Updated Transform so it accepts a greyscale input per parameter. For each pixel, the parameter is multiplied by 2*v-1 (v being the value of the input's pixel) which makes it possible to affect the strength of each transform using an input image. New effects such as whirl and color guided offsets are now possible.
Added Decompose node (does the opposite of combine).
Used another color for inputs/outputs that expect/generate a greyscale image.
Added a noise node (paints randomly pixels in black or white).
Modified blur so direction can be selected (horizontal, verticla, or both).
Updated code to use string formats instead of conversion + concatenation.
Now the material node is aimed at Godot's SpatialMaterial. Textures are generated and passed to the SpatialMaterial (and not generated as shaders anymore).
Rendering textures requires a Timer (to wait for the viewport to be rendered). There has to be a better solution...
Added a couple more examples.
Rodolphe Suescun