我已经搜索过,但找不到任何有用的东西:
我有一个矢量和一个CylinderGeometry网格物体。我想表示,气缸正面向矢量显示的点。作为输入,我得到一个位置(c)和一个方向(m)(如线方程:y = mx + c):
function draw (m,c, _color) {
//... create the geometry and mesh
// set the position
line.position.x = c.x;
line.position.y = c.y;
line.position.z = c.z;
// i've tried something like this:
line.lookAt(c.add(m));
//.. and add to scene
}
但看起来这个方向与我想要的方向正好相反。
我也尝试过像翻译这样的东西:
geometry.applyMatrix( new THREE.Matrix4().makeTranslation(0, length/2, 0));
并尝试像line.rotation.x = direction.angleTo(vec3(1,0,0))* 180 / Math.PI;
一样手动获取轮播。但它们都没有像我需要的那样工作。
答案 0 :(得分:4)
这对我有用:
// Make the geometry (of "distance" length)
var geometry = new THREE.CylinderGeometry( 0.6, 0.6, distance, 8, 1, true );
// shift it so one end rests on the origin
geometry.applyMatrix( new THREE.Matrix4().makeTranslation( 0, distance / 2, 0 ) );
// rotate it the right way for lookAt to work
geometry.applyMatrix( new THREE.Matrix4().makeRotationX( THREE.Math.degToRad( 90 ) ) );
// Make a mesh with the geometry
var mesh = new THREE.Mesh( geometry, material );
// Position it where we want
mesh.position.copy( from.sceneObject.position );
// And make it point to where we want
mesh.lookAt( to.sceneObject.position );