Simulate

The Simulate node is the engine of Natsura. It takes the abstract graph recipe and executes it to generate geometry.

• Execution: Traverses the graph, running the logic defined by Grow, Split, Repeat, etc.
• Resolution: Evaluates all mappings, effectors, and conditions.
• Generation: Produces the final skeleton and decoration geometry.

Concept

Build vs. Run In Natsura, you first build a graph (using Grow, Split, etc.) and then run it with Simulate. The graph defines the "DNA" of the plant; Simulate grows the plant.

Solver Loop Simulate runs a feedback loop. In each step:

1. Active tips grow (Grow nodes).
2. Conditions are checked (Switch, Prune).
3. Attributes are updated (Wrangle, Repeat).
4. New tips are spawned (Split, Fork).

Inputs

• Input 0 — Graph The Apex graph to simulate.
• Input 1 — Parms (Optional) Global parameter dictionary.
• Input 2 — Points (Optional) Source points for "Grow from Points" mode.

Parameters

Simulation

• Max Steps: Safety limit for the simulation loop.
• Seed: Global random seed.

Output

• Output Skeleton: Generates the line graph.
• Output Decorations: Generates instanced geometry (leaves, etc.).

Attributes

Simulate outputs standard attributes on the generated geometry:

• id, parent_id, generation
• u, age, width, radius
• orient, scale, variant (on decorations)

Workflow

1. Construct your graph using Grow and other nodes.
2. Connect the end of the graph to Simulate.
3. (Optional) Connect scatter points to Input 2 to grow many instances.
4. Visualize the output.

Related Nodes