This page provides an overview of the V-Ray Frame Buffer.
In addition to rendering to the Maya® Render View, V-Ray has a V-Ray specific frame buffer, which has some additional capabilities:
- View all render elements in a single window and switch between them easily.
- Keeps the image in full 32-bit floating point format.
- Perform color corrections on the rendered image.
- Choose the order in which the buckets are rendered.
- Store a list of recently rendered images and switch between them easily.
- Apply lens effects to the rendered image.
- The ability to load progressive resumable files (.vrprog ) and the V-Ray .vrimg file format.
To use the V-Ray VFB, enable the Use V-Ray VFB check box under the Render View rollout in the Common tab of the Render Settings window.
To control the V-Ray Frame Buffer programmatically (with MEL), see the Controlling the VFB Programmatically page.
The V-Ray frame buffer with its render history and color correction windows docked
||Render Settings window|| > Common tab > Render View rollout
|This drop-down gives access to render elements rendered for the scene. The selected render element is displayed in the VFB. By default, the RGB color and Alpha render elements are available. Any additional render elements that have been added to the scene will also appear in the drop-down.|
This part of the toolbar sets the currently selected channel, as well as the preview mode. Choose which channels to see with the help of the buttons. You can also view the rendered image in monochromatic mode.
The RGB Button switches the current channel to RGB color by default. When effects are applied, such as the or Lens Effects, the button will toggle between the effectsResult channel and RGB color channel.
|Saves the image into a single file. If a multi-channel type file is used (.exr, .vrimg) all the render elements will be saved in the same file.|
|Saves all the render elements into separate files.|
|Opens an image file to be previewed in the V-Ray Frame Buffer.|
|Clears the contents of the frame buffer. Sometimes helpful when starting a new render to prevent confusion with the previous image.|
|Copies the current V-Ray frame buffer to the Maya Render View.|
Forces V-Ray to render the closest bucket found to the mouse pointer, when using the bucket sampler. If the progressive sampler is used, V-Ray samples the closest pixels next to the mouse pointer. Drag the mouse over the V-Ray frame buffer while rendering to change what part of the image is done first. You can turn this on and of on-the-fly while rendering.
Right-click on the rendered image and select "Lock bucket starting point" to lock it.
|Allows you to render regions in the V-Ray VFB.|
|Links the V-Ray VFB to Pdplayer.|
Left click enables/disables the test resolution in the VFB. Right-click to bring up menu to select the percentage of the render resolution to set as the test resolution. Note: This only affects V-Ray and does not affect the native Maya test resolution setting found under Maya's Render menu.
|Enables the Debug shading/Isolate selected option in IPR. Left-mouse click and hold the button to open a context menu with the debug shading options.|
|Renders only the selected object(s), while the rest of the scene is rendered black.|
|Locks the selection to the currently selected object. This allows making changes to the scene while shading only the locked object.|
|Renders only the light contribution in the scene.|
|Shows only the ambient occlusion in the scene.|
|Shows the rendered objects in wireframe.|
|Shows the normals of the rendered objects.|
|Displays the UV coordinates of the rendered objects in color grade.|
|Displays the Barycentric coordinates of the rendered objects.|
Starts interactive rendering. Right-click to access a list of available cameras from which to render. You can access this context menu even when the IPR is running and switch the view on the go.
|Pauses interactive rendering. When paused, IPR stops loading the CPU, but the engine will continue to run and keep track of changes to the scene. Clicking this button again resumes interactive rendering and applies any changes to the active IPR session.|
|Stops the current rendering|
Repeat the last render. Right-click to access a list of available cameras from which to render.
|Opens the Color Corrections dialog, which lets you define color corrections of various color channels. Right-click to dock or undock it.|
|Forces color clamping in the V-Ray VFB. Click and hold left mouse button to display the clamped colors in the V-Ray VFB.|
|Permanently opens the info dialog which will give you information about the pixel on which you right-click. If you right-click over a pixel without turning this setting on, you will see the info dialog only while your mouse button is pressed.|
|Enables the Hue/Saturation/Lightness color corrections.|
|Enables the color balance corrections.|
|Enables the levels color corrections.|
|Enables the curve color corrections.|
Enables the exposure corrections.
|Enables the use of a background image.|
|Displays the image in sRGB color space. Click and hold the left mouse button to switch between sRGB color space and ICC.|
|Enables and disables the effect of the Look Up table loaded in the Color Corrections settings. Hold down to choose between LUT and OCIO color corrections.|
|Shows the V-Ray VFB history window. Right-click to dock or undock it.|
|Enables visualization of the pixel aspect ratio.|
|Enables or disables stereoscopic preview. Click and hold down the left mouse button to pick between several stereoscopic modes.|
|Opens the Lens Effects controls. Right-click to dock or undock them.|
The V-Ray VFB has robust Color Corrections controls (as seen in the image in the Overview) which are enabled with the icon (all covered here.) from the lower left corner of the VFB window. Color Corrections include Exposure, Hue/Saturation, Curves, etc. and are
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 window (shown below). History files are stored as 32-bit .vrimg files in a user-specified folder. The Render history can be docked to the VFB (as shown above in the Overview), or it can float separately as shown below. In addition to keeping history, this feature can display two images in the VFB for comparison. The images are then compared using a sliding division line.
|Enables the V-Ray VFB history.|
|Saves the current image from the VFB to the render history.|
|Loads the image selected in the Render history to the VFB.|
|Removes the selected image from the render history.|
|Sets the currently selected image as image A for A/B comparison in the VFB.|
|Sets the currently selected image as image B for A/B comparison in the VFB.|
|Swaps the A and B images.|
|Enables or disables the image comparison. Click and hold the button to switch between horizontal and vertical comparison.|
|Opens out the Render History Settings window.|
The keyboard keys from 1 to 9 are used to quickly switch between the first 9 images in 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 – Add a text comment to the image; the comment appears in the "Details" column.
