GLTF - how are joints supposed to be transformed during an animation - animation

I'm trying to implement skeletal animation using gltf 2.0 assets.
I'm currently able to transform the skeleton and correctly render the model. The model moves as expected when a transform (for exmaple a rotation) of a joint is edited.
The problem is that as soon as I try to use the transforms from the animation sampler outputs, the skeleton is completely wrong. My testing shows that the transformation matrices of the first keyframe of the animation would match the transform of the joints in the initial pose, but they're in fact quite different ! It's not exactly clear to me where exactly these transforms are supposed to fit in the rendering algorithm.
My rendering algorithm looks roughly like this:
render_scene() {
render_node(root_node, transform::IDENTIY)
}
render_node(node, outer_transform) {
next_transform = outer_transform * node.transform
if (node.has_skin) {
update_joint_matrices(next_transform, node.joints)
}
if (node.has_mesh) {
// draw calls
}
for child in node.children {
render_node(child, next_transform)
}
}
update_joint_matrices(outer_transform, joints) {
world_transforms = []
// Parent nodes are always processed before child nodes
for joint in joints {
if joint.is_root {
world_transforms[joint] = outer_transform * joint.transform
} else {
world_transforms[joint] = world_transforms[joint.parent] * joint.transform
}
}
joint_matrices = []
for joint in 0..world_transforms.len() {
joint_matrices[joint] = world_transforms[joint] * inverse_bind_matrices[joint]
}
// send joint matrices to the GPU
}
The relevant part of the vertex shader looks like this:
void main() {
mat4 modelTransform;
modelTransform =
(inWeights.x * jointMatrices[int(inJoints.x)]) +
(inWeights.y * jointMatrices[int(inJoints.y)]) +
(inWeights.z * jointMatrices[int(inJoints.z)]) +
(inWeights.w * jointMatrices[int(inJoints.w)]);
}
gl_Position = projection * view * modelTransform * vec4(inPos, 1.0);
}
Also, there's a note in the spec I don't quite understand:
Only the joint transforms are applied to the skinned mesh; the transform of the skinned mesh node MUST be ignored.

Ok, I solved the problem.
The issue was that I wasn't loading quaternions correctly.
Quaternions should be interpreted as raw XYZW values.

Related

Changing the Speed of a motor in Processing/box2D

I've been making some simple games using processing and box2D using The Nature of Code as a resource.
My problem is I have gotten to a point where I have these windmills that go clockwise/counterclockwise depending on the speed of the motor (I am using PI/2 and -PI*2). I want to have it so that the user can change this speed from positive and negative by pressing a key or mouse button. Looking around online people and the box2D documentation are saying to use the function void SetMotorSpeed(float speed);, however I am not having luck figuring out how to implement this. I've tried a few ways I can think but no luck.
Currently I have this in my main file ("s" is the name of the instance of the windmill):
// Click the mouse to switch speed of motor
void mousePressed() {
s.SetMotorSpeed(s.speed);
}
And I have this in the file for the windmill:
//Set Motor Speed
void SetMotorSpeed(float speed){
speed = speed * -1;
}
This doesn't work though.
I'm fairly new to coding and this is my first post on stack-overflow so my apologies if I have done anything wrong in how I'm asking or presenting this question. I'm open to suggestions both code and etiquette wise!
Here is the code for the entire windmill:
class Seesaw {
// object is two boxes and one joint
RevoluteJoint joint;
// float speed = PI*2;
Box box1;
Box box2;
float speed = PI*2;
Seesaw(float x, float y) {
// Initialize locations of two boxes
box1 = new Box(x, y-20, 120, 10, false);
box2 = new Box(x, y, 10, 40, true);
// Define joint as between two bodies
RevoluteJointDef rjd = new RevoluteJointDef();
Vec2 offset = box2d.vectorPixelsToWorld(new Vec2(0, 60));
rjd.initialize(box1.body, box2.body, box1.body.getWorldCenter());
// Turning on a motor (optional)
rjd.motorSpeed = PI*2; // how fast?
rjd.maxMotorTorque = 1000.0; // how powerful?
rjd.enableMotor = true; // is it on?
// Create joint
joint = (RevoluteJoint) box2d.world.createJoint(rjd);
}
// Turn the motor on or off
void toggleMotor() {
joint.enableMotor(!joint.isMotorEnabled());
}
boolean motorOn() {
return joint.isMotorEnabled();
}
void SetMotorSpeed(float speed){
speed = -speed;
}
void display() {
box2.display();
box1.display();
// Draw anchor just for debug
Vec2 anchor = box2d.coordWorldToPixels(box1.body.getWorldCenter());
fill(255, 0, 0);
stroke(0);
ellipse(anchor.x, anchor.y, 4, 4);
}
}
The change in speed should be communicated to the joint. Try this:
void SetMotorSpeed(float speed) {
s.joint.setMotorSpeed(speed); // edited, processing/java uses camel-case
}
you might also be a bit more careful about naming variables. In your original post you use the same name for the local variable and the member variable, which has not the wanted effect. Most people use some naming convention for member variable to avoid this kind of very common error. Like for instance have all member variables all start with "_"
void SetMotorSpeed(float speed) {
_speed = -speed; // speed is local!
}

