var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera(60, window.innerWidth / window.innerHeight, 1, 1000);
camera.position.set(0, 5, 10);
var renderer = new THREE.WebGLRenderer({
antialias: true
});
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
var controls = new THREE.OrbitControls(camera, renderer.domElement);
var geom = new THREE.PlaneGeometry(20, 20, 10, 10);
geom.vertices.forEach(v => {
v.z = THREE.Math.randFloat(-1, 1);
});
geom.rotateX(-Math.PI * .5);
geom.computeFaceNormals();
geom.computeVertexNormals();
var uniforms = {
center: {
value: new THREE.Vector3()
},
size: {
value: new THREE.Vector2(1, 1)
},
lineHalfWidth: {
value: 0.1
}
}
var matShader = new THREE.ShaderMaterial({
uniforms: uniforms,
vertexShader: vertShader,
fragmentShader: fragShader
});
var matWire = new THREE.MeshBasicMaterial({
color: "gray",
wireframe: true
});
var obj = THREE.SceneUtils.createMultiMaterialObject(geom, [matShader, matWire]);
scene.add(obj);
var gui = new dat.GUI();
gui.add(uniforms.size.value, "x", .5, 5.0).name("size.x");
gui.add(uniforms.size.value, "y", .5, 5.0).name("size.y");
gui.add(uniforms.lineHalfWidth, "value", .05, 2.0).name("line half-width");
var raycaster = new THREE.Raycaster();
var mouse = new THREE.Vector2();
var intersects = [];
var point = new THREE.Vector3();
window.addEventListener("mousemove", function(event) {
mouse.x = (event.clientX / window.innerWidth) * 2 - 1;
mouse.y = -(event.clientY / window.innerHeight) * 2 + 1;
raycaster.setFromCamera(mouse, camera);
intersects = raycaster.intersectObject(obj, true);
if (intersects.length === 0) return;
obj.worldToLocal(point.copy(intersects[0].point));
uniforms.center.value.copy(point);
}, false);
render();
function render() {
requestAnimationFrame(render);
renderer.render(scene, camera);
}
body {
overflow: hidden;
margin: 0;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/94/three.min.js"></script>
<script src="https://cdn.rawgit.com/mrdoob/three.js/0949e59f/examples/js/controls/OrbitControls.js"></script>
<script src="https://cdn.rawgit.com/mrdoob/three.js/0949e59f/examples/js/utils/SceneUtils.js"></script>
<script src="https://cdn.rawgit.com/mrdoob/three.js/0949e59f/examples/js/libs/dat.gui.min.js"></script>
<script>
var vertShader = `
varying vec2 vPos;
void main() {
vPos = position.xz;
gl_Position = projectionMatrix *
modelViewMatrix *
vec4(position,1.0);
}
`;
var fragShader = `
uniform vec3 center;
uniform vec2 size;
uniform float lineHalfWidth;
varying vec2 vPos;
void main() {
vec2 Ro = size * .5;
vec2 Uo = abs( vPos - center.xz ) - Ro;
vec3 c = mix(vec3(1.), vec3(1.,0.,0.), float(abs(max(Uo.x,Uo.y)) < lineHalfWidth));
gl_FragColor = vec4(c, 1. );
}
`;
</script>
THREE.DecalGeometry()
的源代码。我不能确定它是否完全符合你的需求,但可以作为一种选项。 - prisoner849minX,minY,maxX,maxY
作为统一变量,并对那些距离这些线一定范围内的像素进行着色。需要注意保持线宽在斜坡上的一致性。 - Don McCurdy