Settings and Macros/3D Keyer Description

From VFXPedia

Jump to: navigation, search
3D Keyer Description

[ Main Manual Page ]



3D_Keyer_v02 Download

An implementation of a 3D RGB/HSV keyer that treats pixels as points in a three-dimensional space. The alpha channel is created by looking at each pixel's distance from the reference color.

Download 3D_Keyer_v02

Development History and Discussion on PigsFly

File:ThreeDKeyer1.jpg

Based on the formula found here, this keyer is excellent for capturing semi-transparent areas or fine hair detail. Works with any color, but the included despilling controls are suitable for green and blue screens only. Credits for example images on this page: Hollywood Camera Work.



Main Inputs

The following inputs appear on the tool's tile in the Flow Editor:

Input Image:Node_Input_Gold.gif
Source image. Required.
Garbage Image:Node_Input_White.gif
A mask to be used as a garbage or holdout matte. Optional.





Controls Tab


Color

Reference color. Pick this from your blue or green screen.

Distance Math

MultiButton. Choose from two formulas. The Manhattan Distance is the sum of the distance in each color channel and creates a matte that easily contains solid areas. The Euclidean Distance uses the Pythagorean Theorem ( distance = sqrt( (r1-r2)^2 + (g1-g2)^2 + (b1-b2)^2 ) ) and creates a very soft matte that needs to be processed or combined with other keyers.

Color Space

MultiButton. The keyer's power lies in its capability to pull the matte in a variety of color spaces. By default, HSV results in great results, but you can also pull the matte in RGB, YUV (if you want the keyer to look at luma and chroma), YIQ, CMY, HLS and XYZ. The first three are probably the useful ones but you never know...

Discard Components

Checkbox. Check the channels you want the keyer to ignore. For example, if you've selected the HSV color space and you want the keyer to look at hue and saturation only, discard the 3rd component (V). If you just want to use the blue channel, select RGB and discard the 1st and 2nd component.

The remaining controls on the Spill and Matte tabs are simply copied from a Matte Control.





Further Examples

Image:ThreeDKeyer2.jpg





--Tilt