How to keep image original in QgraphicsView in QT

I have load an image in QGraphicsView, but consider of the size of QGraphicsView scene, I need to scale the image first, then add the scaled image to scene.
e.g. The image original size is 1536*1024, the QGraphicsView size is 500*400, firstly I scale the image like this:
image2D = image2D.scaled( h * P , h, Qt::KeepAspectRatioByExpanding, Qt::SmoothTransformation);
myScene->setSceneRect((h * P-w)/2, 0, h * P , h);
pixmapItem = new QGraphicsPixmapItem(image2D);
myScene->addItem(pixmapItem);
myView->setScene(myScene);
And now a problem comes to me, when wheelEvent happends and the QGraphicsView zoom in, the scaled image becomes indistinct while I want it to keep as clear as the original one.
I find a way that I can hold an original copy of image, then when wheelEvent happend just scale the original copy and put it to scene.
But I don't know how to write this code, thanks for help~
or are there any simple methods?
class interactiveView : public QGraphicsView
{
protected:
void wheelEvent(QWheelEvent *event) override;
}
void interactiveView::wheelEvent(QWheelEvent *event)
{
int scrollAmount = event->delta();
xPos = event->pos().x();
yPos = event->pos().y();
scrollAmount > 0 ? zoomIn() : zoomOut();
}
Update:
I find a simple way like this:
just use QGraphicsView::fitInView() to make sure that the image scale is equal to QGraphicsView, and do not need to scale image first.
Therefore the image won't be indistinct when zoom in, and I only need to recall the QGraphicsView::fitInView() to reset to original view instead of using QGraphicsView::resetMatrix()
void myImageWindow::loadImag(int w, int h)
{
pixmapItem->setPixmap(image2D);
//if the scale of image changed
if(image2D.height() != imgHeight_pre){
myView->fitInView(pixmapItem, Qt::KeepAspectRatioByExpanding);
imgHeight_pre = image2D.height();
}
//if the scene of QGraphicsView changed
if(h != sceneHeight_pre){
myView->fitInView(pixmapItem, Qt::KeepAspectRatioByExpanding);
sceneHeight_pre = h;
}
}
void myImageWindow::on_rstImgBtn_clicked()
{
myView->fitInView(pixmapItem, Qt::KeepAspectRatioByExpanding);
}
Scaled image:
becomes indistinct when zoom in:
You can use this method resetMatrix() to reset image
For example:
graphicsView->scale(2, 2);
graphicsView->resetMatrix();
graphicsView->scale(1, 1);

