unreal.PVGrowerGravityParams

class unreal.PVGrowerGravityParams

Bases: StructBase

PVGrower Gravity Params

C++ Source:

  • Plugin: ProceduralVegetationEditor

  • Module: ProceduralVegetation

  • File: PVGrowerParams.h

Editor Properties: (see get_editor_property/set_editor_property)

  • branch_weight_break_threshold (float): [Read-Write] How much bend a branch tolerates before snapping.

    0 = any bend breaks the branch (extreme). 1 = branches tolerate 180° bends without breaking. 0.3-0.4 produces realistic snap-off behavior for over-stressed limbs.

  • cell_density (FloatRange): [Read-Write] Wood stiffness range, young (min) to mature (max).

    Values are Young’s modulus in MPa. The simulation lerps from min (flexible young wood, default 7000 MPa) to max (stiff mature wood, default 10000 MPa) over CellDevelopmentTime cycles. Real wood E-modulus values: balsa ~3000, pine ~9000, oak ~11000, ironwood ~16000.

  • cell_development_time (float): [Read-Write] Cycles until wood reaches mature stiffness.

    How many growth cycles a branch needs to age from young (CellDensity.Min) to mature (CellDensity.Max). Default 5 means a branch born this cycle is fully mature 5 cycles later. Higher values keep branches flexible longer, increasing gravity-driven bending.

  • cell_weight (float): [Read-Write] Weight per unit of wood volume.

    Higher = heavier branches that sag more under their own weight. Pair with CellDensity for realistic species — dense hardwoods are both heavier and stiffer; balsa is light and flexible.

  • foliage_weight (float): [Read-Write] Weight added per leaf instance.

    Leaves often dominate gravity stress on young branches. Higher values make leaf-heavy branches droop more (catalpa, banana plant).

  • gravitational_force (float): [Read-Write] Strength of gravity (m/s²).

    Default 9.8 matches Earth gravity. Higher values exaggerate sag; lower values produce stiffer-looking plants regardless of mass. Useful for stylized art direction.

  • hit_ground_behaviour (PVHitGroundBehaviour): [Read-Write] What happens when a drooping branch touches the ground.

    Kill = remove the branch. Deflect = redirect along the ground. Ignore = let it pass through. Use Kill for clean pruning, Deflect for creeping vines, Ignore for purely artistic ground-following.

  • input_reinforcement (float): [Read-Write] Extra stiffness applied to inherited input skeletons.

    When chaining Growers (output of one feeds another), this stiffens the input skeleton so the chained growth doesn’t deform what came before. Set near 1 to keep the input skeleton rigid; near 0 to let it deform naturally.

  • min_gravitational_dot (float): [Read-Write] Determines how much a branch needs to face upwards upon birth to be spawned.

  • trunk_reinforcement (float): [Read-Write] Extra stiffness applied to the main trunk.

    Override for the physics: higher values keep the trunk vertical regardless of mass calculations. Useful when the simulated bend is unrealistic — e.g. for stout, mature trees that physics would otherwise show as bending excessively.