Merge pull request #15145 from WestLangley/dev-waves_example

Particles waves example: convert to THREE.Points

examples/webgl_points_waves.html

@@ -40,6 +40,36 @@
 		<script src="js/WebGL.js"></script>
 		<script src="js/libs/stats.min.js"></script>
 
+		<script type="x-shader/x-vertex" id="vertexshader">
+
+			attribute float scale;
+
+			void main() {
+
+				vec4 mvPosition = modelViewMatrix * vec4( position, 1.0 );
+
+				gl_PointSize = scale * ( 300.0 / - mvPosition.z );
+
+				gl_Position = projectionMatrix * mvPosition;
+
+			}
+
+		</script>
+
+		<script type="x-shader/x-fragment" id="fragmentshader">
+
+			uniform vec3 color;
+
+			void main() {
+
+				if ( length( gl_PointCoord - vec2( 0.5, 0.5 ) ) > 0.475 ) discard;
+
+				gl_FragColor = vec4( color, 1.0 );
+
+			}
+
+		</script>
+
 		<script>
 
 			if ( WEBGL.isWebGLAvailable() === false ) {
@@ -53,7 +83,7 @@
 			var container, stats;
 			var camera, scene, renderer;
 
-			var particles, particle, count = 0;
+			var particles, count = 0;
 
 			var mouseX = 0, mouseY = 0;
 
@@ -73,30 +103,54 @@
 
 				scene = new THREE.Scene();
 
-				particles = new Array();
-
-				var material = new THREE.SpriteMaterial( {
+				//
 
-					map: new THREE.TextureLoader().load( 'textures/sprites/circle.png' ),
+				var numParticles = AMOUNTX * AMOUNTY;
 
-				} );
+				var positions = new Float32Array( numParticles * 3 );
+				var scales = new Float32Array( numParticles );
 
-				var i = 0;
+				var i = 0, j = 0;
 
 				for ( var ix = 0; ix < AMOUNTX; ix ++ ) {
 
 					for ( var iy = 0; iy < AMOUNTY; iy ++ ) {
 
-						particle = particles[ i ++ ] = new THREE.Sprite( material );
-						particle.position.x = ix * SEPARATION - ( ( AMOUNTX * SEPARATION ) / 2 );
-						particle.position.z = iy * SEPARATION - ( ( AMOUNTY * SEPARATION ) / 2 );
-						scene.add( particle );
+						positions[ i ] = ix * SEPARATION - ( ( AMOUNTX * SEPARATION ) / 2 ); // x
+						positions[ i + 1 ] = 0; // y
+						positions[ i + 2 ] = iy * SEPARATION - ( ( AMOUNTY * SEPARATION ) / 2 ); // z
+
+						scales[ j ] = 1;
+
+						i += 3;
+						j ++;
 
 					}
 
 				}
 
-				renderer = new THREE.WebGLRenderer();
+				var geometry = new THREE.BufferGeometry();
+				geometry.addAttribute( 'position', new THREE.BufferAttribute( positions, 3 ) );
+				geometry.addAttribute( 'scale', new THREE.BufferAttribute( scales, 1 ) );
+
+				var material = new THREE.ShaderMaterial( {
+
+					uniforms: {
+						color: { value: new THREE.Color( 0xffffff ) },
+					},
+					vertexShader: document.getElementById( 'vertexshader' ).textContent,
+					fragmentShader: document.getElementById( 'fragmentshader' ).textContent
+
+				} );
+
+				//
+
+				particles = new THREE.Points( geometry, material );
+				scene.add( particles );
+
+				//
+
+				renderer = new THREE.WebGLRenderer( { antialias: true } );
 				renderer.setPixelRatio( window.devicePixelRatio );
 				renderer.setSize( window.innerWidth, window.innerHeight );
 				container.appendChild( renderer.domElement );
@@ -178,22 +232,31 @@
 				camera.position.y += ( - mouseY - camera.position.y ) * .05;
 				camera.lookAt( scene.position );
 
-				var i = 0;
+				var positions = particles.geometry.attributes.position.array;
+				var scales = particles.geometry.attributes.scale.array;
+
+				var i = 0, j = 0;
 
 				for ( var ix = 0; ix < AMOUNTX; ix ++ ) {
 
 					for ( var iy = 0; iy < AMOUNTY; iy ++ ) {
 
-						particle = particles[ i ++ ];
-						particle.position.y = ( Math.sin( ( ix + count ) * 0.3 ) * 50 ) +
-							( Math.sin( ( iy + count ) * 0.5 ) * 50 );
-						particle.scale.x = particle.scale.y = ( Math.sin( ( ix + count ) * 0.3 ) + 1 ) * 4 +
-							( Math.sin( ( iy + count ) * 0.5 ) + 1 ) * 4;
+						positions[ i + 1 ] = ( Math.sin( ( ix + count ) * 0.3 ) * 50 ) +
+										( Math.sin( ( iy + count ) * 0.5 ) * 50 );
+
+						scales[ j ] = ( Math.sin( ( ix + count ) * 0.3 ) + 1 ) * 8 +
+										( Math.sin( ( iy + count ) * 0.5 ) + 1 ) * 8;
+
+						i += 3;
+						j ++;
 
 					}
 
 				}
 
+				particles.geometry.attributes.position.needsUpdate = true;
+				particles.geometry.attributes.scale.needsUpdate = true;
+
 				renderer.render( scene, camera );
 
 				count += 0.1;