Table of Contents

This page provides information on the Frame buffer rollout under the V-Ray tab.


The settings in the Frame buffer rollout control various aspects of the V-Ray Frame Buffer, a display window for renderings optimized for V-Ray.

When rendering in 3ds Max without V-Ray, renderings appear in the 3ds Max frame buffer. The V-Ray Frame Buffer works similarly in that it displays the rendered image as it is generated, and also provides additional tools specific to V-Ray.

Due to technical reasons, the original 3ds Max frame buffer is still created at render time even if rendering to the V-Ray Frame Buffer. However, when the V-Ray Frame Buffer is enabled, V-Ray does not render any data to the 3ds Max frame buffer. To preserve memory consumption when using the V-Ray Frame Buffer, the following settings are recommended:

  • Under the Common tab Output Size section in the Render Setup window, set both Width and Height to low values such as 100.
  • Under the Common tab Render Output section, disable the Rendered Frame Window option.
  • In the V-Ray Frame Buffer rollout (described on this page), disable Get resolution from MAX and enter the desired Width and Height values along with any other needed information such as Image aspect.

UI Path: ||Render Setup window|| > V-Ray tab > Frame buffer rollout (Renderer set to V-Ray)


Enable built-in frame buffer – Enables the use of built-in V-Ray Frame Buffer. When disabled, renderings appear in the 3ds Max frame buffer instead.

Memory frame buffer – Creates a V-Ray frame buffer and uses it to store color data that you can observe while rendering and afterwards. If you wish to render really high resolutions that would not fit into memory or that may eat up a lot of your RAM not allowing for the scene to render properly, you can turn this feature off and use only the Render to V-Ray raw image file feature.

Show last VFB – Opens the V-Ray VFB if it has already rendered and then closed. The same can also be achieved with the showLastVFB() MaxScript method of the V-Ray renderer.

Reset VFB position – Returns the V-Ray VFB to its original location in case its position has been previously changed.

Get resolution from 3ds Max – Causes the V-Ray VFB to take its resolution from the 3ds Max common render settings.

Image aspect – Specifies the image aspect for the rendered image in the VFB when Get resolution from Max is disabled

Pixel aspect – Specifies the pixel aspect for the rendered image in the V-Ray frame buffer when Get resolution from Max is disabled.

Width – Specifies the width of the image when Get resolution from Max is disabled.

Height – Specifies the height of the image when Get resolution from Max is disabled.

Swap – Swaps the values of Height and Width parameters.

Preset – Selects a resolution for the V-Ray VFB from a list of resolution presets when the Get resolution from 3ds Max is disabled.

V-Ray raw image file – When enabled, V-Ray directly writes to disk the raw image data as it is being rendered. It does not store any data in the RAM, so this feature is very handy when rendering huge resolutions for preserving memory with Memory frame buffer disabled. To see what is being rendered, turn on the Generate preview setting. See the Save V-Ray Image File section for more information. 

If you are using the Progressive Image Sampler, the image is kept in the memory during the rendering. You need to manually stop the rendering, or set a limit and wait for the rendering to complete before the .vrimg is saved.

Generate preview – Creates a small preview of what is being rendered. If you are not using the V-Ray memory frame buffer for conserving memory (i.e. Render to memory frame buffer is disabled), you can use this feature to see a small image of what is being actually rendered and stop the renderer if there is anything that looks wrong.

Separate render channels – Saves the channels from the VFB into separate files. Use the Browse... button to specify the file. This option is available only when rendering to a memory frame buffer. If rendering is done only to a raw image file, the render channels can be extracted from that file after rendering is complete. If the VRayDenoiser render element is enabled, the RGB channel is saved with the text origRGB appended to the filename, and the effectsResult channel has the text RGB_color appended to it.

Separate folders – Saves each render element to a separate folder based on its name.

Expand # to frame number – (enabled by default) Disable it to stop V-Ray from replacing the # symbol with frame numbers for separate render channels. 

Save RGB and Save Alpha – Disables saving of the RGB and Alpha channels respectively. This can be useful if you only want to generate other render channels. Note that V-Ray still generates the RGB and Alpha channels; however, they are not saved.

Save VFB color corrections to render elementsWhen enabled, saves the VFB color correction to render elements.

Resumable rendering – If there is a resumable file existing for the current frame, the rendering is resumed from it. Otherwise, a new render is started and resumable files are saved. If the rendering is already complete, the frame is skipped and the next one (if any) is started. For more details, please see the Resumable Rendering tutorial page.

Note: All saving formats are supported by the VFB (Render Setup > V-Ray tab > Frame Buffer) and 3ds Max output (Render Setup > Common tab > Render Output). Resumable information is stored in additional .vrimg or .vrprog files. Resuming a render with bucket sampling uses and creates additional .vrimg files. Resuming a render with progressive sampling uses and creates separate .vrprog (progressive resumable) files. For instance, if resumable rendering is enabled when rendering to a PNG file format using the progressive sampler, resumable information will be saved as a .vrprog file along with the output PNG.

