And no matter what, it produces grainy, noisy images with virtually no detail.

无论如何，它都会产生几乎没有细节的颗粒状、嘈杂的图像。

And initially, we start out with a noisy image, and this noise gets slowly eliminated as we compute more and more rays for the simulation.

首先，从一幅有噪声的图像开始，我们在模拟中计算的光线数量越多，噪声就会被慢慢消除。