            obj.setVerticesData(BABYLON.VertexBuffer.NormalKind, data[objName].model.N, false, 3);
            obj.setVerticesData(BABYLON.VertexBuffer.UVKind, data[objName].model.uv, false, 2);
            obj.setIndices(data[objName].model.indices);

            var tmpAttr = []
            for (var i = 0; i < data[objName].model.P.length; i+=3) {
                var nHt = Math.abs(data[objName].model.P[i+1]) / 250.0;
                tmpAttr.push(1.0 - nHt);
                tmpAttr.push(nHt);
                tmpAttr.push(0.0);
                tmpAttr.push(0.0);
            }
            obj.setVerticesData(BABYLON.VertexBuffer.MatricesWeightsKind, tmpAttr, false, 4);

            tmpAttr = [];
            for (var i = 0; i < data[objName].model.P.length; i+=3) {
                tmpAttr.push(0.0);
                tmpAttr.push(1.0);
                tmpAttr.push(0.0);
                tmpAttr.push(0.0);
            }
            obj.setVerticesData(BABYLON.VertexBuffer.MatricesIndicesKind, tmpAttr, false, 4);

//// ...elided stuff...

            var skel = new BABYLON.Skeleton(objName + "Skeleton", objName + "Skeleton", scene);
            var par = null;
            var nBones = 2;
            var mat = new BABYLON.Matrix.FromValues(1.0, 0.0, 0.0, 0.0,
                                                    0.0, 1.0, 0.0, 0.0,
                                                    0.0, 0.0, 1.0, 0.0,
                                                    0.0, 0.0, 0.0, 1.0);
            console.log(mat);
            for (var i = 0; i < nBones; i++) {
                var bone = new BABYLON.Bone(objName + "Bone" + i, skel, par, mat);
                var boneAnim = new BABYLON.Animation("Bone" + i + "Animation", "matrix", 30,
                                                     BABYLON.Animation.ANIMATIONTYPE_FLOAT,
                                                     BABYLON.Animation.ANIMATIONLOOPMODE_CYCLE);
                var keys = [];
                keys.push({frame: 0, value: mat});
                keys.push({frame: 30, value: mat});
                boneAnim.setKeys(keys);
                bone.animations.push(boneAnim);
              
                par = bone;
                mat = BABYLON.Matrix.FromValues(1.0, 0.0, 0.0, 0.0,
                                                0.0, 0.7, -0.7, 125.0 * (i + 1),
                                                0.0, 0.7, 0.7, 0.0,
                                                0.0, 0.0, 0.0, 1.0);


            }
            obj.skeleton = skel;
            objCopy.skeleton = skel;
            console.log(skel);
            scene.beginAnimation(skel, 0, 30, true);

 

 

The basic (static) display of my geometric data is working fine - I just see no deformation (i.e., my rather boring/static animation (looking for a 45 deg z bend halfway up the character)). I am using a custom ShaderMaterial, so I also tried adding "matricesWeights" and "matricesIndices" to the attributes list in the material constructor (I believe the deformations are being handled in a magic geometry shader (??)), but that didn't work either.

Most of the bones examples are more oriented towards having the char/rig imported from a DCC app - I couldn't find any "from scratch" examples.

Thanks in advance,

Chris