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js实现blueprint

2026-04-06 13:58:51JavaScript

使用JavaScript实现Blueprint功能

Blueprint通常指在游戏开发或3D建模中用于创建网格、辅助线或参考线的功能。以下是几种实现方式：

使用Canvas绘制网格

通过HTML5 Canvas可以轻松创建网格系统：

js实现blueprint

const canvas = document.getElementById('blueprintCanvas');
const ctx = canvas.getContext('2d');

function drawGrid(step = 20, color = '#cccccc') {
  ctx.strokeStyle = color;
  ctx.lineWidth = 0.5;

  // 垂直线
  for (let x = 0; x <= canvas.width; x += step) {
    ctx.beginPath();
    ctx.moveTo(x, 0);
    ctx.lineTo(x, canvas.height);
    ctx.stroke();
  }

  // 水平线
  for (let y = 0; y <= canvas.height; y += step) {
    ctx.beginPath();
    ctx.moveTo(0, y);
    ctx.lineTo(canvas.width, y);
    ctx.stroke();
  }
}

drawGrid();

使用SVG创建可缩放矢量网格

SVG更适合需要缩放的场景：

const svg = document.getElementById('blueprintSVG');

function createSVGGrid(size = 20, width = 500, height = 500) {
  let grid = document.createElementNS("http://www.w3.org/2000/svg", "pattern");
  grid.setAttribute("id", "grid");
  grid.setAttribute("width", size);
  grid.setAttribute("height", size);
  grid.setAttribute("patternUnits", "userSpaceOnUse");

  let path = document.createElementNS("http://www.w3.org/2000/svg", "path");
  path.setAttribute("d", `M ${size} 0 L 0 0 0 ${size}`);
  path.setAttribute("fill", "none");
  path.setAttribute("stroke", "gray");
  path.setAttribute("stroke-width", "0.5");

  grid.appendChild(path);
  svg.appendChild(grid);

  let rect = document.createElementNS("http://www.w3.org/2000/svg", "rect");
  rect.setAttribute("width", "100%");
  rect.setAttribute("height", "100%");
  rect.setAttribute("fill", "url(#grid)");

  svg.appendChild(rect);
}

createSVGGrid();

使用Three.js实现3D参考网格

对于3D场景，可以使用Three.js的网格辅助工具：

js实现blueprint

import * as THREE from 'three';

const scene = new THREE.Scene();
const gridHelper = new THREE.GridHelper(10, 10);
scene.add(gridHelper);

// 可选：添加坐标轴辅助
const axesHelper = new THREE.AxesHelper(5);
scene.add(axesHelper);

实现动态吸附功能

在绘图工具中常见的元素吸附到网格的功能：

function snapToGrid(value, gridSize) {
  return Math.round(value / gridSize) * gridSize;
}

// 使用示例
element.addEventListener('mousemove', (e) => {
  const x = snapToGrid(e.clientX, 20);
  const y = snapToGrid(e.clientY, 20);
  element.style.left = `${x}px`;
  element.style.top = `${y}px`;
});