I am playing around with p5js and wanted to create a simple game where the main goal is to jump over objects that are incoming from the right side of the screen.
So, pretty basic idea.
Everything appears to be working so far, however, I would like to increase the speed of objects that keep incoming either over a period of time or after an X amount of objects have passed. Currently, I am storing the objects into an array and looping through them.
Speed is determined by this.speed in the Pipe() function.
In order to show you what I mean, you can check the running version here. ( I had to put all functions into one file in order for this to work online)
FOR GAME CLICK HERE
(the game is played by pressing and/or holding the UP_ARROW)
I was trying to update this.speed from the draw function, but I wasn't able to keep this.speed persistent.
Any help is appreciated.
You would probably need to make a global speed variable so that all pipes are affected accordingly.
A suggestion would be to create an interval which increments speed and then assign that to this.x within the update function of the Pipe object.
this.update = function() {
this.x -= speed;
}
https://jsbin.com/fodekizohi/1/edit?html,js,output
Related
So I want to make a small JavaScript game.
And in order to do that I need to animate a few things.
I went researching and found about setInterval and requestAnimationFrame.
I can use either of those 2 for making my game work, however I understood that requestAnimationFrame is the better alternative there.
The problem I see with this is that while the function has its benefits , you are unable to set a framerate , or an update rate for it easily.
I found another thread that explained a way of making this work however it seemed somewhat complicated.
Controlling fps with requestAnimationFrame?
Is there an easier way of animating with a set framerate ?
Is there an easier way of animating with a set framerate ?
Simply put: no. Since rendering is one of the most computation heavy process for a browser, which can be triggered in various ways, it is not possible to foretell how long an update will take, since it can range from drawing one circle on a canvas up to a complete replace of all the visible content of the page.
To overcome this, browser offer a way to call a function a often as possible and the developer is responsible to make his animation sensitive to different time deltas/time steps.
One way to tackle that is to use the concept of velocity. velocity = distance / time. If you want an asset to have a constant velocity you can do the following, since distance = velocity * time follows:
var
asset_velocity = 1; //pixel per millisecond
last = new Date().getTime()
;
(function loop () {
var
now = new Date().getTime(),
delta = now - last,
distance = asset_velocity * delta
;
//update the asset
last = now;
window.requestAnimationFrame(loop)
})();
I am making an endless runner style game using Three.js. The basic set up of the scene and idea for the game is a long moving road with cars coming towards you that you have to dodge out of the way of. I am still at the early stages of creating this game, and so my first problem is that I need the hero character (who is dodging the cars) to seem like he is moving forwards, and at the same time have the cars seem like they are moving (faster) towards the hero character.
My thinking was to create road strip objects (the white lines in the middle of a road), and have them move towards the hero character, who is at (0, 0), at a certain speed.
I have successfully created a road strip object and positioned it at the very back of the road (RoadStrip.mesh.position.z = -5000;). Here is my code for that:
var objectRoadStrip = function() {
this.mesh = new THREE.Object3D();
this.mesh.name = "roadStrip";
geomRoadStrip = new THREE.BoxGeometry(20, 11, 300);
matRoadStrip = new THREE.MeshPhongMaterial({color: Colors.white});
RoadStrip = new THREE.Mesh(geomRoadStrip, matRoadStrip);
RoadStrip.name = 'roadStripName';
this.mesh.add(RoadStrip);
}
function createRoadStrip() {
new objectRoadStrip();
RoadStrip.position.y = -72.5;
RoadStrip.position.z = -5000;
scene.add(RoadStrip);
}
In the render() function, which is the function that loops over every frame and is called last to make sure the camera and scene update every frame, I am able to successfully move this strip forwards along the z axis by 10 every time render() is called. I also added some code so that when the RoadStrip touches (0,0), it is removed from the scene. See this below:
function render(){
// moves RoadStrip towards (0,0). When it reaches z = -150, remove that strip from the scene
if (RoadStrip.position.z <= -150) {
RoadStrip.position.z += 10;
} else {
scene.remove(RoadStrip);
}
renderer.render(scene, camera);
requestAnimationFrame(render);
}
I have also added the following code to the init() function which creates a RoadStrip when the scene is created, and the continues to create a RoadStrip every 10 seconds (roughly every time the RoadStrip reaches (0,0).
createRoadStrip();
setInterval( function() {
createRoadStrip();
}, 10000);
This is similar to the effect I'm going for, but read The Problem section below where I explain what I truly need.
The Problem
I need to spawn a RoadStrip every x amount of seconds (still to be decided once I get it working, but lets say 3 seconds for now) continuously. Each RoadStrip needs to move towards (0,0) with z += 10 independently. When a RoadStrip instance reaches (0,0), it should be removed from the scene, but other RoadStrips should continue to spawn regardless every 3 seconds at the original position (z = -5000).
My Attempts / Solution Ideas
I've done a lot of reading on this, trawling through code from other people's endless runner games and reading through SO answers but nothing seems to have worked. Below are some of the things I have tried, or some things that I feel would work but I am not doing right/don't have a good understanding of:
Idea: Instead of calling the createRoadStrip() function inside a setInterval, push a RoadStrip object to an array every 3 seconds, and then call that array and move the array along the z axis by += 10.
