The Renderer rollout provides convenient access to common Rendering functions such as choosing the render devices or turning on and off V-Ray Interactive and Progressive mode. You are also able to choose from several Quality presets as well.
UI path: ||V-Ray Asset Editor|| > Settings > Renderer
Engine – Switches between CPU and GPU rendering engine. GPU enabled unlocks the menu on the right, where you can select which CUDA device(s) to perform the raytracing calculations or combine them for Hybrid Rendering. The Computer CPU is also listed as "C++/CPU" in the CUDA device list.
Interactive – Enables the interactive rendering engine to see updates of rendered images while objects, lights, and materials are being edited within the scene. Interactive rendering works only in Progressive mode.
Progressive – Render the entire image in iterations. You can see an image very quickly, and then let it refine for as long as necessary as additional passes are being computed.
Quality – Slides through different preset values that will automatically adjust the Raytrace Global Illumination settings.
Denoiser – Enables the Denoiser Render Element. Denoiser toggle is active only in non-Interactive render mode.
Hybrid Rendering with CPUs and the CUDA Engine
Starting in 3.60, V-Ray GPU can perform hybrid rendering with the CUDA engine utilizing both the CPU and NVIDIA GPUs. V-Ray can now execute the CUDA source on the CPU, as though the CPU was another CUDA device. To enable the hybrid rendering mode, simply enable the C++/CPU device from the list of CUDA devices.
The hybrid rendering mode does not require any special drivers. Furthermore, you can use the CPU as a CUDA device even if you don't have an NVIDIA GPU and/or NVIDIA drivers installed. Meaning, this mode can be used on computers that don't even have GPUs. The hybrid render engine running on a CPU supports the same features as the regular V-Ray GPU CUDA engine.
Interactive GPU OpenCL rendering mode is currently not supported.