This system allows to configure the dependencies between the parameters. This allows you to change some parameters values depending on the system state or the values of some other parameters.
For example, branches can be longer at the bottom, and shorter on the top of the tree. To do this, you can build the following node graph:
In this case, Parameter: Path position generates a value from 0 to 100%. Accordingly, the Affect node will receive for each new branch the values of their position on the trunk.
The Min and Max values allows to limit the range of the input parameter, accordingly this will determine the range of use of the curve in the Factor and/or Chaos % values, if the Curve nodes is connected there.
For example, a new branch appeared at a trunk position of 35%. Then the Factor value will be equal to 0.65. Then the Affect node multiplies this Factor value to the path length value, i.e. the length of the branch at the 35% position will be 100cm * 0.65 = 65cm.
The Math node performs arithmetic operations, and you can also pass parameter values like Affect through the Math node.
In the example below, Parameter: Path position generates values from 0 to 100% for branches. Using the Math node with the formula A - B, we calculated 100 - [0 ... 100], and got the length of the branches from 100 to 0.
If you want to change the length of the branches, then you can add another Math node to divide the input values by 2:
If you want to get a non-linear change in branch lengths, for example, as in this screenshot:
Then you can make a graph like this:
In this case, the following operations are performed:
If you set the value of the Input B = 0.5 in Math_02, then you'll get the following branches: