On the Sampling tab, you can adjust controls that affect your render quality. Adjust:
• ray trace max depth - to set the maximum depth of the view rays PrmanRender uses to trace your scene and make render calculations.
• pixel samples - to set the number of samples to render per pixel. Having more samples increases your render quality, but also increases render time.
• filter - to select a texture sampling filtering algorithm. For more information on the different options, see Choosing a Filtering Algorithm.
• antialiasing filter - to select an antialiasing filter: box, triangle, catmull-rom, sinc, gaussian, mitchell, separable-catmull-rom or blackman-harris.
• antialiasing filter size - to select the size of the antialiasing filter.
• shading rate - to set the shading calculation for primitives. This value, along with pixel samples, directly affects your rendering time and the final quality of your results. A small shading rate value means your render takes more time, but the quality is very high. A large value on the other hand means your render is faster, but the final quality is not as good.