Networking rotation sync

My Unity version is 5.2.3f1, I m trying to sync the rotation of a child gameobject, in local works perfectly fine but it doesnt show up in other clients. I tried everything I could find and nothing.
The reason of this is to rotate a FPS body, so, I m trying to rotate Spine2 (Rotate the camera is not my best solution). I m using a Mixamo character to test, in the end I will have Mixamo auto-rigged charscters so everything I make here will be compatible.
I tried to use the Network Transform Rigidbody 3D and it only sync the character itself, not Spine2, I have tried Network Transform Child, and an official skeleton sync.
In the script part, I have tried a lot of things, the most promising one was this:
[SyncVar]
private Quaternion syncPlayerRotation;
[SerializeField]
private Transform playerTransform;
[SerializeField]
private float lerpRate = 15f;
// Use this for initialization
void Start () {
}
// Update is called once per frame
void LateUpdate () {
TransmitRotations();
LerpRotations();
}
void LerpRotations()
{
if (!isLocalPlayer)
playerTransform.localRotation = Quaternion.Lerp(playerTransform.localRotation, syncPlayerRotation, Time.deltaTime * lerpRate);
}
[Command]
void CmdProvideRotationsToServer(Quaternion playerRot)
{
syncPlayerRotation = playerRot;
}
[Client]
void TransmitRotations()
{
if (isLocalPlayer)
{
CmdProvideRotationsToServer(playerTransform.localRotation);
}
}
Its from UNET tutorial series on youtube, Gamer To Game Developer user.
I attached it to Spine2 and still dont work, but when I attached it to the main character, it worked.
Also tried this:
void OnSerializeNetworkView(BitStream stream, NetworkMessageInfo info)
{
Vector3 syncPosition = Vector3.zero;
if (stream.isWriting)
{
syncPosition = Spine.GetComponent<Rigidbody>().position;
stream.Serialize(ref syncPosition);
}
else
{
stream.Serialize(ref syncPosition);
Spine.GetComponent<Rigidbody>().position = syncPosition;
}
}
But I think it was for an older version of Unity.
To make the rotations I m using A Free Simple Smooth Mouselook
I edited it, this lines:
if (Input.GetMouseButton(1))
{
var xRotation = Quaternion.AngleAxis(-_mouseAbsolute.y, targetOrientation * Vector3.forward);
transform.localRotation = xRotation;
}
else
{
var xRotation = Quaternion.AngleAxis(-_mouseAbsolute.y, targetOrientation * Vector3.right);
transform.localRotation = xRotation;
}
Basicly, I changed Vector3.right to Vector3.forward and converted the Vector3.right only if the right mouse button is not pressed. The script is attached to Spine2 and its activated on the start if(isLocalPlayer) by script.
There's a pic of the current hierarchy:
(some cameras are there only to test, the main camera is FirstPersonCamera, extracted from the standard assets)
I noticed that if I debug log the Spine2 rotation, it only gives me values from 0 to 1.

