平面几何，每段颜色不同，部分透明

Question

I am using three.js and I want to create geometry 16x16 size. I want that each segment is different color and some of them is transparent. What is the best solution for this problem? Should i render each pixel as a single plane geometry? Or there is possible way to change single segment color/transparency.

Desired result

Answer 1

I suggest you an instance of PlaneGeometry , transform it to a so called non-indexed geometry and then add an additional color buffer attribute. Full example:

 let camera, scene, renderer; init(); render(); function init() { camera = new THREE.PerspectiveCamera(70, window.innerWidth / window.innerHeight, 0.01, 10); camera.position.z = 1; scene = new THREE.Scene(); // background const canvas = document.createElement('canvas'); const ctx = canvas.getContext('2d'); canvas.width = canvas.height = 128; ctx.fillStyle = '#ddd'; ctx.fillRect(0, 0, 128, 128); ctx.fillStyle = '#555'; ctx.fillRect(0, 0, 64, 64); ctx.fillStyle = '#999'; ctx.fillRect(32, 32, 32, 32); ctx.fillStyle = '#555'; ctx.fillRect(64, 64, 64, 64); ctx.fillStyle = '#777'; ctx.fillRect(96, 96, 32, 32); mapBg = new THREE.CanvasTexture(canvas); mapBg.wrapS = mapBg.wrapT = THREE.RepeatWrapping; mapBg.repeat.set(64, 32); scene.background = mapBg; // plane mesh const geometry = new THREE.PlaneGeometry(1, 1, 10, 10).toNonIndexed(); const positionAttribute = geometry.getAttribute('position'); const colors = []; const color = new THREE.Color(); for (let i = 0; i < positionAttribute.count; i += 6) { color.setRGB(Math.random(), Math.random(), Math.random()); const alpha = Math.random(); colors.push(color.r, color.g, color.b, alpha); colors.push(color.r, color.g, color.b, alpha); colors.push(color.r, color.g, color.b, alpha); colors.push(color.r, color.g, color.b, alpha); colors.push(color.r, color.g, color.b, alpha); colors.push(color.r, color.g, color.b, alpha); } geometry.setAttribute('color', new THREE.Float32BufferAttribute(colors, 4)); const material = new THREE.MeshBasicMaterial({ vertexColors: true, transparent: true }); const mesh = new THREE.Mesh(geometry, material); scene.add(mesh); // renderer = new THREE.WebGLRenderer({antialias: true}); renderer.setPixelRatio(window.devicePixelRatio); renderer.setSize(window.innerWidth, window.innerHeight); document.body.appendChild(renderer.domElement); } function render() { renderer.render(scene, camera); }

 body { margin: 0; }

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