Is there a way in three.js to turn a cube mesh shape into a diamond shape doing something like rotating the axis of the scale and then scaling it? I'm trying to create a flat-ish diamond shape, something like x50,y50,x10. If not, then what's the best way to create a diamond mesh, or a triangle mesh shape?
If you just turn the cube on its end and scale x you'll still have a (now imbalanced) rectangle shape, but if you turn it on it's end, reorient the axis of scale somehow so it's stretching across the middle from point to point, now you could just squeeze the cube with scale x, and you'd have a nice diamond shape with a thin waist.
For clarification, here's a pic of the mesh shape I am trying to make, ideally the diamond shape on the left, but the triangle shape will do also.
So, is there some way to rotate the axis of the scale? Is that what new THREE.Matrix4().makeTranslation is for? How do I use that in this context?
See plunker of my attempt here. Clearly my cube.scale.x = 0.5; code is not working and needs the axis of transform to be shifted.
Here's the js:
cube = new THREE.Mesh( geometry, material );
cube.rotation.z = Math.PI / 4 ;
cube.position.y = 35;
cube.scale.x = 0.5;
scene.add( cube );
If you want to convert your cube or box into a diamond shape, then the easiest method is to transform your geometry using a pattern like this one:
var geometry = new THREE.BoxGeometry( 100, 100, 20 );
geometry.applyMatrix( new THREE.Matrix4().makeRotationZ( Math.PI / 4 ) );
geometry.applyMatrix( new THREE.Matrix4().makeScale( 1, 2, 1 ) ); // optional
Once you create your mesh, you still have the option of further scaling the mesh, itself.
mesh = new THREE.Mesh( geometry, material );
mesh.scale.set( sz, sy, sz );
scene.add( mesh );
three.js r.71
What you need to do is to create a hierarchy of objects, the inner object will rotate around the z-axis and the outer object will scale on the x-axis.
mesh = new THREE.Mesh(geometry, material);
mesh.rotation.z = Math.PI / 4; // rotate by 45 degrees
var group = new THREE.Group();
group.add( mesh );
group.scale.x = 0.5; // scale by 0.5
scene.add( group );
Here is a fiddle: http://jsfiddle.net/3gxqboer/
Related
I am working on a project that want to move small objects and show them in a 360 image using ThreeJS library. So I am using Spherical coordinate system in a sphere with some radius to move the objects. User starts seeing the app in the center of the sphere. I want to show some grid helper lines on the sphere ( very similar to longitude and latitude lines). I found the following code from here in the library:
var radius = 10;
var radials = 16;
var circles = 8;
var divisions = 64;
var helper = new THREE.PolarGridHelper( radius, radials, circles, divisions );
scene.add( helper );
But it only adds a polar plate with some circles not a sphere shape grid helper to the scene.
PolarGridHelper is a flat circle. If you want a spherical geometry just use SphereBufferGeometry and give it a wireframe look:
var radius = 10;
var latSegments = 18; // 10° increments
var longSegments = 36; // 10° increments
var geometry = new THREE.SphereBufferGeometry( radius, longSegments, latSegments);
var material = new THREE.MeshBasicMaterial({
color: 0xffffff,
wireframe: true
});
var sphere = new THREE.Mesh( geometry, material );
scene.add( sphere );
I am using Three.js and PointerLockControls to create simple FPS game. What I am trying to do is to attach a weapon to the camera/controls.
I was able to position the gun in front of the camera and move it along on the x/y axis, but it does not move along the z axis (up/down).
function updateGun() {
if (weapon) {
const yaw = controls.getObject();
weapon.position.set(
yaw.position.x - Math.sin(yaw.rotation.y) * 3,
yaw.position.y - 1,
yaw.position.z - Math.cos(yaw.rotation.y) * 3);
weapon.rotation.set(
yaw.rotation.x,
(yaw.rotation.y - Math.PI),
yaw.rotation.z);
}
}
If you are using PointerLockControls and want to add an object that remains in front of the camera, you can use this pattern:
var mesh = new THREE.Mesh( new THREE.SphereGeometry( 5, 16, 8 ), new THREE.MeshNormalMaterial() );
mesh.position.z = - 100; // some negative number
camera.add( mesh );
If you are not using PointerLockControls, you can still use the same technique, you just have to be sure to add the camera as a child of the scene.
scene.add( camera );
camera.add( mesh );
three.js r.84
I used STLLoader to load an stl onto a threeJS scene returning a BufferGeometry.