Rotation in Unity3D

This is a simplified code from what I'm trying to do:
var angle = 1.57;
if ( this.transform.rotation.y > angle ){
this.transform.rotation.y--;
} else if ( this.transform.rotation.y < angle ){
this.transform.rotation.y++;
}
I'm used to code in AS3, and if I do that in flash, it works perfectly, though in Unity3D it doesn't, and I'm having a hard time figuring out why, or how could I get that effect.
Can anybody help me? Thanks!
edit:
my object is a rigidbody car with 2 capsule colliders driving in a "bumpy" floor, and at some point he just loses direction precision, and I think its because of it's heirarchical rotation system.
(thanks to kay for the transform.eulerAngles tip)
transform.rotation retrieves a Quaternion. Try transform.rotation.eulerAngles.y instead.
Transform Rotation is used for setting an angle, not turning an object, so you would need to get the rotation, add your change, and then set the new rotation.
Try using transform.rotate instead.
Check the Unity3d scripting reference here:
http://unity3d.com/support/documentation/ScriptReference/Transform.Rotate.html
I see two problems so far. First the hierarchical rotation of Unity. Based on what you are trying to achieve you should manipulate either
transform.localEulerAngles
or
transform.eulerAngles
The second thing is, you can't modify the euler angles this way, as the Vectors are all passed by value:
transform.localEulerAngles.y--;
You have to do it this way:
Vector3 rotation = transform.localEulerAngles;
rotation.y--;
transform.localEulerAngles = rotation;
You need to create a new Quaternion Object
transform.rotation = Quaternion.Euler ( transform.rotation.x, transform.rotation.y++, transform.rotation.z );
You can also use transform.Rotate function.
The above suggestion to use transform.Rotate( ) is probably what you're going to need to do to actually make it rotate, BUT the variables of transform.Rotate( ) are velocity/speed rather than direction, so transform.Rotate( ) will have to use more than one axis if you want an angled rotation. Ex:
class Unity // Example is in C#
{
void Update( )
{
gameObject.transform.Rotate(0, 1, 0);
}
}
This will rotate the object around its y-axis at a speed of 1.
Let me know if this helps - and if it hinders I can explain it differently.
You should try multiplyng your rotation factor with Time.deltaTime
Hope that helps
Peace
Here is my script for GameObject rotation with touch
//
// RotateController.cs
//
// Created by Ramdhan Choudhary on 12/05/13.
//
using UnityEngine;
using System;
public class RotateController
{
private float RotationSpeed = 9.5f;
private const float mFingerDistanceEpsilon = 1.0f;
public float MinDist = 2.0f;
public float MaxDist = 50.0f;
private Transform mMoveObject = null;
private bool isEnabledMoving = false;
//************** Rotation Controller Constructor **************//
public RotateController (Transform goMove)
{
isEnabledMoving = true;
mMoveObject = goMove;
if (mMoveObject == null) {
Debug.LogWarning ("Error! Cannot find object!");
return;
}
}
//************** Handle Object Rotation **************//
public void Update ()
{
if (!isEnabledMoving && mMoveObject != null) {
return;
}
Vector3 camDir = Camera.main.transform.forward;
Vector3 camLeft = Vector3.Cross (camDir, Vector3.down);
// rotate
if (Input.touchCount == 1) {
mMoveObject.Rotate (camLeft, Input.touches [0].deltaPosition.y * RotationSpeed * Time.deltaTime, Space.World);
mMoveObject.Rotate (Vector3.down, Input.touches [0].deltaPosition.x * RotationSpeed * Time.deltaTime, Space.Self);
}
}
}

Creating a 3D free-camera in WebGL - why do neither of these methods work?