Autosave Interval (min) – Specifies an interval in minutes for saving resumable files during rendering. This usage applies only to Progressive sampling; Bucket renderings are saved on every completed bucket. A value of 0 disables autosaving during rendering and resumable files are saved only at the end of the rendering.

Delete resumable data from completed frames – When enabled, the resumable file is deleted automatically if the frame is completed successfully. This applies for additional .vrimg or .vrprog files, it doesn't apply when the output image file is .vrimg.

Save V-Ray Image File

The Save V-Ray Image File window is accessible when the V-Ray raw image file option is enabled.

File Name – Specifies the name of the file. 

Save as type – Chooses as what type of file to save the image. You can specify either a .vrimg, .vrst, or an .exr file for output:

If you specify a .vrimg extension, the resulting file can be viewed through the File > View image... menu of 3ds Max or loaded in V-Ray Frame Buffer. It can be converted to an OpenEXR file with the help of the VRImg to OpenEXR Convertor tool.

If you specify an .exr extension, V-Ray writes out a tiled OpenEXR file that can be used directly by 3ds Max or other compositing applications. The file contains all render elements for the image.

The .vrst extension denotes V-Ray's native deep image file format. It stores similar information as a deep .exr image file. 

For either file type, if Lens Effects or the VRayDenoiser render element are enabled, the resulting file contains both the RGB Color channel and effectsResult channel.

EXR/VRST 32-bit output – When enabled, the file is saved in a 32-bit output. Note that .vrimg files always contain 32-bit data. 

Deep EXR – Saves the .exr file with a deep output. 

The Bucket image sampler calculates the deep data file properly. If Progressive image sampler is used instead, then no .exr deep output file is saved.

Dot-delimited frame number – When enabled, adds a dot between the file name and the frame number suffix in case an animation is rendered. 

Save VFB color corrections to RGB channel – When enabled, saves all applied VFB color corrections to the RGB channel of the output image. This does not apply to the sRGB, Gamma 2.2, and ICC display corrections. OCIO, LUT, and Background Image corrections are saved if this is explicitly specified in their VFB rollouts.

Color correction layers are only saved to .exr and .vrimg files written through V-Ray's own output. The output in Render Setup > Common tab is written by 3ds Max so .exr files saved from there do not have Layers saved.

When saving layers to an exr/vrimg file, V-Ray writes a flag indicating whether the color corrections are baked in the RGB channel. For example, if you save an exr from the VFB File menu > Save all image channels to single file option, V-Ray creates an .exr file with corrections baked in. It also saves the layers as metadata and the flag that corrections are baked in. When loading images into the Frame Buffer, V-Ray checks if the image has corrections baked (using the flag), and if such are found, the layers are not loaded because this causes double correction.

If you want to keep the layers that come with the Max scene, turn the Auto Load Layers option off from VFB > Options > History tab. If you want to load layers from an external image, enable the Auto Load Layers option and check how you save those images.

Save Cryptomatte separately – When enabled, saves the Cryptomatte channels as a separate EXR file. Keep in mind that this option is intended to work only when Save as type is OpenEXR.

Additional options for saving .exr raw output are available through the VRayOptionRE render element.  

Hidden Parameters

There are some additional parameters of the VFB which are not available in the interface but are accessible through MAXScript. These may be useful in certain situations. Below are listed the MaxScript names of these parameters.

output_renderType – Overrides the render type, specified in the 3ds Max settings. Possible values are:

– use 3ds Max render type (default) 
– render the full image 
– region rendering 
– crop rendering 
– blow-up rendering

output_regxmin – The left coordinate (in pixels) of the region to render (for region/crop/blow-up rendering)

output_regxmax – The right coordinate (in pixels) of the region to render (for region/crop/blow-up rendering)

output_regymin – The top coordinate (in  pixels) of the region to render (for region/crop/blow-up rendering)

output_regymax – The bottom coordinate (in  pixels) of the region to render (for region/crop/blow-up rendering)

Note that the region coordinates are always relative to the resolution specified in Output Size section of the 3ds Max Render Setup window. They are rescaled proportionally to fit the actual VFB resolution, if Get resolution from Max is disabled.


  • For information on render region and saving .exr files with render region, see the V-Ray Frame Buffer page.
  • If rendering with V-Ray Standalone, use the -deleteResumableFileOnSuccess=1 command to automatically delete the resumable file if the frame is completed successfully. This applies to additional .vrimg or .vrprog files, and not when the output image file is .vrimg. The default command value is 0, which keeps the resumable file.
  • VRIMG is a Chaos proprietary file format used by the V-Ray Frame Buffer to store the rendered image incrementally (bucket by bucket) while rendering in full floating-point format, with all available render elements. It is used as a render output but it is not recommended to use it as a texture file format. VRIMG contains metadata, i.e. render statistics. It supports dynamic bucket size. VRIMG can be saved just as any other image format – it can either be the render output format or it can be saved from the VFB.