Path management basics

In lesson 12, when studying the Center Blur effect, we already discussed the idea that an effect may make use of the Position parameters which will then define a path on the screen.
We will now discuss this Path notion in more detail.

When an effect authorizes use of a path(s) for one or several of its parameters, you have access to the Tools menu in the panel of the corresponding effect as shown opposite.

This is what it contains:
* You may use the Pixel tracker to create a path.
* You may also record a stroke on the screen, to create a path.
* The third option of the Tools menu allows you to re-use a path you have already created previously in your effects stack and use it with the current parameters.
* As is the case for the palettes, the tool settings, the effects, etc, a path may be renamed, saved, etc. The option Path Manager is used for all these tasks.
* The option Add to bin allows you to save the current path under a name of your choice for later use (we have already done the same for customized palettes, mixers, tools ..... ).
* The Copy from path bin allows you to re-use a path saved in the Bin for your position parameter.
* The Center option replaces the position values for the current keyframe with those of the center of the image.
* The Constant Speed option allows you to replace all the position values of the keyframes along the path, to have always the same distance between 2 adjoining frames.
* The Reset option deletes all the keyframes of your effect.