EDIT
OK, I've tried a camera using quaternions:
qyaw = [Math.cos(rot[0]/2), 0, Math.sin(rot[0]/2), 0];
qpitch = [Math.cos(rot[1]/2), 0, 0, Math.sin(rot[1]/2)];
rotQuat = quat4.multiply (qpitch, qyaw);
camRot = quat4.toMat4(rotQuat);
camMat = mat4.multiply(camMat,camRot);
and I get exactly the same problem. So I'm guessing it's not gimbal lock. I've tried changing the order I multiply my matrices, but it just goes camera matrix * model view matrix, then object matrix * model view. That's right isn't it?
I'm trying to build a 3d camera in webGL that can move about the world and be rotated around the x and y (right and up) axes.
I'm getting the familiar problem (possibly gimbal lock?) that once one of the axes is rotated, the rotation around the other is screwed up; for example, when you rotate around the Y axis 90degrees, rotation around the x becomes a spin around z.
I appreciate this is a common problem, and there are copious guides to building a camera that avoid this problem, but as far as I can tell, I've implemented two different solutions and I'm still getting the same problem. Frankly, it's doing my head in...
One solution I'm using is this (adapted from http://www.toymaker.info/Games/html/camera.html):
function updateCam(){
yAx = [0,1,0];
xAx = [1,0,0];
zAx = [0,0,1];
mat4.identity(camMat);
xRotMat = mat4.create();
mat4.identity(xRotMat)
mat4.rotate(xRotMat,rot[0],xAx);
mat4.multiplyVec3(xRotMat,zAx);
mat4.multiplyVec3(xRotMat,yAx);
yRotMat = mat4.create();
mat4.identity(yRotMat)
mat4.rotate(yRotMat,rot[1],yAx);
mat4.multiplyVec3(yRotMat,zAx);
mat4.multiplyVec3(yRotMat,xAx);
zRotMat = mat4.create();
mat4.identity(zRotMat)
mat4.rotate(zRotMat,rot[2],zAx);
mat4.multiplyVec3(zRotMat,yAx);
mat4.multiplyVec3(zRotMat,xAx);
camMat[0] = xAx[0];
camMat[1] = yAx[0];
camMat[2] = zAx[0];
//camMat[3] =
camMat[4] = xAx[1]
camMat[5] = yAx[1];
camMat[6] = zAx[1];
//camMat[7] =
camMat[8] = xAx[2]
camMat[9] = yAx[2];
camMat[10]= zAx[2];
//camMat[11]=
camMat[12]= -1* vec3.dot(camPos, xAx);
camMat[13]= -1* vec3.dot(camPos, yAx);
camMat[14]= -1* vec3.dot(camPos, zAx);
//camMat[15]=
var movSpeed = 1.5 * forward;
var movVec= vec3.create(zAx);
vec3.scale(movVec, movSpeed);
vec3.add(camPos, movVec);
movVec= vec3.create(xAx);
movSpeed = 1.5 * strafe;
vec3.scale(movVec, movSpeed);
vec3.add(camPos, movVec);
}
I also tried using this method using
mat4.rotate(camMat, rot[1], yAx);
instead of explicitly building the camera matrix - same result.
My second (actually first...) method looks like this (rot is an array containing the current rotations around x, y and z (z is always zero):
function updateCam(){
mat4.identity(camRot);
mat4.identity(camMat);
camRot = fullRotate(rot);
mat4.set(camRot,camMat);
mat4.translate(camMat, camPos);
}
function fullRotate(angles){
var cosX = Math.cos(angles[0]);
var sinX = Math.sin(angles[0]);
var cosY = Math.cos(angles[1]);
var sinY = Math.sin(angles[1]);
var cosZ = Math.cos(angles[2]);
var sinZ = Math.sin(angles[2]);
rotMatrix = mat4.create([cosZ*cosY, -1*sinZ*cosX + cosZ*sinY*sinX, sinZ*sinX+cosZ*sinY*cosX, 0,
sinZ*cosY, cosZ*cosX + sinZ*sinY*sinX, -1*cosZ*sinX + sinZ*sinY*cosX, 0,
-1*sinY, cosY*sinX, cosY*cosX, 0,
0,0,0,1 ] );
mat4.transpose(rotMatrix);
return (rotMatrix);
}
The code (I've taken out most of the boilerplate gl lighting stuff etc and just left the transformations) to actually draw the scene is:
function drawScene() {
gl.viewport(0, 0, gl.viewportWidth, gl.viewportHeight);
gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
mat4.perspective(45, gl.viewportWidth / gl.viewportHeight, 0.1, 2000.0, pMatrix);
mat4.identity(mvMatrix);
for(var i=0; i<planets.length; i++){
if (planets[i].type =="sun"){
currentProgram = perVertexSunProgram;
} else {
currentProgram = perVertexNormalProgram;
}
alpha = planets[i].alphaFlag;
mat4.identity(planets[i].rotMat);
mvPushMatrix();
//all the following puts planets in orbit around a central sun, but it's not really relevant to my current problem
var rot = [0,rotCount*planets[i].orbitSpeed,0];
var planetMat;
planetMat = mat4.create(fullRotate(rot));
mat4.multiply(planets[i].rotMat, planetMat);
mat4.translate(planets[i].rotMat, planets[i].position);
if (planets[i].type == "moon"){
var rot = [0,rotCount*planets[i].moonOrbitSpeed,0];
moonMat = mat4.create(fullRotate(rot));
mat4.multiply(planets[i].rotMat, moonMat);
