I take all mesh adding to a Three.group
when I rotation the Three.group it's really do it by view but inner mesh's value are incorrect (such as rotation & position etc...)
so after rotate to do raycast get incorrect result(actually befor rotate value )
see code:
init{
_group = new THREE.Group();
_scene.add(_group);
_group.add(mesh1);
_group.add(mesh2);
_group.add(mesh.....);
}
rotateClick{
_group.rotateX(90 * Math.PI / 180)
}
dbClick{
var intersections = rayCaster.intersectObjects( _group.children);
}
Related
What I'm trying to achieve is a rotation of the geometry around pivot point and make that the new definition of the geometry. I do not want te keep editing the rotationZ but I want to have the current rotationZ to be the new rotationZ 0.
This way when I create a new rotation task, it will start from the new given pivot point and the newly given rad.
What I've tried, but then the rotation point moves:
// Add cube to do calculations
var box = new THREE.Box3().setFromObject( o );
var size = box.getSize();
var offsetZ = size.z / 2;
o.geometry.translate(0, -offsetZ, 0)
// Do ratation
o.rotateZ(CalcUtils.degreeToRad(degree));
o.geometry.translate(0, offsetZ, 0)
I also tried to add a Group and rotate that group and then remove the group. But I need to keep the rotation without all the extra objects. The code I created
var box = new THREE.Box3().setFromObject( o );
var size = box.size();
var geometry = new THREE.BoxGeometry( 20, 20, 20 );
var material = new THREE.MeshBasicMaterial( { color: 0xcc0000 } );
var cube = new THREE.Mesh( geometry, material );
cube.position.x = o.position.x;
cube.position.y = 0; // Height / 2
cube.position.z = -size.z / 2;
o.position.x = 0;
o.position.y = 0;
o.position.z = size.z / 2;
cube.add(o);
scene.add(cube);
// Do ratation
cube.rotateY(CalcUtils.degreeToRad(degree));
// Remove cube, and go back to single object
var position = o.getWorldPosition();
scene.add(o)
scene.remove(cube);
console.log(o);
o.position.x = position.x;
o.position.y = position.y;
o.position.z = position.z;
So my question, how do I save the current rotation as the new 0 rotation point. Make the rotation final
EDIT
I added an image of what I want to do. The object is green. I have a 0 point of the world (black). I have a 0 point of the object (red). And I have rotation point (blue).
How can I rotate the object around the blue point?
I wouldn't recommend updating the vertices, because you'll run into trouble with the normals (unless you keep them up-to-date, too). Basically, it's a lot of hassle to perform an action for which the transformation matrices were intended.
You came pretty close by translating, rotating, and un-translating, so you were on the right track. There are some built-in methods which can help make this super easy.
// obj - your object (THREE.Object3D or derived)
// point - the point of rotation (THREE.Vector3)
// axis - the axis of rotation (normalized THREE.Vector3)
// theta - radian value of rotation
// pointIsWorld - boolean indicating the point is in world coordinates (default = false)
function rotateAboutPoint(obj, point, axis, theta, pointIsWorld){
pointIsWorld = (pointIsWorld === undefined)? false : pointIsWorld;
if(pointIsWorld){
obj.parent.localToWorld(obj.position); // compensate for world coordinate
}
obj.position.sub(point); // remove the offset
obj.position.applyAxisAngle(axis, theta); // rotate the POSITION
obj.position.add(point); // re-add the offset
if(pointIsWorld){
obj.parent.worldToLocal(obj.position); // undo world coordinates compensation
}
obj.rotateOnAxis(axis, theta); // rotate the OBJECT
}
After this method completes, the rotation/position IS persisted. The next time you call the method, it will transform the object from its current state to wherever your inputs define next.
Also note the compensation for using world coordinates. This allows you to use a point in either world coordinates or local space by converting the object's position vector into the correct coordinate system. It's probably best to use it this way any time your point and object are in different coordinate systems, though your observations may differ.
As a simple solution for anyone trying to quickly change the pivot point of an object, I would recommend creating a group and adding the mesh to the group, and rotating around that.
