This page provides information on the Frame buffer rollout under the V-Ray tab in the Render Setup window.

Page Contents ×


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 will 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






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 – If you have rendered to the V-Ray VFB but have closed it, this button opens it again. The same can also be achieved with the showLastVFB() MaxScript method of the V-Ray renderer.

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.

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. If you wish to see what is being rendered, you can 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 – Allows the user to save 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 Lens Effects or the VRayDenoiser render element are 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 – Save each render element to a separate folder based on its name.

Expand # to frame number – This option is 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 – Allows the user to disable 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. 

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.


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 – Choose 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 will write 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 – Enable this option to save the file in a 32-bit output. Note that .vrimg files always contain 32-bit data. 

Deep EXR – Enable this option to save the .exr file with a deep output. 

Dot-delimited frame number – Enable this option to add a dot between the file name and the frame number suffix in case an animation is rendered. 

Save VFB color corrections to RGB channel – Enable this option to save 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.

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 – This allows you to override 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 dialog. 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.