mat4.translate(planets[i].rotMat, planets[i].moonPosition);
mat4.multiply(planets[i].rotMat, mat4.inverse(moonMat));
}
mat4.multiply(planets[i].rotMat, mat4.inverse(planetMat));
mat4.rotate(planets[i].rotMat, rotCount*planets[i].spinSpd, [0, 1, 0]);
//this bit does the work - multiplying the model view by the camera matrix, then by the matrix of the object we want to render
mat4.multiply(mvMatrix, camMat);
mat4.multiply(mvMatrix, planets[i].rotMat);
gl.useProgram(currentProgram);
setMatrixUniforms();
gl.drawElements(gl.TRIANGLES, planets[i].VertexIndexBuffer.numItems, gl.UNSIGNED_SHORT, 0);
mvPopMatrix();
}
}
However, most of the transformations can be ignored, the same effect cab be seen simply displaying a sphere at world coords 0,0,0.
I thought my two methods - either rotating the axes one at a time as you go, or building up the rotation matrix in one go avoided the problem of doing two rotations one after the other. Any ideas where I'm going wrong?
PS - I'm still very much starting to learn WebGL and 3d maths, so be gentle and talk to me like someone who hadn't heard of a matrix til a couple of months ago... Also, I know quaternions are a good solution to 3d rotation, and that would be my next attempt, however, I think I need to understand why these two methods don't work first...
For the sake of clarification, think about gimbal lock this way: You've played Quake/Unreal/Call of Duty/Any First Person Shooter, right? You know how when you are looking forward and move the mouse side to side your view swings around in a nice wide arc, but if you look straight up or down and move your mouse side to side you basically just spin tightly around a single point? That's gimbal lock. It's something that pretty much any FPS game uses because it happens to mimic what we would do in real life, and thus most people don't usually think of it as a problem.
For something like a space flight sim, however, or (more commonly) skeletal animation that type of effect is undesirable, and so we use things like quaternions to help us get around it. Wether or not you care about gimbal lock for your camera depends on the effect that you are looking to achieve.
I don't think you're experiencing that, however. What it sounds like is that your order of matrix multiplication is messed up, and as a result your view is rotating in a way that you don't expect. I would try playing with the order that you do your X/Y/Z rotations in and see if you can find an order than gives you the desired results.
Now, I hate doing code dumps, but this may be useful to you so here we go: This is the code that I use in most of my newer WebGL projects to manage a free-floating camera. It is gimbal locked, but as I mentioned earlier it doesn't really matter in this case. Basically it just gives you FPS style controls that you can use to fly around your scene.
/**
* A Flying Camera allows free motion around the scene using FPS style controls (WASD + mouselook)
* This type of camera is good for displaying large scenes
*/
var FlyingCamera = Object.create(Object, {
_angles: {
value: null
},
angles: {
get: function() {
return this._angles;
},
set: function(value) {
this._angles = value;
this._dirty = true;
}
},
_position: {
value: null
},
position: {
get: function() {
return this._position;
},
set: function(value) {
this._position = value;
this._dirty = true;
}
},
speed: {
value: 100
},
_dirty: {
value: true
},
_cameraMat: {
value: null
},
_pressedKeys: {
value: null
},
_viewMat: {
value: null
},
viewMat: {
get: function() {
if(this._dirty) {
var mv = this._viewMat;
mat4.identity(mv);
mat4.rotateX(mv, this.angles[0]-Math.PI/2.0);
mat4.rotateZ(mv, this.angles[1]);
mat4.rotateY(mv, this.angles[2]);
mat4.translate(mv, [-this.position[0], -this.position[1], - this.position[2]]);
this._dirty = false;
}
return this._viewMat;
}
},
init: {
value: function(canvas) {
this.angles = vec3.create();
this.position = vec3.create();
this.pressedKeys = new Array(128);
// Initialize the matricies
this.projectionMat = mat4.create();
this._viewMat = mat4.create();
this._cameraMat = mat4.create();
// Set up the appropriate event hooks
var moving = false;
var lastX, lastY;
var self = this;
window.addEventListener("keydown", function(event) {
self.pressedKeys[event.keyCode] = true;
}, false);
window.addEventListener("keyup", function(event) {
self.pressedKeys[event.keyCode] = false;
