구면 좌표계

 

출처: 위키백과

 

• θ - theta : 세로 각도 (수직 각도, 수평선에서 위로 몇 도)
• ϕ - phi : 가로 각도 (수평 각도, 원점 기준 좌우)

 

• x = r⋅sin(θ)⋅cos(ϕ)
• y = r⋅sin(θ)⋅sin(ϕ)
• z = r⋅cos(θ)

 

function degreeToRadian(degree) {

    return degree * (Math.PI / 180)

}

function radianToDegree(radian) {

    return radian * (180 / Math.PI)

}

function getRadius(x, y, z) {

    return Math.sqrt(x ** 2 + y ** 2 + z ** 2)

}

function getTheta(x, y, z) {

    const radius = getRadius(x, y, z);

    return Math.acos(z / radius)

}

function getPhi(x, y) {

    return Math.atan2(y, x)

}

function getCoordinates(r, theta, phi) {

    const x = r * Math.sin(theta) * Math.cos(phi)

    const y = r * Math.sin(theta) * Math.sin(phi)

    const z = r * Math.cos(theta)

    return { x: x, y: y, z: z }

}

 

// *** Example.

const currentValue = {

    x: -4.33,

    y: 0,

    z: -2.5,

    theta: null,

    phi: null,

    radius: null

}

currentValue.radius = getRadius(currentValue.x, currentValue.y, currentValue.z)

currentValue.theta = radianToDegree(getTheta(currentValue.x, currentValue.y, currentValue.z))

currentValue.phi = radianToDegree(getPhi(currentValue.x, currentValue.y))

console.log('currentValue: ', currentValue)

const targetValue = {

    x: null,

    y: null,

    z: null,

    theta: 120,

    phi: 240,

    radius: currentValue.radius

}

const rTheta = degreeToRadian(targetValue.theta)

const rPhi = degreeToRadian(targetValue.phi)

const coordinates = getCoordinates(targetValue.radius, rTheta, rPhi)

targetValue.x = coordinates.x

targetValue.y = coordinates.y

targetValue.z = coordinates.z

console.log('targetValue: ', targetValue)