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Anistropic Filtering

Video Lecture

Anistropic Filtering Anistropic Filtering Anistropic Filtering

Description

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

Lesson Script

./src/client/client.ts

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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 'three/examples/jsm/libs/dat.gui.module'

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.z = 1

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) => {
    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 context.getImageData(0, 0, size, size)
}

const texture1 = new THREE.CanvasTexture(document.createElement('canvas'))
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 = new THREE.CanvasTexture(document.createElement('canvas'))
texture2.mipmaps[0] = mipmap(128, '#ff0000')
texture2.mipmaps[1] = mipmap(64, '#00ff00')
texture2.mipmaps[2] = mipmap(32, '#0000ff')
texture2.mipmaps[3] = mipmap(16, '#880000')
texture2.mipmaps[4] = mipmap(8, '#008800')
texture2.mipmaps[5] = mipmap(4, '#000088')
texture2.mipmaps[6] = mipmap(2, '#008888')
texture2.mipmaps[7] = mipmap(1, '#880088')
texture2.repeat.set(5, 50)
texture2.wrapS = THREE.RepeatWrapping
texture2.wrapT = THREE.RepeatWrapping

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

texture2.minFilter = THREE.NearestFilter
texture2.magFilter = THREE.NearestFilter

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(() => (texture2.needsUpdate = true))
textureFolder.open()

function updateMinFilter() {
    texture2.minFilter = Number(texture2.minFilter)
    texture2.needsUpdate = true
}
function updateMagFilter() {
    texture2.magFilter = Number(texture2.magFilter)
    texture2.needsUpdate = true
}

const stats = 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()

Anistropic Fitering