Full example
const geometry = new THREE.BoxGeometry();
const material = new THREE.MeshBasicMaterial({ color: 0xff0000 });
const cube = new THREE.Mesh(geometry, material);
scene.add(cube)
Right now, this will just rotate around its center
cube.rotation.z = Math.PI / 4
Create a new group and add the cube
const group = new THREE.Group();
group.add(cube)
scene.add(group)
At this point we are back where we started. Now move the mesh:
cube.position.set(0.5,0.5,0)
Then move the group
group.position.set(-0.5, -0.5, 0)
Now use your group to rotate the object:
group.rotation.z = Math.PI / 4
I'm trying to create a camera that follows an object that rotates on a orbit around a sphere. But everytime the camera reaches the polar coordinates of the orbit, the direction changes. I just set the position of the camera according to the object that is has to follow and calling lookAt afterwards:
function render() {
rotation += 0.002;
// set the marker position
pt = path.getPoint( t );
// set the marker position
marker.position.set( pt.x, pt.y, pt.z );
marker.lookAt( new THREE.Vector3(0,0,0) );
// rotate the mesh that illustrates the orbit
mesh.rotation.y = rotation
// set the camera position
var cameraPt = cameraPath.getPoint( t );
camera.position.set( cameraPt.x, cameraPt.y, cameraPt.z );
camera.lookAt( marker.position );
t = (t >= 1) ? 0 : t += 0.002;
renderer.render( scene, camera );
}
Here's a complete fiddle: http://jsfiddle.net/krw8nwLn/69/
I've created another fiddle with a second cube which represents the desired camera behaviour: http://jsfiddle.net/krw8nwLn/70/
What happens is that the camera's lookAt function will always try to align the camera with the horizontal plane (so that the "up" direction is always (0, 1, 0). And when you reach the top and bottom of the ellipse path, the camera will instantaneously rotate 180° so that up is still up. You can also see this in your "desired behaviour" example, as the camera cube rotates so that the colors on the other side are shown.
A solution is to not use lookAt for this case, because it does not support cameras doing flips like this. Instead set the camera's rotation vector directly. (Which requires some math, but you look like a math guy.)
I'm working with three.js, attempting to model a real world camera. As such, I'd like to limit its axis of rotation to 90 degrees along x and y axises.
Is there a simply way to do this? My current code isn't working particularly well (and goes crazy when you attempt to move the camera past the X and Y boundaries simultaneously)
if(xRot != null && xRot != undefined){
camera.rotateX(xRot);
}
if(yRot != null && yRot != undefined){
camera.rotateY(yRot);
}
if(camera.rotation.x < minCameraRotX){
camera.rotation.x = minCameraRotX;
}else if (camera.rotation.x > maxCameraRotX){
camera.rotation.x = maxCameraRotX;
}
if(camera.rotation.y < minCameraRotY){
camera.rotation.y = minCameraRotY;
}else if(camera.rotation.y > maxCameraRotY){
camera.rotation.y = maxCameraRotY;
}
Any advice would be greatly appreciated!!!
I actually managed to find a solution by checking some of the existing code in a Three.js demo for a library called PointerLock. The idea is to actually stack multiple objects inside each other: start with an object that moves horizontally (the yaw object), place another object inside the yaw object that moves vertically (the pitch object), and then place the actual camera inside the pitch object.
Then, you only rotate the outside objects (yaw and pitch) along their respective axises, so if you rotate both, they'll self-correct. For example, if you rotate the yaw 45 degrees along the y-axis (making it turn to the right) and then rotate the pitch 45 degrees (making it turn downward), the pitch will go 45 degrees downward from the yaw's already rotated position.
Given that the camera is inside both, it just points wherever the yaw and pitch direct it.
Here is the code
/*
* CAMERA SETUP
*
* Root object is a Yaw object (which controls horizontal movements)
* Yaw object contains a Pitch object (which controls vertical movement)
* Pitch object contains camera (which allows scene to be viewed)
*
* Entire setup works like an airplane with a
* camera embedded in the propellor...
