Overview

The Utilization rollout gives access to the Progressive render settings in both production and IPR modes. You can control the ray size(s), its trace depth and set a low thread priority of the rendering.

UI Path

||Render Setup window|| > Performance tab > Utilization rollout

Parameters

Rays per pixel – The number of rays that are traced for each pixel during one image pass in Production rendering mode. The greater the value, the smoother the picture from the very beginning of the rendering with GI, but interactivity might be significantly diminished. Increasing this value also reduces the amount of data transferred from the render servers back to the client machine when using Distributed Rendering.

IPR Rays per pixel – The number of rays traced for each pixel during one image pass in IPR mode.

Rays bundle size – Controls the number of rays that are sent to the render servers for processing. When using Distributed Rendering, smaller values cause more frequent client/server communication with smaller network packets, thus decreasing the speed of the renderer but increasing the interactivity. Conversely, larger values increase the speed of the renderer but decrease interactivity. Note that this number is not the exact amount of rays, but is proportional to it. It is not recommended to increase this value beyond 512.

Undersampling – When enabled, IPR starts rendering the image at a lower resolution in order to speed up the initial preview. Later the image is rendered at its final resolution.

Trace depth – Represents the maximum number of bounces that are computed for reflections and refractions. The individual material reflection/refraction depth settings are still considered, as long as they don't exceed the value specified here.

Low GPU thread priority – When enabled, V-Ray tries to lessen the load on GPUs working on displaying graphics to the monitor(s) in order to give them more resources to complete other processes and tasks for the OS. This is done by internally using a lower value for Rays bundle size for those GPUs with attached displays (Rays per pixel is still the same for all GPUs). This can affect the overall performance, and the render speed might be reduced. It is recommended to utilize a separate GPU for the display, if possible.