three.js 2D Text sprite labels
Text Sprites are nice, but if you use more then thousand of it it can slow down everything because of the GPU.
There is a "better" way, create the Sprite as Canvas, here is a function that I use too for it:
function makeTextSprite( message, parameters )
{
if ( parameters === undefined ) parameters = {};
var fontface = parameters.hasOwnProperty("fontface") ? parameters["fontface"] : "Arial";
var fontsize = parameters.hasOwnProperty("fontsize") ? parameters["fontsize"] : 18;
var borderThickness = parameters.hasOwnProperty("borderThickness") ? parameters["borderThickness"] : 4;
var borderColor = parameters.hasOwnProperty("borderColor") ?parameters["borderColor"] : { r:0, g:0, b:0, a:1.0 };
var backgroundColor = parameters.hasOwnProperty("backgroundColor") ?parameters["backgroundColor"] : { r:255, g:255, b:255, a:1.0 };
var textColor = parameters.hasOwnProperty("textColor") ?parameters["textColor"] : { r:0, g:0, b:0, a:1.0 };
var canvas = document.createElement('canvas');
var context = canvas.getContext('2d');
context.font = "Bold " + fontsize + "px " + fontface;
var metrics = context.measureText( message );
var textWidth = metrics.width;
context.fillStyle = "rgba(" + backgroundColor.r + "," + backgroundColor.g + "," + backgroundColor.b + "," + backgroundColor.a + ")";
context.strokeStyle = "rgba(" + borderColor.r + "," + borderColor.g + "," + borderColor.b + "," + borderColor.a + ")";
context.lineWidth = borderThickness;
roundRect(context, borderThickness/2, borderThickness/2, (textWidth + borderThickness) * 1.1, fontsize * 1.4 + borderThickness, 8);
context.fillStyle = "rgba("+textColor.r+", "+textColor.g+", "+textColor.b+", 1.0)";
context.fillText( message, borderThickness, fontsize + borderThickness);
var texture = new THREE.Texture(canvas)
texture.needsUpdate = true;
var spriteMaterial = new THREE.SpriteMaterial( { map: texture, useScreenCoordinates: false } );
var sprite = new THREE.Sprite( spriteMaterial );
sprite.scale.set(0.5 * fontsize, 0.25 * fontsize, 0.75 * fontsize);
return sprite;
}
I've published a module on NPM that does that for you: https://github.com/gamestdio/three-text2d
It allows you to have an Object3D
with rendered text without dealing with canvas manually.
Example:
var Text2D = require('three-text2d').Text2D
var text = new Text2D("Hello world!", { align: textAlign.right, font: '30px Arial', fillStyle: '#000000', antialias: true })
scene.add(text)