*
*/
// Yaw Object
var yawObject = new THREE.Object3D();
// Pitch Object
var pitchObject = new THREE.Object3D();
// Camera Object
var camera = new THREE.PerspectiveCamera(fov, aspect, near, far);
// Max Camera angles (in radians)
var minCameraRotX = 0.5;
var maxCameraRotX = 0.5;
var minCameraRotY = 1;
var maxCameraRotY = 1;
// Setup
yawObject.add( pitchObject );
pitchObject.add( camera );
scene.add(yawObject);
...
var rotateCamera = function(xRot, yRot, zRot){
yawObject.rotation.y += yRot;
pitchObject.rotation.x += xRot;
// Enforce X-axis boundaries (rotates around y-axis)
yawObject.rotation.y = Math.max( minCameraRotY, Math.min( maxCameraRotY, yawObject.rotation.y ) );
// Enforce Y-axis boundaries (rotates around x-axis)
pitchObject.rotation.x = Math.max( minCameraRotX, Math.min( maxCameraRotX, pitchObject.rotation.x ) );
}
Here is the source code I referenced: https://github.com/mrdoob/three.js/blob/acda8a7c8f90ce9b71088e903d8dd029e229678e/examples/js/controls/PointerLockControls.js
Also, this is sort of cheesy, but this little plane cartoon helped me visual exactly what was going on in my setup
I have this code, designed to find the mesh the user is clicking on:
// scene and camera are defined outside of this code
var mousePoint = new THREE.Vector2();
var raycaster = new THREE.Raycaster();
var intersections;
function onClick(event) {
mousePoint.x = event.clientX;
mousePoint.y = event.clientY;
raycaster.setFromCamera(mousePoint, camera);
intersections = raycaster.intersectObjects(
scene.children);
}
Yet every time I click, intersections comes back as an empty array, with nothing getting intersected. What am I doing wrong?
From the three.js documentation for Raycaster (emphasis mine):
.setFromCamera ( coords, camera )
coords — 2D coordinates of the mouse, in normalized device coordinates (NDC)---X and Y components should be between -1 and 1.
camera — camera from which the ray should originate
Updates the ray with a new origin and direction.
Therefore, when setting the coordinates of mousePoint, instead of setting x and y directly to event.clientX and event.clientY, they should be converted to this coordinate space:
// calculate mouse position in normalized device coordinates
// (-1 to +1) for both components
mousePoint.x = (event.clientX / window.innerWidth) * 2 - 1;
mousePoint.y = (event.clientY / window.innerHeight) * -2 + 1;
I'm new to threejs
I need to draw a sphere connected with triangles. I use Icosahedron to construct the sphere in the following way
var material = new THREE.MeshPhongMaterial({
emissive : 0xffffff,
transparent: true,
opacity : 0.5,
wireframe : true
});
var icogeo = new THREE.IcosahedronGeometry(80,2);
var mesh = new THREE.Mesh(icogeo, material);
scean.add(mesh);
But i need the width of the line to be more but line width won't show up in windows so i taught of looping through the vertices and draw a cylinder/tube between the vertices. (I can't draw lines because the LineBasicMaterial was not responding to Light.)
for(i=0;i<icogeo.faces.length;i++){
var face = icogeo.faces[i];
//get vertices from face and draw cylinder/tube between the three vertices
}
Can some one please help on drawing the tube/cylinder between two vector3 vertices?
**the problem i'm facing with wireframe was it was not smooth and i can't increase width of it in windows.
If you really want to create a cylinder between two points one way to do is to create it in a unit space and then transform it to your line. But that is very mathy.
An intuitive way to create it is to think about how would you do it in a unit space? A circle around the z axis (in x,y) and another one a bit down z.
Creating a circle in 2d is easy: for ( angle(0,360,360/numsteps) ) (x,y)=(sin(angle),cos(angle))*radius. (see for example Calculating the position of points in a circle).
Now the two butt ends of your cylinder are not in x,y! But If you have two vectors dx,dy you can just multiply your x,y with them and get a 3d position!