I then used
myMesh.position.set( x,y,z )
myMesh.rotation.setFromQuaternion ( quaternion , 'XYZ');
to translate the geometry. This effectively changes the
myMesh.position
myMesh.quaternion
Translation is happening in the scene and all works well.
I expected that the
myMesh.geometry.attributes.position.array
would be different before and after the translation - but it remained identical. I want to extract the new veritces from the buffergeometry after translation.
I tried to call
myMesh.geometry.dynamic = true;
myMesh.geometry.attributes.position.needsUpdate = true;
in the render loop but no luck as I haven't updated the vertices explicity.
You want to get the world position of a mesh's geometry, taking into consideration the mesh's transform matrix, mesh.matrix. Also, your mesh geometry is THREE.BufferGeometry.
Here is the pattern to follow:
mesh = new THREE.Mesh( geometry, material );
mesh.position.set( 10, 10, 10 );
mesh.rotation.set( - Math.PI / 2, 0, 0 );
mesh.scale.set( 1, 1, 1 );
scene.add( mesh );
mesh.updateMatrix(); // make sure the mesh's matrix is updated
var vec = new THREE.Vector3();
var attribute = mesh.geometry.attributes.position; // we want the position data
var index = 1; // index is zero-based, so this the the 2nd vertex
vec.fromAttribute( attribute, index ); // extract the x,y,z coordinates
vec.applyMatrix4( mesh.matrix ); // apply the mesh's matrix transform
three.js r.71
I've already searched, but didn't find anything that helps:
I got an vector and a CylinderGeometry Mesh. I want to acchieve, that the cylinder is facing the point where the vector is showing. As input I got a position (c) and a direction (m) (like a line equation: 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
}
But it looks like the direction is the direct opposite of what I want to acchieve.
I've also tried stuff like translation:
geometry.applyMatrix( new THREE.Matrix4().makeTranslation(0, length/2, 0));
and tried to get the rotation manually like line.rotation.x = direction.angleTo(vec3(1,0,0))* 180 / Math.PI;. But none of them worked like I needed.
This works for me:
// 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 );
I currently have a cube that I'm trying to rotate on a corner. I need it to spin on the corner like the photo below.
http://www.flickr.com/photos/fiu/2198328580/
I'm new to Three.js, so I'm sorry if this is a dumb question.
Here's the code for what I currently have
var geometry= new THREE.CubeGeometry (200,200,200, 4, 4, 4);
// material
var material = new THREE.MeshLambertMaterial({
map: THREE.ImageUtils.loadTexture('inc/cube.jpg'), overdraw: true
});
cube = new THREE.Mesh( geometry, material );
cube.overdraw = true;
cube.position.y = 80;
cube.position.x = 5;
cube.position.z = 6;
cube.rotation.z = 14.9;
cube.rotation.y = 0 ;
cube.rotation.x = 0 ;
scene.add(cube);
On another note.... since I have the cube.jpg texture on the cube, if I have the values for the THREE.CubeGeometry set to (200,200,200) without the 4's, the texture warps... Anyone know how to stop the warping?
This is what I'm using to render:
renderer = new THREE.CanvasRenderer();
renderer.setClearColorHex(0xffffff, 0);
renderer.setSize( window.innerWidth, window.innerHeight ); container.appendChild( renderer.domElement );
It seems to work across most browsers, but if I use the WebGL renderer, it gives me issues with the Opacity of the Canvas.
To see the Project as it stands right now, its at http://fiudevspace.com/spincube
Conceptually all you need is to rotate the cube 45 degrees on a different axis from the 45 degrees you have already rotated - I do not use THREE as it would get between me and my solution more than it helps - remember the rule of thumb on object rotations : first translate the center of the object back to the origin (if not already there) then rotate about each axis you need, then finally translate the object back into position (reverse of previous translation) - hope this helps