EasyPeg Documentation

Effects: Stochastic Illumination

Stochastic Illumination is a monte carlo method for lighting. Pixels can become sources of light or darkness and shot rays of either light or darkness. The direction of each ray is chosen randomly and each pixel that is hit will absorb the energy of the ray. If a pixel is hit or if the ray passes is determined randomly and the probability can be set with the parameter Hit Prob.
Attention: This effect may take very long to compute if the number of rays is large, the offset is large and hit prob is low.

Light Source

ON

use Light Source. If you don't want to have sources of light, disable it. Either Light Source or Darkness Source must be enabled. Both can be enabled.

Source = pixels close to

The pixel with the checked characteristic is taken as reference to determine what pixels are sources. All pixels with a brightness close to the brightness of this reference pixel are selected as sources. Offset (%) specifies how close they have to be. More than one characteristic can be checked and therefor more than one pixel can be a reference pixel with the effect that much more pixels will be sources.

Minimum: Pixels with a brightness close to the minimum are sources
Median: Pixels with a brightness close to the median (if pixels are ranked by brightness, the one in the middle is taken) are sources
Maximum: Pixels with a brightness close to the maximum are sources

Offset (%)

If the brightness of a pixel is less the offset in percent away from the reference pixel, it is selected as source.

Rays

the number of rays each source shots.

Hit Prob.

means Hit Probability. It is the probability that the ray hits a pixel it passes and gets absorbed. If this probability is high, then only pixels close to the source will be influenced as the ray won't get far.

Darkness Source

like Light Source, but rays send out darkness (negative energy)

Target options

Intensity Factor of effect

the higher the more influence is given to the effect

Tips:

Make bright things shine: Then use only Light Sources and select pixels close to maximum. Increase offset or intensity to increase the effect. Decrease offset if pixels too far from the maximum are sources. Increase number of rays for a smoother effect.
Use both Light and Darkness Sources: My favourite way to do this is to select pixels close to minimum as light source and pixels close to maximum as darkness source. This will darken bright spots and brighten dark ones. Especially the dark spots will develop some interesting glowing colors. I recommend smaller Hit Probs like 20 %..

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