V-Ray RT (Real-Time) is Chaos Group’s interactive rendering engine that can utilize both CPU and GPU hardware acceleration to see updates to rendered images in real time as objects, lights, and materials are edited within the scene.

Use RT Engine – When enabled, V-Ray RT used.

Use GI – When enabled, V-Ray RT rendering with GI.

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

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

GI depth – The number of bounces for indirect illumination. Other GI settings (i.e.. whether GI is enabled or disabled) are taken from the production V-Ray renderer. The GI depth is disabled if the secondary GI engine is the light cache – in that case, V-Ray will configure the GI bounces automatically.

Perfomance

CPU Ray bundle size – Controls the number of rays that are sent to the V-Ray RT render servers for processing. When using distributed rendering, smaller sizes cause more frequent client/server communication with smaller network packets, thus decreasing the speed of the renderer but increasing the interactivity. Conversely, larger sizes 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.

CPU Rays per pixel – The number of rays that are traced for each pixel during one image pass. 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.

GPU Ray bundle size – Controls the number of rays that are sent to the V-Ray RT render servers for processing. When using distributed rendering, smaller sizes cause more frequent client/server communication with smaller network packets, thus decreasing the speed of the renderer but increasing the interactivity. Conversely, larger sizes 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.

GPU Rays per pixel – The number of rays that are traced for each pixel during one image pass. 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.

Undersampling – When enabled, V-Ray RT 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.

Coherent tracing (RPP) – When enabled, V-Ray RT will attempt to spawn secondary rays (GI, reflection etc) in similar directions in order to improve rendering speed on certain GPUs.

Progressive Sample Per Pixel – When enabled, V-Ray RT starts rendering the image with a lower Rays per pixel value and then progressively increases it. This speeds up the initial preview of the image.

Rendering

Max Render Time (min) – Specifies the maximum time (in minutes) for refining the image.

Max Paths per Pixel – Specifies the maximum samples per pixel for refining the image.  V-Ray performs adaptive sampling on the image, trying to put more samples into areas that have more noise.

Adaptive Sampling

Max. noise – A threshold that determines when to stop refining a pixel. Higher values allow more noise in the image, while lower values try to reduce the noise. A value of 0.0 traces the entire image unconditionally.

Show mask – When this option is turned on, the displayed images in the frame buffer will be marked the place where at the moment the sample is produced adaptation.

Engine

RT Type – Specifies the back-end for the RT engine. The possible values are:

  • CPU – The CPU engine is used. This engine does not require a graphics card and supports many of the regular V-Ray renderer features, including procedural textures and complex materials.
  • OpenCL (single kernel) – A GPU engine based on OpenCL is used. This engine uses graphics cards that support OpenCL and can be very fast depending on the hardware, but has somewhat limited abilities with regards to shaders. The OpenCL and CUDA engines have the same set of capabiltities, but for nVidia GPUs it is recommended to use the CUDA engine.
  • CUDA (single kernel) – A GPU engine based on the nVidia CUDA platform. This engine uses nVidia graphics cards that support CUDA and is the recommended engine for nVidia GPUs. Like the OpenCL engine, it can be very fast depending on hardware, but has limited abilities with regards to shaders. The OpenCL and CUDA engines have the same set of capabilities. The recommended choice for nVidia GPUs.

Resize Tex for GPU – Enable this option to resize high-resolution textures to a smaller resolution in order to optimize memory usage. This parameter is only effective when Type is set to Open CL (single kernel) or CUDA (single kernel).

GPU Tex Size – When GPU Tex Size is enabled, this value specifies the resolution to which the textures will be resized.

Format – allows you to choose between 16-bit (half float) and 32-bit (full float) precision.

Stereo

Enable – enables the rendering of a stereoscopic image

Stereo Eye distance – the distance between the two virtual stereo cameras. The cameras are always focused at the camera target for the current view.

Stereo Focus – specifies the focus method for the two views. Possible values are:

  • None – both cameras have their focus points directly in front of them
  • Rotation – the stereoscopic effect is achieved by rotating the left and right views so that their focus points coincide at the distance from the eyes where the lines of sight for each eye converge called fusion distance.
  • Shear – the orientation of both views remain the same but each eye’s view is sheared along z so that the two frustums converge at the fusion distance.

Expert

Always disable auto names – XXX.

Export System – XXX.