Engine – Switches between the CPU, CUDA(GPU), and RTX(GPU) rendering engine.

The devices used by the GPU engine to perform the raytracing calculations, can be specified via the arrow on the right .

The Computer CPU is also listed as "C++/CPU" in the CUDA device list and can participate in rendering (Hybrid rendering). For more information, see the Hybrid Rendering section below.

Sampler – Selects the image sampler type. For more information on how the Sampler works, see the Sampler page. 

Progressive – This is the default image sampler set in V-Ray for Revit. It renders the entire image progressively in passes.

Bucket – This sampler takes a variable number of samples per pixel based on the difference in intensity between the pixel and its neighbors.

Global Illumination allows for selecting a primary and secondary GI engine.

There are several ways to combine primary and secondary GI engines in V-Ray for Revit.

1. Brute Force + Brute Force 
2. Brute Force + Light Cache 
3. Irradiance Map + Light Cache 
4. Irradiance Map + Brute Force 

GI Depth – Specifies the number of light bounces that will be computed. GI Depth will also be used to calculate Interactive rendering GI Depth.

Ambient Occlusion – Enables or disables ambient occlusion. The multiplier controls the amount of ambient occlusion. A value of 0.0 produces no ambient occlusion, whereas higher values make the ambient occlusion effect more prominent.

For more information on Global Illumination, see the Indirect Illumination Reference page. 

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, as long as they don't exceed the value specified here.

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

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 may be significantly diminished. Increasing this value also reduces the amount of data transferred from the render servers back to client machine.

Undersampling – When set to a value greater than 0, during interactive updates, the image is rendered initially at a lower resolution in order to speed up the preview of the updates. Once you stop updating the model, the image is rendered at its final resolution The optimal value for Undersampling is the default one. 

Adaptive Lights  – Optimizes the sampling of lights in scenes with many lights. 

Adaptive Dome Light – When enabled, optimizes the sampling algorithm for the Dome Light which results in faster rendering. Note that Light Cache has to be selected as a secondary GI engine in order for this optimization to work.

Use Revit Far Clip – When enabled, V-Ray uses the Revit camera Far Clip Offset. 

Use Trace Depth in Production – When enabled, the Global Trace Depth is used for all materials. When disabled, the Trace Depth defined by each material is used. When rendering in Interactive/CPU, this setting is ignored and the Global Trace Depth is always used.

Bucket Size – Determines the maximum bucket width in pixels when the Sampler is set to Buckets. 

This affects the tessellation of the geometry in each of the quality presets ranging from 0-15. Higher values result in geometry from Revit having more polygons. Lower values decrease render times but result in round geometry appearing to be more jagged in appearance. Values at and close to zero create odd situations such as round columns appearing to only have 4 or so sides.

 When Auto-Save is Enabled V-Ray will save automatically completed renderings to a specified location. 

File Path – Browse for a folder where completed renderings will be saved.

File Type – Select the file format of the auto-saved images.

Image Options

Alpha – Determines how the Alpha channel will be handled. This option is available for the following formats: .png, .tga, .sgi, .exr, .pic, and .tif. 

No Alpha – No Alpha channel will be saved. The background will be visible even if the output image format supports transparency. 
Include Alpha – The Alpha channel will be saved as image Alpha or Transparency depending on the file format. 
Separate Alpha – The Alpha channel will be saved as a separate file.

Compression Level – Specifies the image compression level for the .png file type.

Bits per Channel – Specifies the amount of data per channel for the .png, .sgi, .exr, and .tif file types. The following options are possible depending on the file type:

8 bits
16 bits