Lumberyard
Legacy Reference

Pendula Row (PRow) Attachments

To create a pendula row attachment

  1. In Geppetto, in the Properties panel, choose the number next to Attachments and Add or Insert.

  2. For Name, enter a name for the attachment.

  3. For Type, choose PRow Attachment.

  4. For Joint Row Name, choose the bone icon, then open the applicable joint to place the socket on.

  5. Adjust the values of attachment parameters for the desired result, as listed in the following table.

Pendula Row Parameters

Parameter Description
Clamp Mode Used to select the movement bounding volume of the pendula row: Cone, Half Cone, Hing, or Translational Projection.
Debug Setup When enabled, displays a green bisected spherical shape that represents the bounding volume for the simulated object's pivot.
Debug Text Enable to display debugging text in the viewport.
Activate Simulation Enable to activate the physics simulation for springs and pendula.
Simulation FPS Used to specify the frame rate of the physics simulation updates. A value of 30 indicates 30 updates per second. The valid value range is 10-255 fps, with a recommended range of 30-60 fps. This value should ideally be the same as the game frame rate.
Mass Used to specify the mass of pendula bobs. If the value of the Joint Spring parameter is zero, the Mass value has no impact on the oscillation period.
Gravity Used specify the force of gravity on pendula. While the mass of a bob has no effect on the oscillation of a pendulum, the force of gravity does. The default value of 9.81 represents Earth's gravitational force.
Damping Used to specify a velocity-dependent force such as air resistance. The faster that pendula move, the more force that is encountered, decelerating the pendula at a rate proportional to the velocity. Greater damping values result in pendula coming to rest more quickly.
Joint Spring Used to simulate position dependent forces, and is a value between 0-999 applied to the spherical joint. The further the pendulum swings away from the axis of the spring target, then the harder it tries to return.
Cone Angle Used to specify the pendula starting movement angle for cone, half-cone, and hinge-planes bounding volumes. Valid range is from 0-179 degrees, where values greater than 90 degrees form an inverse cone.
Cone Rotation Used to specify the amount of rotation relative to joints along the X, Y, and Z axes for cone, half-cone, and hinge-planes.
Rod Length Used to specify the length of pendula row rods, which impacts swinging frequency. The longer the rods, the longer the pendula oscillations.
Spring Target Used to specify two planes of rotation around the x-axis of the joints.
Turbulence Used to control frequency and amplitude of noise added to PRow joints to simulate wind and similar effects on cloth.
Max Velocity Used to clamp the velocity of the PRow pendula bobs in order to control large impulse spikes from character movements.
Cycle Select to attach the last joint in the pendula row to the first joint to form a horizontal circle. Used for cloth skirts.
Stretch Used to define the horizontal distance between pendula row joints, which defines how much cloth can stretch or shrink horizontally. A value of 0.2 indicates a stretching or shrinking of 20%.
Relax Loops Used to iteratively keep pendula row joints together horizontally. Each iteration brings the joints closer together for each frame. A value between 2-4 is recommended.
Capsule Defines the length and radius values for the capsules used for the dynamic (blue) proxies connected to each joint in the entire pendula row. Used for collision detection.
Projection Type Choose Shortarc Rotation to activate collision detection.