Develop Reference

What is required to convert threejs perspective camera to orthographic

I have some code that converts a perspective camera to an orthographic camera. The problem is that when I make the conversion, the model becomes very tiny and hard to see.
I have calculated the zoom factor for the orthographic camera, based on the distance and the FOV. Are there any other properties that I need to set on the orthographic camera (e.g. clipping plane, etc..)?
I believe the position remains the same. I'm not sure what else I need to calculate.
fieldOfView = viewInfo.fov;
var getCameraPosition = function() {
return viewer._viewport._implementation.getCamera()._nativeCamera.position;
};
// Calculate the delta position between the camera and the object
var getPositionDelta = function(position1, position2) {
return {
x: position1.x - position2.x,
y: position1.y - position2.y,
z: position1.z - position2.z
}
};
var getDistance = function(positionDelta, cameraDirection) {
return dot(positionDelta, cameraDirection);
};
distance = getDistance(positionDelta, cameraDirection),
var depth = distance;
var viewportWidth = view.getDomRef().getBoundingClientRect().width;
var viewportHeight = view.getDomRef().getBoundingClientRect().height;
var aspect = viewportWidth / viewportHeight;
var height_ortho = depth * 2 * Math.atan( fieldOfView * (Math.PI/180) / 2 )
var width_ortho = height_ortho * aspect;
var near = viewInfo.near, far = viewInfo.far;
var newCamera = new THREE.OrthographicCamera(
width_ortho / -2, width_ortho / 2,
height_ortho / 2, height_ortho / -2,
near, far );
newCamera.position.copy( viewInfo.position );
var sCamera = new vk.threejs.OrthographicCamera(); //framework creatio of threejs cam
sCamera.setZoomFactor(orthoZoomFactor);
sCamera.setCameraRef(newCamera);
view.getViewport().setCamera(sCamera);
I also tried setting the same camera properties (e.g. clipping planes etc) of the perspective for the orthographic and I still had the same problem.
I guess I am missing some property or calculation required to put the object in the same position as when it was in perspective camera view.

Let's assume you have a perspective view with a given vertical field of view angle fov_y (in degrees) and you know the size of the viewport width and height. Furthermore, you have the near and far plane. These are the values which you use to setup the THREE.PerspectiveCamera:
perspCamera = new THREE.PerspectiveCamera( fov_y, width / height, near, far );
Also, you know the position of the object and the position of the camera. An object doesn't have only a single position, but you have to choose a representative position for its depth.
First you have to calculate the depth of the object.
var v3_object = .... // THREE.Vector3 : positon of the object
var v3_camera = perspCamera.position;
var line_of_sight = new THREE.Vector3();
perspCamera.getWorldDirection( line_of_sight );
var v3_distance = v3_object.clone().sub( v3_camera );
depth = v3_distance.dot( line_of_sight );
Then you have to calculate the "size" of the rectangle which is projected to the viewport at the depth:
aspect = width / height;
height_ortho = depth * 2 * Math.atan( fov_y*(Math.PI/180) / 2 )
width_ortho = height_ortho * aspect;
With these values the THREE.OrthographicCamera can be setup like this:
var orthoCamera = new THREE.OrthographicCamera(
width_ortho / -2, width_ortho / 2,
height_ortho / 2, height_ortho / -2,
near, far );
orthoCamera.position.copy( perspCamera.position );
The positon and direction of the perspective camera can be committed to the orthographic camera like this:
orthoCamera.position.copy( perspCamera.position );
orthoCamera.quaternion.copy( perspCamera.quaternion );
See also stackoverflow question Three.js - Find the current LookAt of a camera?

convert mouse click to 3d space with orthographic camera

Three.js : rev 73
I'm using the following construct to find intersection of mouse click with objects in the 3d world (orthographic setup):
function onDocumentMouseDown(event) {
event.preventDefault();
console.log("Click");
var mouse = new THREE.Vector2();
mouse.x = (event.clientX / window.innerWidth) * 2 - 1;
mouse.y = -(event.clientY / window.innerHeight) * 2 + 1;
var raycaster = new THREE.Raycaster();
// update the picking ray with the camera and mouse position
raycaster.setFromCamera(mouse, camera);
// calculate objects intersecting the picking ray
var intersects = raycaster.intersectObjects(scene.children);
console.log("intersects: " + intersects.length);
for (var i = 0; i < intersects.length; i++) {
console.log(intersects[i].point);
}
}
However, the intersection is very inaccurate. Intersection is captured when I click near the top left of the box only.
jsFiddle: Can someone please help me understand why is this misbehaving ?
Also, if no object is being selected, I want to find out where is the click in 3d world relative to the box - left, right, below the box ? Can I use the ray itself to compute this ?

