V-Ray Frame Buffer Overview

• Allows you to view all render elements in a single window and switch between them easily;
• Keeps the image in full 32-bit floating-point format;
• Allows you to perform simple 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 easily;
• Allows you to apply lens effects to the rendered image.
  
  

In order to use the V-Ray VFB you need to check the Use V-Ray VFB check box in the Output tab in the Renderer Options window.

VFB Toolbar

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.

	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.
	Opens a file to be viewed in the V-Ray Frame Buffer
	Clears the contents of the frame buffer. This is helpful when starting a new render, to prevent confusion with the previous image.
	This option allows you to render regions in the V-Ray VFB.
	This will force V-Ray to render the closest bucket found to the mouse pointer. Drag the mouse over the V-Ray frame buffer while rendering to specify which buckets are rendered first. You can turn this on and off on-the-fly while rendering.
	Transfers the content of the frame buffer into Pdplayer
	Enables diagonal A/B comparison when A and B images have been selected in the history
	Enables vertical A/B comparison when A and B images have been selected in the history
	This opens permanently the info dialog which will give you information about the pixel you right-click the mouse pointer on. If you right-click the mouse pointer over a pixel without turning this setting on - then you will see the info dialog only while your mouse button is down.
	This will open the "Color Corrections" dialog which will let you define color corrections of various color channels. It will also show the histogram of the currently contained image data in the buffer. Click and drag your mid-button in the histogram to interactively scale the preview.
	When this button is clicked color values that exceed the limits will be "clamped" to the maximum possible ones.
	This button enables and disables the effect of the colors level correction.
	This button enables and disables the effect of the colors curve correction.
	This button enables and disables the effect of the exposure correction.
	This button shows the image in sRGB color space.
	Enables or disables the currently loaded Look Up Table
	Enables or disables pixel aspect
	Enables the stereo display - red/cyan
	Brings out the Lens Effects options

VFB Lens Effects

The V-Ray Lens Effects allows the user to simulate bloom and glare lens effects by filtering the rendered image with a filter kernel. It uses fast multithreaded technique to compute the result.

Bloom Effects

On - turns on the bloom lens effect.

Fill edges - enabling this option will add pixel data outside the edges of the original image. This will remove the darkening around the edges.

Mode - determines if the bloom will be applied to the RGB image, stored in a separate render element, or both.

Weight - specifies the strength of the interpolation between the filtered image and the original image.

Size - specifies the size of the filter as percentage of the image's width.

Shape - specifies the fall off of the filter.

Bloom Mask

The options in this group allow the user to control where the bloom effect will be applied.

Intensity - when enabled the bloom effect will be applied only to pixels with intensity equal to or higher than the specified value.

Object ID - when enabled the bloom effect will be applied only to objects with the specified object ID

Material ID - when enabled the bloom effect will be applied only to objects that have the material with the specified object ID

Glare Effects

On - turns on the glare lens effect.

Fill edges - enabling this option will add pixel data outside the edges of the original image. This will remove the darkening around the edges.

Type - this parameter specifies how the glare is computed. The possible values are:

• From image - takes the image specified in Bitmap as filter kernel.
• From render camera - takes the necessary parameters from the camera used to perform the rendering and automatically generates the filter kernel.
• Glare type from camera parameters - takes the camera parameters specified in the VRayLensEffects render effect itself and automatically generates the filter kernel.

Mode - determines if the glare effect will be applied to the final image, stored into a separate render element, or both. Storing to a render element only works when the V-Ray VFB is enabled.

Weight - specifies the strength of the interpolation between the filtered image and the original image.

Size - specifies the size of the filter as percentage of the image's width.

Glare image - path to the filter kernel. Available if From image option is selected.

Turn on diffraction - this option will turn the diffraction on, producing colored patterns in the glare.

Use obstacle image - enable the use of the obstacle image specified in the field below.

Camera Parameters

These options are available when the glare Type is set to Glare type from camera parameters and affect the final look of the glare effect.

f-number - the f-number used to calculate the glare. Larger values produce smaller camera aperture and stronger glare effects.

Blades - this parameter controls if the camera aperture has any blades and how many they are. This effect directly controls the "rays" of the glare.

Blades rotation - this parameter controls the rotation of the of the camera aperture blades.

Glare Mask

The options in this group allow the user to control where the glare effect will be applied.

Intensity - when enabled the glare effect will be applied only to pixels with intensity equal to or higher than the specified value.

Object ID - when enabled the glare effect will be applied only to objects with the specified object ID

Material ID - when enabled the glare effect will be applied only to objects that have the material with the specified object ID

Update Control

The options in this group allow us to control how changes to the bloom and glare effects are updated.

Interactive - when enabled the Bloom and Glare effects are updated each time a setting is changed.

Update effects - manually updates the Bloom and Glare effects.

VFB Shortcuts

Here is the list of shortcuts you can use to navigate through the VFB image. Please note that the VFB window must have the current focus for the shortcuts to work:

Changing the background color

You can change the background color of the VFB by right-clicking on the background and selecting one of the options from the pop-up menu.