}, false);
canvas.addEventListener('mousedown', function(event) {
if(event.which == 1) {
moving = true;
}
lastX = event.pageX;
lastY = event.pageY;
}, false);
canvas.addEventListener('mousemove', function(event) {
if (moving) {
var xDelta = event.pageX - lastX;
var yDelta = event.pageY - lastY;
lastX = event.pageX;
lastY = event.pageY;
self.angles[1] += xDelta*0.025;
while (self.angles[1] < 0)
self.angles[1] += Math.PI*2;
while (self.angles[1] >= Math.PI*2)
self.angles[1] -= Math.PI*2;
self.angles[0] += yDelta*0.025;
while (self.angles[0] < -Math.PI*0.5)
self.angles[0] = -Math.PI*0.5;
while (self.angles[0] > Math.PI*0.5)
self.angles[0] = Math.PI*0.5;
self._dirty = true;
}
}, false);
canvas.addEventListener('mouseup', function(event) {
moving = false;
}, false);
return this;
}
},
update: {
value: function(frameTime) {
var dir = [0, 0, 0];
var speed = (this.speed / 1000) * frameTime;
// This is our first person movement code. It's not really pretty, but it works
if(this.pressedKeys['W'.charCodeAt(0)]) {
dir[1] += speed;
}
if(this.pressedKeys['S'.charCodeAt(0)]) {
dir[1] -= speed;
}
if(this.pressedKeys['A'.charCodeAt(0)]) {
dir[0] -= speed;
}
if(this.pressedKeys['D'.charCodeAt(0)]) {
dir[0] += speed;
}
if(this.pressedKeys[32]) { // Space, moves up
dir[2] += speed;
}
if(this.pressedKeys[17]) { // Ctrl, moves down
dir[2] -= speed;
}
if(dir[0] != 0 || dir[1] != 0 || dir[2] != 0) {
var cam = this._cameraMat;
mat4.identity(cam);
mat4.rotateX(cam, this.angles[0]);
mat4.rotateZ(cam, this.angles[1]);
mat4.inverse(cam);
mat4.multiplyVec3(cam, dir);
// Move the camera in the direction we are facing
vec3.add(this.position, dir);
this._dirty = true;
}
}
}
});
This camera assumes that Z is your "Up" axis, which may or may not be true for you. It's also using ECMAScript 5 style objects, but that shouldn't be an issue for any WebGL-enabled browser, and it utilizes my glMatrix library but it looks like you're already using that anyway. Basic usage is pretty simple:
// During your init code
var camera = Object.create(FlyingCamera).init(canvasElement);
// During your draw loop
camera.update(16); // 16ms per-frame == 60 FPS
// Bind a shader, etc, etc...
gl.uniformMatrix4fv(shaderUniformModelViewMat, false, camera.viewMat);
Everything else is handled internally for you, including keyboard and mouse controls. May not fit your needs exactly, but hopefully you can glean what you need to from there. (Note: This is essentially the same as the camera used in my Quake 3 demo, so that should give you an idea of how it works.)
Okay, that's enough babbling from me for one post! Good luck!
It doesn't matter how you build your matrices, using euler angle rotations (like both of your code snippets do) will always result in a transformation that shows the gimble lock problem.
You may want to have a look at https://en.wikipedia.org/wiki/Quaternions_and_spatial_rotation as a starting point for creating transformations that avoid gimble locks.
Try my new project (webGL2 part of visual-js game engine) based on glmatrix 2.0 .
Activate events for camera use : App.camera.FirstPersonController = true;
live examples
For camera important functions :
Camera interaction
App.operation.CameraPerspective = function() {
this.GL.gl.viewport(0, 0, wd, ht);
this.GL.gl.clear(this.GL.gl.COLOR_BUFFER_BIT | this.GL.gl.DEPTH_BUFFER_BIT);
// mat4.identity( world.mvMatrix )
// mat4.translate(world.mvMatrix , world.mvMatrix, [ 10 , 10 , 10] );
/* Field of view, Width height ratio, min distance of viewpoint, max distance of viewpoint, */
mat4.perspective(this.pMatrix, degToRad( App.camera.viewAngle ), (this.GL.gl.viewportWidth / this.GL.gl.viewportHeight), App.camera.nearViewpoint , App.camera.farViewpoint );
};
manifest.js :
var App = {
name : "webgl2 experimental",
version : 0.3,
events : true,
logs : false ,
draw_interval : 10 ,
antialias : false ,
camera : { viewAngle : 45 ,
nearViewpoint : 0.1 ,
farViewpoint : 1000 ,
edgeMarginValue : 100 ,
FirstPersonController : false },
textures : [] , //readOnly in manifest
tools : {}, //readOnly in manifest
download source from :
webGL 2 part of visual-js GE project
Old :
opengles 1.1
https://stackoverflow.com/a/17261523/1513187
Very fast first person controler with glmatrix 0.9 based on http://learningwebgl.com/ examples.

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