you have to get accurate mouse position for ray-casting :-
mouse.x = ( (event.clientX -renderer.domElement.offsetLeft) / renderer.domElement.width ) * 2 - 1;
mouse.y = -( (event.clientY - renderer.domElement.offsetTop) / renderer.domElement.height ) * 2 + 1;
you have to fire event listener when window resize
i update the fiddle again check it now .
add new function for window resize...
code is self explaintory ...hope you got it .
Check Update Fiddle now
updated fiddle :-
http://jsfiddle.net/gc1v0rza/5/

Three.js - Getting the X, Y, and Z coordinates of mouse click

I'm using version 68 of three.js.
I would like to click somewhere and get the X, Y, and Z coordinates. I followed the steps here, but they give me a Z value of 0: Mouse / Canvas X, Y to Three.js World X, Y, Z
Basically, if I have a mesh in the scene, and I click in the middle of it, I'm hoping to be able to calculate the same values as the position of that mesh. This is just an example. I know I could use raycasting and see if I collided with a mesh and then just check its position. However, I want this to work even if I didn't click a mesh.
Is this possible? Here is a jsfiddle: http://jsfiddle.net/j9ydgyL3/
In that jsfiddle, if I could manage to click in the center of that square, I'm hoping to calculate 10, 10, 10 for the X, Y, and Z values respectively because those are the coordinates of the square's position. Here are the two functions of concern:
function getMousePosition(clientX, clientY) {
var mouse2D = new THREE.Vector3();
var mouse3D = new THREE.Vector3();
mouse2D.x = (clientX / window.innerWidth) * 2 - 1;
mouse2D.y = -(clientY / window.innerHeight) * 2 + 1;
mouse2D.z = 0.5;
mouse3D = projector.unprojectVector(mouse2D.clone(), camera);
return mouse3D;
//var vector = new THREE.Vector3(
//( clientX / window.innerWidth ) * 2 - 1,
//- ( clientY / window.innerHeight ) * 2 + 1,
//0.5 );
//projector.unprojectVector( vector, camera );
//var dir = vector.sub( camera.position ).normalize();
//var distance = - camera.position.z / dir.z;
//var pos = camera.position.clone().add( dir.multiplyScalar( distance ) );
//return pos;
}
function onDocumentMouseUp(event) {
event.preventDefault();
var mouse3D = getMousePosition(event.clientX, event.clientY);
console.log(mouse3D.x + ' ' + mouse3D.y + ' ' + mouse3D.z);
}
I left some of the other code I tried commented out. Please note that this commented-out code didn't work in the jsfiddle website, maybe because they're still using version 54 of three.js. It works fine on my machine with version 68.
Edit: To clarify, I would like to be able to get the coordinates no matter where the mouse is. I just used a mesh in this example because it's easy to verify if it works by seeing if the calculated coordinates are the same as the mesh's. What I would really like is for it to work without using raycasting on a mesh. For example, we could have it always printing the calculated coordinates to the console every time the mouse moves, no matter what is in the scene.

You should use a THREE.Raycaster for this. When you set a list of intersectObjects you will be able to get an array of objects that intersected with the ray. So you can get the position from the 'clicked' object from returned list. Check the updated fiddle here.
I also changed your Three.js to version R68
For more advanced use of THREE.RayCaster check the examples at Threejs.org/examples like this example with interactive cubes.
Relevant code from the updated fiddle:
function getMousePosition(clientX, clientY) {
var mouse2D = new THREE.Vector3();
var mouse3D = new THREE.Vector3();
mouse2D.x = (clientX / window.innerWidth) * 2 - 1;
mouse2D.y = -(clientY / window.innerHeight) * 2 + 1;
mouse2D.z = 0.5;
mouse3D = projector.unprojectVector(mouse2D.clone(), camera);
return mouse3D;
var vector = new THREE.Vector3(
(clientX / window.innerWidth) * 2 - 1, -(clientY / window.innerHeight) * 2 + 1,
0.5);
projector.unprojectVector(vector, camera);
var dir = vector.sub(camera.position).normalize();
var distance = -camera.position.z / dir.z;
var pos = camera.position.clone().add(dir.multiplyScalar(distance));
return pos;
}
function onDocumentMouseUp(event) {
event.preventDefault();
var mouse3D = getMousePosition(event.clientX, event.clientY);
console.log(mouse3D.x + ' ' + mouse3D.y + ' ' + mouse3D.z);
var vector = new THREE.Vector3( mouse3D.x, mouse3D.y, 1 );
raycaster.set( camera.position, vector.sub( camera.position ).normalize() );
var intersects = raycaster.intersectObjects(scene.children );
if(intersects.length > 0){
console.log(intersects[0].object.position);
}
}
function animate() {
requestAnimationFrame(animate);
render();
}
function render() {
renderer.render(scene, camera);
}

Projector and Ray with OrthographicCamera

Is it possible to use Projector and Ray with OrthographicCamera?
I searched for it but I didn't find any example or documents.
Also my Camera isn't set in center of screen.
camera = new THREE.OrthographicCamera(0, width, 0, height, orthonear, orthofar);
That mean top left will be (0 ,0).
So I don't think below code works correctly.
mouse.x = ( event.clientX / width ) * 2 - 1;
mouse.y = -( event.clientY / height) * 2 + 1;
So how can I use Projector and Ray with OrthographicCamera or any other methods to interact with objects?

