Resonance effect

Basic operation

This effect is created by recursively iterating a transformation. This basic transformation is in fact two elementary operations used simultaneaously: a geometrical transformation (stretching) and a color transformation (alpha blending).

The intensity parameter defines the reduce factor applied (in range 0 to 1). This factor is used for computation of new height and width.

The Alpha parameter defines the transparency factor used to perform alpha blending between the current rendered layer and the previous one.

The Cx and Cy parameters define the starting point of this transformation

Iterative process

Each time a new layer is rendered it becomes the old one and the new width, height and application point are computed for the next layer. This process is iterated as long as the layer dimensions are greater or equal to a minimum value (for this code, this minimum is fixed to four pixels, but can be easily modified).

This iterative process is illustrated below:

Such a kind of iterative (or recursive) process can be used with many other transformations to create a lot of special effects, this resonance effect is simply one of them.

As the used techniques are explained in other pages (take a look at stretching and alpha blending effects), I will discuss no more about them in this short description.