I decided to use a club to kick a ball and let it roll on the turf in RealityKit, but now I can only let it slide but can not roll.
I add collision on the turf(static), club (kinematic) and the ball(dynamic), and set some parameters: radius, mass.
Using these parameters calculate linear damping, inertia, besides, use time between frames and the club position to calculate speed. Code like these:
let radius: Float = 0.025
let mass: Float = 0.04593 // 质量,单位:kg
var inertia = 2/5 * mass * pow(radius, 2)
let currentPosition = entity.position(relativeTo: nil)
let distance = distance(currentPosition, rgfc.lastPosition)
let deltaTime = Float(context.deltaTime)
let speed = distance / deltaTime
let C_d: Float = 0.47 //阻力系数
let linearDamping = 0.5 * 1.2 * pow(speed, 2) * .pi * pow(radius, 2) * C_d //线性阻尼(1.2表示空气密度)
entity.components[PhysicsBodyComponent.self]?.massProperties.inertia = SIMD3<Float>(inertia, inertia, inertia)
entity.components[PhysicsBodyComponent.self]?.linearDamping = linearDamping
// force
let acceleration = speed / deltaTime
let forceDirection = normalize(currentPosition - rgfc.lastPosition)
let forceMultiplier: Float = 1.0
let appliedForce = forceDirection * mass * acceleration * forceMultiplier
entityCollidedWith.addForce(appliedForce, at: rgfc.hitPosition, relativeTo: nil)
Also I try to applyImpulse but not addForce, like:
let linearImpulse = forceDirection * speed * forceMultiplier * mass
No matter how I adjust the friction(static, dynamic) and restitution, using addForce or applyImpulse, the ball can only slide. How can I solve this problem?
RealityKit
RSS for tagSimulate and render 3D content for use in your augmented reality apps using RealityKit.
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I'm building a proof of concept application leveraging the PlaneDetectionProvider to generate UI and interactive elements on a horizontal plane the user is looking at. I'm able to create a cube at the centroid of the plane and change it's location via position. However, I can't seem to rotate the cube programmatically and from this forum post in September I'm not sure if the modelEntity.move functionality is still bugged or the documentation is not up to date.
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Hi everyone,
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Thanks in advance,
Nicolas