decouple cone-size and cone-color

Hey all,

So I was using Cone plots to visualize a 3D vector field in my application, and I found that the Cone-size AND Cone-color are both a function of the norm of the u/v/w vector. It would be useful to 'decouple' this since you can scale the vector with the norm and color it according to another scalar array or vice-versa.

该 issue 涉及 Cone 图及其 u/v/w 向量分量，但没有指定文件或测试。首先定位 Cone trace 的入口点和现有的 Cone 测试，然后确认向量范数当前如何控制大小和颜色。完成标准是：大小可以使用向量范数，而颜色接受独立的标量数组，或反过来。