A demonstration of the new shortest path node with custom edge cost in Blender, Geometry Nodes.

The file has 3 versions of the setup with increasing complexity for easier readability. It utilizes the new "Shortest Path" node in Blender 3.4 and adds custom edge cost to create the growth effect by proximity to a custom effector object.

The most important control nodes are highlighted in red, so you can experiment with the settings values. (They are not exposed as Group Input to the Modifier controls in the Modifier side tab, for easier readability of the node tree.)

(IMPORTANT !) The setup will only work in Blender 3.4 ! Be sure to download it from the official Blender homepage.

There are 3 versions available -

1. Tree_Static

In this setup we start with an icosphere, and then use the shortest path calculation nodes. Here we dont use custom edge cost, but leave it empty - meaning it uses the default cost, the distance between vertices (and chooses the shortest value). We choose a vertex manually to be the end vertex of the calculations. Then we move the vertices toward an effector object and delete the closest ones to create an "opening".

In this node setup the proximity of the effector object does not influence the "branching", hence the name.

2. Tree_CEC_No_Proximity

Here we create an icosphere as base object, and do the same procedure, meaning delete vertices by proximity to an effector object, but here

- WE USE a custom edge cost, the distance to the effector object, so the branches are recalculated every time the object moves.

- We use the closest (or furthest) vertex as end vertex for the shortest path calculations. This way we can conveniently define in real time the branching points by moving the effector.

- We dont move the vertices toward the effector, so the sphere stays "spherical"

3. Tree_CEC_With_Proximity

The same as 2, but here we move the closest vertices toward the effector object.