“Nodes” are the individual branches, fronds, leaves, zones, or proxies that comprise the tree model.
Once the tree is reasonably close to what you're looking for after editing generators, individual nodes can be selected and edited explicitly. Don't like where a branch is? Select it and move it. Is a leaf sticking out too far? Select it and delete it. Need more segments on a low branch? Select it and increase the polygonal resolution only where it is needed. It is this type of editing that gives artists the extra control needed to get precision out of a procedural modeling approach. Any node edited in this manner can still be modified by its associated generator and is still eligible to have procedural components grow off of it.
A “spine” node defines the center line of a branch or frond.
A “zone” node defines a 3D region that allows growth of other objects.
Leaf nodes can be of two types: camera-facing leaf “cards” or leaf meshes (arbitrary mesh object assigned in the Mesh Asset bar).
A “proxy” node is a placeholder object primarily used in world building.
In order to edit individual nodes such as branches, twigs, and leaves, you must change from Generation Mode to Node Edit Mode. The first button in the Edit group of the Tree Window toolbar controls the changes between Generator Mode and Node Edit Mode. This button is labeled “Generators” by default. When clicked, it will indicate the change to “Nodes.”
When selected the nodes become highlighted in cyan to allow better focus on the selected node. You can select multiple nodes by holding down CTRL while picking the desired nodes. You can select multiple nodes by holding down CTRL while picking.
Use the arrow keys (up, down, left, right) to navigate the current node selection. The up and down arrows navigate to the current node selection's parent (down) or first child generator (up). Use the left and right arrows to select the previous/next generator on the same shared parent.
When a node becomes selected, the Property Editor shows the properties for that node rather than for the generator. It is easy to tell the difference – a default node shows a value of “0” for every property. This is because nodes contain only offsets of their computed values. For instance, if you make a single node's length offset a value of “10”, and the computed length for that node was “5”, the result would be a node of length “15”. If you then went back to the generator and increased the maximum length by “7”, the node from earlier would now have a length of “22” because the offset works on top of the computed value.
In a similar manner to property value offsets, nodes often have an offset curve. To edit it, click on the curve thumbnail then edit the offset curve in the 'Curve Editor'. Offset curves augment the computed profile curve for that node, so the offset curve is “added” to (or subtracted from if dipping below zero) the computed profile curve.
On top of merely offsetting computed node values, each node's 'X','Y', and 'Z' position (in local-space) can be augmented. These transforms are represented as properties in the “Common” group. Since changing position or rotation of a node only offsets it radially or lengthwise, exposing the actual X,Y, and Z values gives the artist another level of control over node placement.
Additionally, proxy nodes are likely to only be manipulated via their 'X','Y', and 'Z' values when used in world building.
It's easy to delete a node – just select and press the delete key (or press the “X” icon on the Tree Window toolbar). Deleted nodes can be retrieved with undo (CTRL + Z). All deleted nodes can be retrieved by pressing the “Reset” button in the Generation Editor (deleting the a generator link will also result in a loss of node edits).