Overview

The V-Ray Frame Buffer is a display window for V-Ray renderings that includes a number of V-Ray-specific features. While V-Ray can render to the 3ds Max Rendered Frame Window (RFW or VFB), the V-Ray Frame Buffer has some additional capabilities:

• Switches between render elements via a dropdown of all render elements

• Keeps the image in full 32-bit floating point format

• Performs Color Corrections on the rendered image

• Allows you to choose the order in which the buckets are rendered

• Can store a list of recently rendered images and switch between them or compare them

• Applies simple Lens Effects to the rendered image

• Automatically adjusts render resolution when the VFB window is resized with V-Ray GPU and V-Ray IPR

• The ability to load progressive resumable files (.vrprog ) and the V-Ray .vrimg file format.

To use the V-Ray Frame Buffer for rendering, turn on the Enable built-in frame buffer option in the Frame buffer rollout under the V-Ray tab in the Render Setup window.

The V-Ray VFB can also be controlled with environment variables or MAXScript. See Controlling the VFB Programmatically for details.

The V-Ray VFB also has some limitations which are listed in the Notes section below.

UI Paths

||V-Ray Toolbar|| > Last VFB button

||Render Setup window|| > V-Ray tab > Frame buffer rollout > Show last VFB button

VFB Toolbar

Color Corrections

The V-Ray VFB has a robust Color Corrections control (as seen in the image in the Overview) that is enabled with its icon (shown in the table above) which is in the lower left corner of the VFB window. Color Corrections include Exposure, Hue/Saturation, Curves, etc. and are all covered here.

Render History

The V-Ray VFB keeps a history of previously rendered images, and lists each with a number, thumbnail, and textual details in the Render history. This history can be accessed through the H icon at the bottom of the VFB window. The Render history can be docked to the VFB (as shown below) or can float separately. In addition to keeping history, this feature can display two images in the VFB for comparison (as shown below), which is revealed via a sliding division line. History files are stored as .vrimg files in a user-specified folder.

VFB with docked Render history, comparing A and B images with vertical division line

The keyboard keys from 1 to 9 can be used to quickly switch between the first 9 images from the history.

Right-clicking on an image in the VFB history brings up a pop-up menu with some useful options.

Image Info window

Edit comment – Allows you to add a text comment to the image; the comment appears in the "Details" column.

Set A – Sets the image as the 'A' image when comparing two images.

Set B – Sets the image as the 'B' image when comparing two images.

Load – Loads the selected image in the VFB (same as double-clicking on the history image).

Delete – Deletes the selected image from the history. The image is moved to the system's Recycle Bin and can be restored from there if needed.

Load V-Ray Settings – Sets the current render settings to the ones used to render the selected image.

Compare V-Ray Settings – Shows a table with the differences between the settings used to render the selected image and ones currently set in the V-Ray renderer.

Image Info – Opens a window containing detailed information about the image, including, but not limited to Camera, Aperture, FOV, Target Distance, V-Ray version, render time, and also custom attributes specified in the exr metadata of VRayOptionRE render element. Have in mind that the camera values are saved in system units. Also, the vrayrevison info displayed in the list is not related to the saved .vrimg file but to the current V-Ray build installed for 3ds Max.

Manually saved .vrimg files can also be added to the History folder, but they need to be saved with all image channels in one .vrimg file to keep the complete image info.

Load Color Corrections – Loads the VFB color correction controls from the selected image.

Open Scene – Opens the rendered scene in the viewport. This option works as long as the initial file path of the scene has not changed after the render.

Reload History – Re-reads the history image list. This may be needed if the history folder is updated outside of 3ds Max (f.e. from another 3ds Max session).

Stamp Tools

VFB Shortcuts

These shortcuts navigate through the VFB image. Please note that VFB window must have the current focus for the shortcuts to have effect:

Changing the Background Color

To change the background color of the VFB, right-click on the background and select one of the options from the pop-up menu.

