WebGL / Three.js着色器.r和.g是什么意思？

Question

So im learning shaders by example and I often see .r and .g, what do those two letters mean?

I dont even have an idea what to google since I am unaware of the terminology and use of those two letters G and R when used inside a GL shader program.

vec2 uvNoiseTimeShift = vUv + noiseScale * vec2( noiseGeneratorTimeShift.r,
                                                 noiseGeneratorTimeShift.g );

When replacing r with g the effect seems to be the same, so im not sure what those properties are for.

Answer 1

这就是所谓的swizzle运算符 ，它们返回向量的相应分量，其中r对应于x ，依此类推。