So how to get dx, dy? One way is http://en.wikipedia.org/wiki/Gram%E2%80%93Schmidt_process
which reads way more scary than it is. You start with your forward direction, which is your line. forward = normalize(end-start). Then you just pick a direction "up". Usually (0,1,0). Unless forward is already close to up, then pick another one like (1,0,0). Take their cross product. This gives you "left". Then take the cross product between "left" and "forward" to get "right". Now "left" and "right" are you dx and dy!
That way you can make two circles at the two ends of your line. Add triangles in between and you have a cylinder!
Even though I do believe it is an overkill for what you are trying to achieve, here is code that draws a capsule (cylinder with spheres at the end) between two endpoints.
/**
* Returns a THREE.Object3D cylinder and spheres going from top to bottom positions
* #param radius - the radius of the capsule's cylinder
* #param top, bottom - THREE.Vector3, top and bottom positions of cone
* #param radiusSegments - tessellation around equator
* #param openTop, openBottom - whether the end is given a sphere; true means they are not
* #param material - THREE.Material
*/
function createCapsule (radius, top, bottom, radiusSegments, openTop, openBottom, material)
{
radiusSegments = (radiusSegments === undefined) ? 32 : radiusSegments;
openTop = (openTop === undefined) ? false : openTop;
openBottom = (openBottom === undefined) ? false : openBottom;
var capsule = new THREE.Object3D();
var cylinderAxis = new THREE.Vector3();
cylinderAxis.subVectors (top, bottom); // get cylinder height
var cylinderGeom = new THREE.CylinderGeometry (radius, radius, cylinderAxis.length(), radiusSegments, 1, true); // open-ended
var cylinderMesh = new THREE.Mesh (cylinderGeom, material);
// get cylinder center for translation
var center = new THREE.Vector3();
center.addVectors (top, bottom);
center.divideScalar (2.0);
// pass in the cylinder itself, its desired axis, and the place to move the center.
makeLengthAngleAxisTransform (cylinderMesh, cylinderAxis, center);
capsule.add (cylinderMesh);
if (! openTop || ! openBottom)
{
// instance geometry
var hemisphGeom = new THREE.SphereGeometry (radius, radiusSegments, radiusSegments/2, 0, 2*Math.PI, 0, Math.PI/2);
// make a cap instance of hemisphGeom around 'center', looking into some 'direction'
var makeHemiCapMesh = function (direction, center)
{
var cap = new THREE.Mesh (hemisphGeom, material);
makeLengthAngleAxisTransform (cap, direction, center);
return cap;
};
// ================================================================================
if (! openTop)
capsule.add (makeHemiCapMesh (cylinderAxis, top));
// reverse the axis so that the hemiCaps would look the other way
cylinderAxis.negate();
if (! openBottom)
capsule.add (makeHemiCapMesh (cylinderAxis, bottom));
}
return capsule;
}
// Transform object to align with given axis and then move to center
function makeLengthAngleAxisTransform (obj, align_axis, center)
{
obj.matrixAutoUpdate = false;
// From left to right using frames: translate, then rotate; TR.
// So translate is first.
obj.matrix.makeTranslation (center.x, center.y, center.z);
// take cross product of axis and up vector to get axis of rotation
var yAxis = new THREE.Vector3 (0, 1, 0);
// Needed later for dot product, just do it now;
var axis = new THREE.Vector3();
axis.copy (align_axis);
axis.normalize();
var rotationAxis = new THREE.Vector3();
rotationAxis.crossVectors (axis, yAxis);
if (rotationAxis.length() < 0.000001)
{
// Special case: if rotationAxis is just about zero, set to X axis,
// so that the angle can be given as 0 or PI. This works ONLY
// because we know one of the two axes is +Y.
rotationAxis.set (1, 0, 0);
}
rotationAxis.normalize();
// take dot product of axis and up vector to get cosine of angle of rotation
var theta = -Math.acos (axis.dot (yAxis));
// obj.matrix.makeRotationAxis (rotationAxis, theta);
var rotMatrix = new THREE.Matrix4();
rotMatrix.makeRotationAxis (rotationAxis, theta);
obj.matrix.multiply (rotMatrix);
}