object.ratio

Type Number
Object Joint
Library physics.*
Revision 2017.3179
Keywords joint, ratio
See also object.joint1
object.joint2
Physics Joints (guide)

Overview

Applies only to "pulley" and "gear" joints.

For a "pulley" joint, indicates the current joint ratio. For this joint type, this property is read-only, but the ratio value can be initially set as the final parameter in the joint constructor and adjusted to simulate a block and tackle arrangement. In such a scenario, one side of the pulley rope moves faster than the other. The default ratio is 1.0 which simulates a simple pulley.

For a "gear" joint, this property can be either set or read, and it indicates the ratio at which the motor-driven joint drives the corresponding joint in the gear configuration. This ratio can be either positive or negative, depending on the direction required to create an accurate simulation.

Examples

local pulleyJoint = physics.newJoint( "pulley", bodyA, bodyB, anchorA_x, anchorA_y, anchorB_x, anchorB_y, bodyA.x, bodyA.y, bodyB.x, bodyB.y, 1.0 )
 
print( pulleyJoint.length1 )
print( pulleyJoint.length2 )
print( pulleyJoint.ratio )
local gearJoint = physics.newJoint( "gear", bodyA, bodyB, joint1, joint2, 1.0 )
print( gearJoint.ratio )

-- Change gear joint ratio
gearJoint.ratio = 0.4