已经解决

[tea18andlife (tonycome)]

原因找到啦
bone.a/bone.c 模拟器输出都是Nan Nan!

只有这样可以
let a = bone.m00;
let c = bone.m10;

[358445267 (小趴菜)]

只有模拟器输出正确，浏览器输出错误
let a = bone.m00;
let c = bone.m10;

模拟器输出错误，浏览器输出正确
let a = bone.a;
let c = bone.c;