Glossary

Vocabulary that is specific to Natsura, plus the botanical terms used throughout the docs. Standard 3D and engine terminology is not redefined here.

Natsura terms

Assembly. A pre-rigged hierarchy of packed instances placed onto a tree by the Assembly Decoration. Typically a leaf cluster, branch chunk, fruit set, or similar foliage unit. See Assemblies.

Assembly library. A collection of assemblies prepared by the Assembly Resource for placement by an Assembly Decoration.

Cluster. Two distinct meanings depending on context. (a) In the Cluster Decoration, a cluster is a piece of mesh geometry deformed along a branch. (b) In phyllotaxy terminology on the Grow node, a cluster is the group of new internodes produced at one growth step (see branch_count).

Decoration. The meshing layer that turns the simulated skeleton into geometry. Decorations attach to recipe nodes via decoration inputs and run as post-process steps inside Simulate. See Decorations.

Effector. A per-point direction vector that recipe nodes (typically Grow) can read and respond to. Used to shape growth in response to forces: gravity, light, wind, neighbours. See Effectors.

Generation. An integer attribute counting recursion depth from the root: 0 is the trunk, 1 is first-generation branches, 2 is twigs off those branches, and so on. Used by Mapping to drive parameters by depth.

Graft. The procedural-extension boundary between a scanned trunk and the procedural canopy grown on top. See Create Graft Mesh and Trunk Extension.

Internode. The fundamental unit of a Natsura tree. Each growth step produces one or more internodes. Each internode carries attributes (id, parent_id, generation, age, u, width, etc.) that drive Mapping and Decorations.

Mapping. The scalar-parameter framework. A map chain reads attributes and computes a per-internode value to drive a parameter. The vector equivalent is Effectors. See Mapping.

Module. A higher-level node that describes a plant organ or composes a complex behaviour out of verbs. The current set includes Grow, Switch, Repeat, Split, Prune, Wrangle. Sometimes called "recipes" or "wrappers" in casual prose. See Simulation.

Profile. An end-tube point on a scanned trunk, selected to be the attach surface for procedural extension. See Scan Profiles.

Recipe. A graph of modules wired together to describe a plant. The output of authoring; the input of Simulate. See Simulation.

Simulate. The node that executes the recipe. Traverses the graph, evaluates mappings and effectors, resolves conditions, generates internodes, applies decorations, outputs geometry. The mandatory final step in any Natsura recipe. See Simulate.

Skeleton. The line-graph output of Simulate before decoration. A skeleton is just the structural curves; adding decorations turns it into meshed geometry.

Spawn point. A position on a tree's geometry where the Assembly Decoration places an assembly. Spawn points can be at branch tips, intersections, internodes, or custom point groups.

Trait. An attribute that lives on both an asset (in an assembly library) and a tree (per spawn point). Used by the Assembly Decoration to decide which asset goes where. See Traits.

Verbs. The low-level layer of Natsura. Each verb does one focused thing. Available at the top level for advanced custom-tool authoring, debug visibility, and direct use when a module's composition isn't the right shape. See Internal Nodes.

Wrangle. A Natsura node that exposes VEX for writing custom logic. The artist-facing Wrangle is the primary surface; specific places allow VEX without a full Wrangle (custom-effector snippets, mapping snippets).

Response modes (for effectors)

Each effector on a recipe node is consumed with a chosen response mode. The response mode determines how the effector's direction vector is applied. See Effectors for the full mechanism.

Attract. Grow in the direction of the effector vector.

Repel. Grow in the opposite direction.

Flatten. Grow at a plane perpendicular to the effector.

Align (up). Twist the local up vector of the growth frame to point toward the effector.

Level (up). Twist the local up vector to be perpendicular to the effector.

Orbit. Orbit around the effector vector, producing spiral growth patterns.

Botanical terms

Phyllotaxy. The arrangement of new internodes around a parent stem. Three patterns are common: alternate-spiral (single buds offset by a fixed angle, the golden ~137.5° in many dicots), opposite-decussate (paired buds at 180° within a pair, successive pairs rotated 90°), and whorled (three or more buds at one node). On the Grow node, the count per node is set by Multiplicity (1 for alternate, 2 for opposite-paired, higher for whorls); the angular relationship is set by spiral angle and whorl angle.

Tropism. A directional response in a growing plant. Phototropism (toward light), gravitropism (against gravity), thigmotropism (away from contact). Natsura's effector framework is the substrate for tropic responses; see Effectors. Phototropism specifically is produced by plugging an environment into Simulate, not by a dedicated light effector.

Thigmomorphogenesis. The change in a plant's growth and form in response to mechanical stimulus (wind, touch, contact) producing the shorter, stockier, often asymmetric forms seen on exposed sites. A roadmap target for Natsura; today its gross effects can be approximated with effectors and mapping.

Apical dominance. The tendency of a leading (apical) shoot to suppress the growth of lateral shoots below it. Strong apical dominance gives a single straight leader (many conifers); weak apical dominance gives a spreading, much-branched crown (many broadleaves).

Bole. The main trunk of a tree, from the ground to the first major branches.

Bifurcation. A fork, one axis dividing into two of roughly equal vigour. On the Grow node, driven by the Fork helper (branch_count).

Crown (canopy). The above-ground mass of branches and foliage. The shape of the crown (its silhouette and density) is the headline outcome most shaping work targets.

Internode (botanical). The length of stem between two nodes. In Natsura the internode is also the fundamental structural unit: see the Natsura term above.

Senescence. Biological ageing, the decline phase of a tree's life, including crown retrenchment and dead-wood retention. Partially approximated today via age attributes and pruning; deeper support is on the roadmap.

Whorl. Three or more shoots emerging at a single node, arranged around the stem. Set on the Grow node via Multiplicity and whorl angle.

Related

For the introduction to all of the above as a coherent system, see the Overview.