What I have is an OrthographicCamera set up so that is has an isometric view of the scene and OrbitConrols added to allow for panning around and zooming but not for rotation.
What I’d like to have is a button that will centre the objects in a scene and zoom the OrthographicCamera so that the objects fit within the canvas area while keeping the isometric view, i.e. the angle between the camera.position and the camera.lookAt (control.target) point.
What I’ve tried is to set the controls.target at the centre of the bounding box of the objects in the scene.
I have 2 problems with the code at the moment.
The First is I couldn’t work out how to calculate the zoom level needed to make sure the objects in the scene are all in view. I’ve hard coded a value for just now.
The Second is that with the current code, if the camera is panned so that the objects appear nearly off the screen, either up or down, then when centred the angle of the camera changes. This was happening when the camera was panned far left or right but setting the max and min Azimuth Angle seems to prevent this.
camera rotates after centring
The image above shows the scene when loaded then after centering when the camera was panned so the objects were going off the top of the screen.
I have tried a number of ways to do this after looking at answers to similar questions as this but am still having problems getting it to work.
function fitDrawingToPage(){
// Variables Bbox etc are set outside the function
Bbox = new THREE.Box3();
for (const object of sceneObjects) Bbox.expandByObject(object);
newTarget = Bbox.getCenter(new THREE.Vector3());
controls.target.set( newTarget.x, newTarget.y, newTarget.z );
controls.update();
camera.zoom = 0.5;
camera.updateProjectionMatrix();
camera.updateMatrix();
render();
}
current example of code in jsfiddle
Related
I have created a raytracing algorithm which currently displays a triangle on screen, and am now having trouble moving the camera around correctly.
I would like my code to have the arrow keys rotate the camera, and WASD move the camera in 3D space. The camera currently rotates correctly using two rotation matrices for y and z rotations.
The Problem
Moving the camera, rather than rotating, is where the issue arises. To move the camera, I require two vectors - cameraForward and cameraRight. These vectors can be added on to the position of the camera when input is detected. These vectors will also need to change when the cemara is rotated, in the same rotation as all the rays experience. But when I apply these rotation matrices to the vectors representing cameraRight and cameraForward, there seems to be an issue. Holding down the A or D key will result in the camera moving unexpectedly in circles or odd wavy lines.
I managed to fix the issue with cameraForward by using a different method. I added a couple lines of code which calculate when the ray at the centre as been 'fired' and proceed to set cameraForward to that ray. Therefore cameraForward will always follow the central ray being sent out i.e. the centre of the field of view. However, I cannot do the same with cameraRight, as this vector is not in the field of view.
Before solving cameraForward using this method the same issue arose with moving forwards and backwards.
I also tried taking the cross product of one of the other rays along with the cameraForward vector which I thought might produce cameraRight, but to no avail - more sporadic camera movement
I do not have the vector for cameraUp either so cannot calculate the cross product to find cameraRight.
I also thought maybe the code was being run too many times and the vector was rotated multiple times. However mvoing the code elsewhere had no effect and the method it was already in is run every frame, so I do not believe that is the issue.
Here is my code to rotate the camera right and the method which does the rotation.
camRight's inital value is (0, 0, 1)
camRight = normalize(rotateVector(camRight, rotationZ));
camRight = normalize(rotateVector(camRight, rotationY));
function rotateVector(v, m) {
return new Vector3(dot(m.a, v), dot(m.b, v), dot(m.c, v));
}
I know this code works as the code rotating the camera view functions correctly using the same matrices and methods.
(the following code)
myDirection = normalize(rotateVector(myDirection, rotationZ));
myDirection = normalize(rotateVector(myDirection, rotationY));
When the user presses A or D the following code is run
if (keys[65]) {
camPos = add(camPos, normalize(camRight));
requestAnimationFrame(render);
}
if (keys[68]) {
camPos = subtract(camPos, normalize(camRight));
requestAnimationFrame(render);
}
The camera moves forwards and backward correctly, as previously mentioned. Initially, the camera moves left and right correctly too (as its inital value of (0, 0, 1) is correct), but if I rotate the camera, the values for cameraRight go wild.
Have I assumed something wrongly? or is there a flaw in my logic somewhere?
Thank for any help
I want to remove clipping planes in THREE js but I can't seem to find any information on how to do this. What I found is that orthographic camera can have negative value for near clipping plane.
If I put negative value in near clipping plane of perspective camera, it doesn't throw an error but doesn't show any objects.
I draw relatively huge objects and the near clipping plane is very frustrating when I try to explore them as they disapear completely if they are behind the camera even if most of the object should still be visible, is there a way to remove it so my objects always gets drawn?
here is the camera values I use:
var camera = new THREE.PerspectiveCamera(90, size.x/size.y, 0.1, 1000);
When I move, I move the camera instead of all the objects relative to a fixed camera, I guessed it would be more performent, but I don't think it matters for my problem.
All of the objects have position (0, 0, 0) but can have part extending up to 10-15 units away from their position
On a scene I have an object that I'm looking at with a PerspectiveCamera.
Using OrbitControls I can move around the object, rotate it, pan it etc.
