Hi everyone, I found something interesting,
I just export a polygon plane and polygon sphere both were triangulated.
In DAE file i only see
<triangles material=“initialShadingGroup” count=“200”>
<input semantic=“VERTEX” source="#pPlaneShape1-vertices" offset=“0”/>
0 1 11 1 12 11 1 2 1…</p>
</triangles>
But the normal array is above, here maybe missing such line below
<input semantic=“NORMAL” source="#pPlaneShape1-normals" offset=“1”/>
and the array should be twice big.
Is COLLADA smart enough to know we do not need to ouput normal index array so we can share the vertex index array ?