Set A – Set the image as the 'A' image when comparing two images.
Set B – Set the image as the 'B' image when comparing two images.
Load – Load the selected image in the VFB (same as double-clicking on the history image).
Delete – Deletes the selected image from the history.
Load V-Ray Settings – Applies the V-Ray Render settings stored in the stored image.
Compare V-Ray Settings – Opens a comparison window that displays any differences in the current render setting with the saved ones.
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. 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 Maya.
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 Color corrections saved in the stored image.
Open Scene – Loads the rendered scene in Maya. This option works as long as the initial file path of the scene has not changed after the render.
Reload History – Updates the Render History with the current .vrimgs in the VFB history folder.
Render History Settings
This window allows the user to specify VFB History settings such as to what location the history will be saved, and the amount of disk space to use.
History Directory – Specifies the location where render history images will be saved as V-Ray Image files (.vrimg).
Maximum Size on Disk (MB) – Specifies the max amount of disk space to use for the render history images. When the history exceeds the specified amount, the oldest images will be deleted.
Use Project Path – When enabled, creates a new vfb_history folder to use as the History Directory within the current Maya project directory.
Auto Save – When enabled, all rendered image will automatically be saved to the history.
Completed Renders Only – When enabled, only completed rendered images will automatically be saved to the history.
Auto Load Color Corrections – When enabled, color corrections saved in the stored image will automatically be loaded into the Color Corrections panel.
Clear – Clears all images in the render history.
Resize VFB on Load Image – When enabled, the VFB will be automatically resized to fit the loaded image.
|Toggles open Stamp Tools at the bottom of the VFB.|
|Applies a stamp with rendering metadata to the image.|
|Opens the Stamp Variables window to make it easy to copy different types of information onto the stamp.|
|Align stamp options; Click and hold to change from Left alignment to Right alignment or Center alignment.|
|Change stamp placement from align Bottom to align Top.|
|Opens the Font window to change font, its style, and size.|
Stamp variables can be typed directly into the stamp text box with a % symbol before and separated with a | symbol. Example: %rendertime | %frame | %camera
Alternatively, the Stamp variable window can be used to select/highlight variables and clip on the Copy to stamp button to add them to the stamp textbox
|vraycore||Version of the V-Ray core|
|rendertime||The render time for the last completed frame|
|vrayversion||Internal V-Ray version|
|filename||Maya project file name|
|primitives||Number of internal V-Ray primitives used in rendering|
|computername||The name of the computer this frame was rendered on|
|date||Date at the end of rendering|
|time||Time at the end of rendering|
|ram||Physical memory available (RAM)|
|vmem||Virtual memory available|
|mhz||The speed in Mhz of the CPUs|
|cpu||CPU type and number of CPUs available|
|numPasses||Sampling level reached: number of passes|
|numSubdivs||Sampling level reached: number of subdivs|
Here is the list of shortcuts to navigate through the VFB image. Please note that VFB window must have the current focus for the shortcuts to have effect:
|CTRL+Left click, CTRL+Right click||Zoom in/Zoom out|
|Mouse wheel||Zoom in/Zoom out|
|Double-click left button||Zoom to 100%|
Show the info dialog with the properties of the last pixel clicked. In order to see the info non-stop - turn on the info dialog button
When rendering with IPR, right clicking in the VFB will open an additional IPR Shortcuts menu.
|Page Up/Page Down||Switch between render elements|
|Middle button dragging||Pan (hand tool)|
|+ / -||Zoom in/Zoom out|
|*||Zoom to 100%|
|Arrow keys||Pan left, up, right, down|
|1-9||Load the respective image from the VFB history|
|Ctrl+C||Copy the VFB image to the Windows clipboard; the image is copied exactly as it appears on the screen (meaning sRGB/LUT/OCIO etc corrections are applied). The full resolution image is copied to the clipboard, even if the VFB view is zoomed in/out.|
When rendering with IPR, the following menu becomes available when right clicking in the VFB.
Select Object – When enabled, allows the user to directly select scene objects through the VFB. Multiple objects can be selected with SHIFT + left click.
Select Material – When enabled, allows materials assigned to objects to be selected by clicking their objects in the VFB. This feature is limited to one material applied per object, and does not support multiple materials applied to a single object.
Set focus point – When enabled, allows the user to set the camera focus distance by left clicking in the VFB. This requires rendering with a V-Ray Physical Camera with Depth of Field enabled or a regular camera with the Depth of Field Camera Overrides enabled.
Pixel info – Opens or closes the pixel information dialog.
VFB Progress Bar
The nested progress bar gives real-time updates about the status of the render process.
- Using a render region and saving the frame as an .exr file through the VFB (Save current channel, Save to separate files and Save to single file) saves only the render region. This is done regardless of the V-Ray output image options Data window. Disable the render region in order to save the whole frame as an .exr through the 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.