What I want to do is move the object around to a certain location with a certain angle and then get the camera position and rotation. I would later update the camera with those values. The problem is that three.js doesn't apply some of those values. Here's what I'm doing to get the camera position, rotation, and the lookAt vector
console.log("Position", camera.position)
console.log("Rotation", camera.rotation)
console.log("World Direction", camera.getWorldDirection())
Once I get the vectors, write them down and apply them like this:
camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 1, 2000);
camera.rotation.set(-3.14, -0.44, -3.14);
camera.position.set(-1067.29, 34.23, 205.82);
camera.lookAt(0.43, -7.10, 0.90)
But the problem is that the rotation and position get changed to some other value if I have used pan with OrbitControls
On Orbitcontrols you need to call "controls.update()" after changes to the camera's transform.
See code-example on OrbitControlDokumentation
Update:
Attention: orbitcontrols seem to overwrite camera transforms
I've searched through many related questions on stack overflow, but I couldn't quite find the answer to this problem.
I have a big, dynamic group of Object3D's in my scene, with an orthographic camera looking at them head-on.
I want to have a simple function which, when called, will simply match the top/left/bottom/right/zoom properties of the Orthographic camera to properly fit the Object3D group.
I've tried all kinds of things, but none of my code is worth posting. I need to look at this from a whole new angle (pun intended). I have found various other answers which discuss changing the fov of the camera, once you know the distance from the face of bounding box of the group to the camera, but I don't know how to implement that with an orthographic camera, since (as far as I've tried) the fov property doesn't work with it (maybe it actually does, I just don't know).
So I don't particularly like asking for code, but nevertheless I would like a function which would automatically adjsut the appropriate properties of the Orthographic camera to fit the object passed to it as a parameter, for example:
function fitOrthographicCameraToObject3DGroup(group) {
//implement here (my question)
}
Calculate the bounding box of your mesh and apply this code.
This works for me
var camera = new THREE.OrthographicCamera(container.offsetWidth / -2, container.offsetWidth / 2, container.offsetHeight / 2, container.offsetHeight / -2, 100, 100000);
//For centering the meshGroup
var box = new THREE.Box3().setFromObject(meshGroup);
box.center(meshGroup.position);
meshGroup.localToWorld(box);
meshGroup.position.multiplyScalar(-1);
//For fitting the object to the screen when using orthographic camera
Camera.zoom = Math.min(container.offsetWidth / (box.max.x - box.min.x),
container.offsetHeight / (box.max.y - box.min.y)) * 0.4;
Camera.updateProjectionMatrix();
Camera.updateMatrix();
Setting the top/left/bottom/right of the orthographic camera once you have the bounding box should not be a problem. Just take the half lengths of the bounding box.
The zoom is the issue and for that you can confine your scene in a unit cube by scaling up or down your scene by the appropriate amount depending on your bounding box size. Then you dont have to worry about the zoom and the above top/left/bottom/right values become 0.5/0.5/-0.5/-0.5.
I am currently creating a VR web app using three.js. As the camera controls I am using the device orientation controls used here in the google cardboard three.js demo.
What I need to do is add keyboard controls to this(e.g Up arrow to go forward etc). I've fiddled around with moving the camera on the two axis (x and z) here:
if (e.keyCode == '38') {
camera.position.set(0, 10, camera.position.z+4);
controls.target.set(
camera.position.x +4,
camera.position.y,
camera.position.z
);
effect.render(scene, camera);
...
However I want to make the character move relative to where they are looking (e.g You look one way and press the Up arrow and the character moves the way you looking). Like a first person view.
Does anyone have any ideas on how this is done? Ive tried using the first person controls from three.js but this eliminates the head tracking which is essential for a VR game.
Any answers would be greatly appreciated. (My source code is practically just the Google cardboard three.js demo code with a function added in too detect key presses)
I solved this by different approach. I created an object3d which is moving in scene. Model and camera are child of this object.
I'm rotating object 3d with camera and in the same time rotate model in opposite direction. When i rotate camera object looks keeping direction. when i want to move object, just translateX object with camera and make model rotation to 0. That did the trick.
On long distances (I have millions of units) started to be jerky. Reason is lost precision.
I solved it by keeping position of object at 0,0,0 and move all other things in opposite direction. That makes your model is still on 0,0,0 coords with right rotation and world is moving around.
Most simple example:
you trying something like
scene.add(character_model);
scene.add(camera);
//camera.rotate ....
character_model.translateX(1);
character_model.rotateX(1);
//etc ...
and now you trying to move camera around the pivot (character_model), but this is overcomplicated mathematics.
Try:
var controls_dimension = new THREE.Object3D();
scene.add(controls_dimension);
controls_dimension.add(character_model);
controls_dimension.add(camera);
//use controls to rotate with this object, not with character_model
controls_dimension.rotateX(2);
// in the same rotate model to opposite direction. You can make
// illusion of rotating camera, not a model.
character_model.rotateX(2*-1);
/*
when you want to go in camera direction=controls_dimension=controls_dimension.translateX(1)
and we moving (you most only animate model rotation to controls_dimension.rotation)
*/