Table of Contents

This page contains information about V-Ray's standalone Lens Effects Filter Generator.


Overview


The Filter Generator is a tool to create HDR filter kernels for use in the V-Ray Frame Buffer Lens Effects' Glare Image parameter.

The V-Ray Lens Effects Filter Generator is based largely on the model presented in Physically-Based Glare Effects for Digital Images. For a complete list of references, please see the References section.



 


File Options





The file menu shows options for saving and loading presets and exporting the final filter kernel.


Radial Symmetric Pattern Parameters






The Radial Symmetric Pattern parameters control the scale of the overall Lens Filter.

Shape – Adjusts the size of the pattern.


Corona Flare Lines Pattern Parameters






The Corona Flare Pattern parameters control the amount of rays emanating from the light source.

Diametric – When enabled, mirrors the pattern across the center.

Radius – Controls the size of the pattern radius.

Number Of Lines – Controls the number of lines in the pattern.


Click here to expand the Corona Flare Lines Pattern Example

This example demonstrates how different values of the Number of Lines parameter affect the lens effect. Increasing the Number of Lines value produces more rays emanating from the light source while decreasing it lowers the number of rays.

The last image also has the Diametric parameter enabled, which mirrors the rays pattern across the center (thus producing symmetrical flares).



Number Of Lines = 100, Diametric is off

Number Of Lines = 20, Diametric is off

Number Of Lines = 5, Diametric is off

Number Of Lines = 5, Diametric is on



Special Flare Lines Pattern Parameters






The Special Flare Pattern parameters control the pattern of the Special Flares Lines.

Ray Pattern Dropdown – Determines the number of Ray groups.

Radius – Scale of the Special Flares Lines Lens kernel in Percent.

Number of Lines – Determines the amount of lines used in each ray pattern.

Range – Controls the spread of the Ray Pattern.

Rotation – Rotates the entire Special Flare Lines Pattern in degrees.


Click here to expand the Special Flare Lines Pattern Example

This example shows the effect of Range and Ray Pattern parameters on the lens appearance. The Number of Lines is set to 10 for all images.



Number of Lines = 10, Range = 10, Ray Pattern = 2

Number of Lines = 10, Range = 10, Ray Pattern = 4

Number of Lines = 10, Range = 10, Ray Pattern = 6

Number of Lines = 10, Range = 10, Ray Pattern = 8

Number of Lines = 10, Range = 40, Ray Pattern = 2

Number of Lines = 10, Range = 40, Ray Pattern = 4

Number of Lines = 10, Range = 40, Ray Pattern = 6

Number of Lines = 10, Range = 40, Ray Pattern = 8

Number of Lines = 10, Range = 80, Ray Pattern = 2

Number of Lines = 10, Range = 80, Ray Pattern = 4

Number of Lines = 10, Range = 80, Ray Pattern = 6

Number of Lines = 10, Range = 80, Ray Pattern = 8



Lenticular Halo Parameters






The Lenticular Halo parameters control the bounds of the halo.

Inner Radius – Sets the inner bounds of the Lenticular Halo

Outer Radius – Sets the outer bounds of the Lenticular Halo.


Click here to expand the Lenticular Halo Example

This example shows how changing the inner and outer bounds values affects the Lenticular Halo.



Inner Radius = 20, Outer Radius = 40

Inner Radius = 20, Outer Radius = 60

Inner Radius = 20, Outer Radius = 80

Inner Radius = 20, Outer Radius = 120

Inner Radius = 40, Outer Radius = 120

Inner Radius = 80, Outer Radius = 120



Mix Parameters






The Mix parameters control how the Lens Parameters mix together into the final Filter kernel.

Pattern 1 – Sets the percentage Radial Symmetric Pattern 1 is mixed with the final Filter kernel.

Pattern 2 – Sets the percentage Radial Symmetric Pattern 2 is mixed with the final Filter kernel.

Halo – Sets the percentage the Lenticular Halo has on the final Filter kernel.

Aspect – Determines the Aspect Ratio of the final Filter kernel.

Apply Corona Flare Pattern – Enables kernel filtering with the Corona Flare Pattern.

Apply Special Flare Pattern – Enables kernel filtering with the Special Flare Pattern.


Click here to expand the Special Flare Lines Pattern Example

The following examples show how lens parameters can be mixed together to achieve a final filter kernel.



Apply Corona Flare Pattern is on, Halo = 0, Diametric is on, Number of Lines = 5

Apply Special Flare Pattern is on, Halo = 0, Number of Lines = 10, Range = 40, Ray Pattern = 6

Apply Corona Flare Pattern is on, Apply Special Flare Pattern is on, Halo = 0, Number of Lines = 10, Range = 40, Ray Pattern = 6

Apply Corona Flare Pattern is on, Apply Special Flare Pattern is on, Halo = 35, Number of Lines = 10, Range = 40, Ray Pattern = 6

Apply Corona Flare Pattern is on, Apply Special Flare Pattern is on, Halo = 70 Number of Lines = 10, Range = 40, Ray Pattern = 6



References


Here is a list of references about the V-Ray Sun and Sky implementation, as well as general information about the illumination of the Sun.

  • G. Spencer, P. Shirley, K. Zimmerman, D.P. Greenberg
 Physically-Based Glare Effects for Digital Images.;
An online version can be found at https://www.graphics.cornell.edu/pubs/1995/SSZG95.pdf.
This paper is the base for the V-Ray Lens Effects Filter Generator.