Skip to content

Anisotropic Filtering

Video Lecture

Anisotropic Filtering Anisotropic Filtering

Description

Anisotropic Filtering allows us to improve the quality of the MIP maps.

<>

Lesson Script

./src/client/client.ts

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
import * as THREE from 'three'
import { OrbitControls } from 'three/examples/jsm/controls/OrbitControls'
import Stats from 'three/examples/jsm/libs/stats.module'
import { GUI } from 'dat.gui'

const scene1 = new THREE.Scene()
const scene2 = new THREE.Scene()

const axesHelper1 = new THREE.AxesHelper(5)
scene1.add(axesHelper1)
const axesHelper2 = new THREE.AxesHelper(5)
scene2.add(axesHelper2)

const camera = new THREE.PerspectiveCamera(
    75,
    window.innerWidth / window.innerHeight,
    0.1,
    1000
)
camera.position.set(0, -0.35, 0.2)

const renderer = new THREE.WebGLRenderer()
renderer.setSize(window.innerWidth, window.innerHeight)
document.body.appendChild(renderer.domElement)

new OrbitControls(camera, renderer.domElement)

const planeGeometry1 = new THREE.PlaneGeometry(2, 25)
const planeGeometry2 = new THREE.PlaneGeometry(2, 25)

// const texture1 = new THREE.TextureLoader().load("img/grid.png")
// const texture2 = new THREE.TextureLoader().load("img/grid.png")

const mipmap = (size: number, color: string): HTMLCanvasElement => {
    const imageCanvas = document.createElement('canvas') as HTMLCanvasElement
    const context = imageCanvas.getContext('2d') as CanvasRenderingContext2D
    imageCanvas.width = size
    imageCanvas.height = size
    context.fillStyle = '#888888'
    context.fillRect(0, 0, size, size)
    context.fillStyle = color
    context.fillRect(0, 0, size / 2, size / 2)
    context.fillRect(size / 2, size / 2, size / 2, size / 2)
    return imageCanvas
}

const blankCanvas = document.createElement('canvas') as HTMLCanvasElement
blankCanvas.width = 128
blankCanvas.height = 128

const texture1 = new THREE.CanvasTexture(blankCanvas)
texture1.mipmaps[0] = mipmap(128, '#ff0000')
texture1.mipmaps[1] = mipmap(64, '#00ff00')
texture1.mipmaps[2] = mipmap(32, '#0000ff')
texture1.mipmaps[3] = mipmap(16, '#880000')
texture1.mipmaps[4] = mipmap(8, '#008800')
texture1.mipmaps[5] = mipmap(4, '#000088')
texture1.mipmaps[6] = mipmap(2, '#008888')
texture1.mipmaps[7] = mipmap(1, '#880088')
texture1.repeat.set(5, 50)
texture1.wrapS = THREE.RepeatWrapping
texture1.wrapT = THREE.RepeatWrapping

const texture2 = texture1.clone()
texture2.minFilter = THREE.NearestFilter
texture2.magFilter = THREE.NearestFilter

const material1 = new THREE.MeshBasicMaterial({ map: texture1 })
const material2 = new THREE.MeshBasicMaterial({ map: texture2 })

const plane1 = new THREE.Mesh(planeGeometry1, material1)
const plane2 = new THREE.Mesh(planeGeometry2, material2)

scene1.add(plane1)
scene2.add(plane2)

window.addEventListener('resize', onWindowResize, false)
function onWindowResize() {
    camera.aspect = window.innerWidth / window.innerHeight
    camera.updateProjectionMatrix()
    renderer.setSize(window.innerWidth, window.innerHeight)
    render()
}

const options = {
    minFilters: {
        NearestFilter: THREE.NearestFilter,
        NearestMipMapLinearFilter: THREE.NearestMipMapLinearFilter,
        NearestMipMapNearestFilter: THREE.NearestMipMapNearestFilter,
        'LinearFilter ': THREE.LinearFilter,
        'LinearMipMapLinearFilter (Default)': THREE.LinearMipMapLinearFilter,
        LinearMipmapNearestFilter: THREE.LinearMipmapNearestFilter,
    },
    magFilters: {
        NearestFilter: THREE.NearestFilter,
        'LinearFilter (Default)': THREE.LinearFilter,
    },
}
const gui = new GUI()
const textureFolder = gui.addFolder('THREE.Texture')
textureFolder
    .add(texture2, 'minFilter', options.minFilters)
    .onChange(() => updateMinFilter())
textureFolder
    .add(texture2, 'magFilter', options.magFilters)
    .onChange(() => updateMagFilter())
textureFolder
    .add(texture2, 'anisotropy', 1, renderer.capabilities.getMaxAnisotropy())
    .onChange(() => updateAnistropy())
textureFolder.open()

function updateAnistropy() {
    material2.map = texture2.clone()
}
function updateMinFilter() {
    texture2.minFilter = Number(
        texture2.minFilter
    ) as THREE.MinificationTextureFilter
    texture2.needsUpdate = true
}
function updateMagFilter() {
    texture2.magFilter = Number(
        texture2.magFilter
    ) as THREE.MagnificationTextureFilter
    texture2.needsUpdate = true
}

const stats = new Stats()
document.body.appendChild(stats.dom)

function animate() {
    requestAnimationFrame(animate)

    render()

    stats.update()
}

function render() {
    renderer.setScissorTest(true)

    renderer.setScissor(0, 0, window.innerWidth / 2 - 2, window.innerHeight)
    renderer.render(scene1, camera)

    renderer.setScissor(
        window.innerWidth / 2,
        0,
        window.innerWidth / 2 - 2,
        window.innerHeight
    )
    renderer.render(scene2, camera)

    renderer.setScissorTest(false)
}
animate()

Anisotropic Filtering : Wikipedia

Comments