Original example:
http://mrdoob.github.com/three.js/examples/webgl_interactive_voxelpainter.html
Use the DAT.GUI controls on the right to change the camera to Orthographic...
A little snippet from the code:
ray = projector.pickingRay( mouse2D.clone(), camera );
var intersects = ray.intersectObjects( scene.children );

Detect clicked object in THREE.js

I have a THREE.js scene where a lot of elements appear, and I need to detect what object the user is clicking on.
What I have done so far is the following. The camera does not move to much - it only changes the vertical position by a limited amount, always looking towards the same point. My approximate method is the following:
I take the coordinates if the click relative to the canvas
I translate them into horizontal and vertical coordinates in the webGL scene by means of a simple rescaling, and add a Z coordinate which is sufficiently far away.
I take a horizontal ray starting from the point above, constructed by THREE.Ray()
I use ray.intersectObjects() to find the first element along the ray.
This method approximately works, but it is sometimes a few pixels away from the actual point.
Is there a more reliable technique to find out the object where a user has clicked?

Depends on what kind of camera are you using.
1) PerspectiveCamera: is ok link that Mr.doob provides.
2) OrthographicCamera: is quite different:
var init = function() {
camera = new THREE.OrthographicCamera( SCREEN_WIDTH / - 2, SCREEN_WIDTH / 2, SCREEN_HEIGHT / 2, SCREEN_HEIGHT / - 2, NEAR, FAR);
document.addEventListener( 'mousedown', onDocumentMouseDown, false );
}
function onDocumentMouseDown( e ) {
e.preventDefault();
var mouseVector = new THREE.Vector3();
mouseVector.x = 2 * (e.clientX / SCREEN_WIDTH) - 1;
mouseVector.y = 1 - 2 * ( e.clientY / SCREEN_HEIGHT );
var raycaster = projector.pickingRay( mouseVector.clone(), camera );
var intersects = raycaster.intersectObject( TARGET );
for( var i = 0; i < intersects.length; i++ ) {
var intersection = intersects[ i ],
obj = intersection.object;
console.log("Intersected object", obj);
}
}

Check out this one:
var camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 1, 5000);
var object; //your object
document.addEventListener('mousedown', onMouseDown, false);
function onMouseDown(e) {
var vectorMouse = new THREE.Vector3( //vector from camera to mouse
-(window.innerWidth/2-e.clientX)*2/window.innerWidth,
(window.innerHeight/2-e.clientY)*2/window.innerHeight,
-1/Math.tan(22.5*Math.PI/180)); //22.5 is half of camera frustum angle 45 degree
vectorMouse.applyQuaternion(camera.quaternion);
vectorMouse.normalize();
var vectorObject = new THREE.Vector3(); //vector from camera to object
vectorObject.set(object.x - camera.position.x,
object.y - camera.position.y,
object.z - camera.position.z);
vectorObject.normalize();
if (vectorMouse.angleTo(vectorObject)*180/Math.PI < 1) {
//mouse's position is near object's position
}
}

Checks for intersection of the mouse and any of the Cubes in 3d space and alters it's color. Maybe this help you.

I ran into problems trying to implement this for a canvas which does not take up the entire width and height of the screen. Here is the solution I found works quite well.
Initialize everything on an existing canvas:
var init = function() {
var canvas_model = document.getElementById('model')
var viewSize = 50 // Depending on object size, canvas size etc.
var camera = new THREE.OrthographicCamera(-canvas_model.clientWidth/viewSize, canvas_model.clientWidth/viewSize, canvas_model.clientHeight/viewSize, -canvas_model.clientHeight/viewSize, 0.01, 2000),
}
Add an event listener to the canvas:
canvas_model.addEventListener('click', function(event){
var bounds = canvas_model.getBoundingClientRect()
mouse.x = ( (event.clientX - bounds.left) / canvas_model.clientWidth ) * 2 - 1;
mouse.y = - ( (event.clientY - bounds.top) / canvas_model.clientHeight ) * 2 + 1;
raycaster.setFromCamera( mouse, camera );
var intersects = raycaster.intersectObjects(scene.children, true);
if (intersects.length > 0) {
// Do stuff
}
}, false)
Or for a 'touchstart' event, change the lines calculating the mouse.x and mouse.y into:
mouse.x = ( (event.touches[0].clientX - bounds.left) / canvas_model.clientWidth ) * 2 - 1;
mouse.y = - ( (event.touches[0].clientY - bounds.top) / canvas_model.clientHeight ) * 2 + 1;