VFB IPR Options

View Navigation – Requires a camera view. Adjusts the view angle from the render in the VFB instead of in the viewport. Simply click and drag in the rendering area of the VFB window.

Real Zoom – When enabled, scrolling will not function in zooming the pixels of the rendered image but will move closer or further from the rendered geometry.

Pause/Resume – Pause/resume rendering.

Re-initialize – Restart rendering.

Select object – Directly select scene objects by clicking on them in the VFB rendering area. You can use the Ctrl + left mouse button keyboard shortcut instead.

Get object material – Pick a scene material from an object that is being rendered. You only need to click on that object in the VFB rendering area and the material editor will open with it. You can use the Shift + left mouse button keyboard shortcut instead.

Set focus distance – Sets the target distance for the Depth of Field effect to the location clicked in the VFB rendering area. You can use the Alt + left mouse button keyboard shortcut instead.

Note that the keyboard shortcuts work only within the VFB window.

The Undo shortcut (Ctrl+Z) for these actions will not work within the VFB window though. It only works when the focus is on the 3ds Max windows.

Pixel info – Opens the standard V-Ray VFB pixel information window.

Render Region

Render region can be used in both IPR and Production modes to isolate only part of the frame for render. Usually, when a render region is used, you would like to save the whole frame instead of the region only.

Saving single channel .exr files ignores the render region and always saves the full frame. This applies when saving the .exr from: VFB > Save to separate files/Save current channel, Render Settings > Common tab > Common Parameters > Render Output and Render Settings > V-Ray tab > Frame buffer > Separate render channels. (V-Ray ignores 3ds Max's Image Region option residing in the 3ds Max native file output dialog under Setup > OpenEXR Configuration window.)

Saving multi-channel .exr files writes just the render region data in the file by default but it can be set to save full frame instead. If the file output is saved through Render Settings > V-Ray tab > Frame buffer > V-Ray raw image file, in order to save the render region with the rest of the frame, add VRayOptionRE render element and set its exr data window option to Whole Image. Saving multi-channel .exr files from VFB > Save all channels to single file will save render region when such is enabled from the VFB. This happens even if you have selected a render region on top of the already rendered frame, without an actual region used in the rendering process. Saving full frame from VFB is performed when the VFB region is disabled.

Notes

• The V-Ray VFB does not display the G-Buffer layers (like Coverage etc.)

• The V-Ray VFB does not work with strip rendering

• The V-Ray VFB does not work with rendering to fields

• Even though you select the V-Ray VFB as your output, the 3ds Max VFB is still created and thus takes additional memory. If you want to reduce that memory, you need to uncheck the Get resolution from MAX option, set the 3ds Мax resolution to a low value like 100 x 100, and then select your real output resolution in the V-Ray VFB options.

• If you have selected an output image file from the Common tab of the Render Scene dialog, V-Ray will fill out the 3ds Max RFW, and this will be saved as your image. If you want to save the V-Ray VFB instead, you should use the Split render channels or Render to V-Ray raw image file option of the V-Ray VFB.

• The OpenEXR file format is an open file format for high dynamic range images originally developed by Industrial Light and Magic. The official site of the OpenEXR file format is http://www.openexr.com/

• When using the IPR right-click options, the primary 3ds Max window needs the cursor focus to use Ctrl+Z to Undo.

• If Lens Effects or the VRayDenoiser render element are enabled, then the RGB Color channel is saved with the name RGB_color and the effectsResult channel is saved as effectsResult when saving all channels from VFB.

• If an 8-bit file is saved through the VFB or the Render Output / Save image settings, the sRGB gamma curve is embedded and the image appears as in the frame buffer when loaded in an external image viewer. If a 32-bit (exr, hdr, tif) image is saved, it remains linear and relies on the external image viewer to handle the gamma.

• The VFB test resolution is ignored for command-line rendering and Backburner jobs. Test Resolution button is inactive in IPR if Fit resolution to VFB is enabled.