Possible solution help: I tried changing the setInterval to less than 2 seconds instead of 10 seconds. This caused the RoadStrip to move along the Z axis for 2 seconds as expected, but of course, after 2 seconds another RoadStrip was spawned, and so the first RoadStrip stopped moving along the Z axis, and the new one did instead (for 2 seconds as well) and this process repeated infinitely. This is so close to what I need, but I need each RoadStrip to continue moving, and be remove from the scene when it reaches (0,0)
Thanks for taking the time to read my Question, I look forward to your solutions!
Examples of similar style games: First, Second.
Thanks to #prisoner849 and his link to this thread, I managed to find the solution to the problem, and so I am writing an answer here for anyone who comes across this with the same problem in the future!
I read through the thread and found a link to this JSFiddle, that includes a successful animation similar to the one I was trying to achieve, and I would highly suggest studying the code of that JSFiddle to fully understand how to create an endless runner effect.
Here is a detailed explanation of how to do this:
Instead of infinitely creating objects and have them animate forwards until they reach the end point and disappear (like I originally thought was the right solution), you have to create an array of objects and animate that instead.
Here is my code for doing this:
var roadStripArray = []
function objectRoadStrip() {
for (var i = 0; i < 100; i++) {
geomRoadStrip = new THREE.BoxGeometry(20, 11, 500);
matRoadStrip = new THREE.MeshPhongMaterial({color: Colors.white});
RoadStrip = new THREE.Mesh(geomRoadStrip, matRoadStrip);
RoadStrip.position.set(0, -72.5, -150 - i * 1250);
RoadStrip.receiveShadow = true;
scene.add(RoadStrip);
roadStripArray.push(RoadStrip);
}
}
The for loop has the code i < 100 as my road is quite long and therefore needs a lot of strips
This code:
RoadStrip.position.set(0, -72.5, 0 - i * 1250);
sets the position of each strip to be different from each other, and the number 1250 is the distance between each strip
After creating the objects, you must animate them in the render() function. You have to set them to move along the Z axis, and then create an if statement that says "if any strip reaches the end point (where you want it to disappear), reset it's position back to the start (i.e. the start of the road for me). This means you are constantly looping through your array of objects, and therefore don't infinitely create them.
Here is the code that animates the strips:
// loop that runs every frame to render scene and camera
var clock = new THREE.Clock();
var time = 0;
var delta = 0;
var direction = new THREE.Vector3(0, 0, 1);
var speed = 2000; // units a second - 2 seconds
function render(){
requestAnimationFrame(render);
delta = clock.getDelta();
time += delta;
roadStripArray.forEach(function(RoadStrip){
RoadStrip.position.addScaledVector(direction, speed * delta);
if (RoadStrip.position.z >= 10000) {
RoadStrip.position.z = -10000;
} else {
}
});
renderer.render(scene, camera);
}
The code that moves each strip is:
RoadStrip.position.addScaledVector(direction, speed * delta);
You can read more about .addScaledVector here, but essentially this is the code that animates the strip.
The if statement then checks if the strip touches 10000 (i.e. the end of the road), and if it does, sets the position of that strip to -10000. That strip then moves back towards the end point along the Z axis.
We wrap this all in a forEach function to loop through each RoadStrip in the array and animate them all in the same way. We need to animate them individually so that we can detect when one of them reaches the end of the road.
Thanks, hope this helps!
Usually this kind of scenario is best handled with some kind of particle-system like approach: you don't insert/remove objects continuously to the scene but create a set of objects during initialization, let's say the player can only see 10 road stripes at a time, and your game logic is always moving those 10 stripes, updating positions as needed, once one strip goes out of the field of view, it is recycled at the begining and so on. I don't think you will find a canned solution that does exactly what you are looking for, you would need to come up with the update logic that suits best your game.
I have an example of custom particle system there. Once a particle is getting out of scope, it is made available for the system when it needs to emit a new particle. The number of particle in the pool is always constant and can be defined by the user here just for testing purpose. A similar approach can be used to manipulate your infinite stripes. The repo for that code is available at https://github.com/leefsmp/Particle-System but you can find many other particle system implementations out there, this one is a bit specific to my needs.
Hope that helps.
So I'm using Three.js and I have some cubes inside of a box. I'm using the Transform Control to move the cubes around inside of the box with my mouse. I'd like to use raycasting in order to check for collisions. The question is how to I prevent the transform controller from moving the object if there is a collision? I'd like to stop it if it hits the wall. By the way, I'm on version r81 for Three.js.
UPDATE: I've used the size of the room to constrain the cubes from
moving outside of the room. This seems to work well. Is there a way
to use the cannon.js just for collisions? I don't want the momentum
or gravity or any other feature. JUST the collision check and to stop
it dead in its tracks when there is a collision.
I know this post is from a long time ago, but hopefully a googler finds this helpful. I wasn't able to stop the user from moving my object, but I was able to move it back to its proper position immediately afterward by adding some logic to the render method.
For the original poster's problem with collisions, you could attach an event listener to the transform controls and request the object to be repositioned if it is in an illegal state.
transformControls.addEventListener('objectChange', (e) => {
if (illegalPosition(this.obj.position)) {
needsReset = true;
}
lastPosition = attachedObject.position.clone();
});
and then in your render function
if (needsReset) {
attachedObject.position.set(lastPosition.x, lastPosition.y, lastPosition.z);
}
If this feels a little hacky, that's because it is. But for those of us who don't have the time or skill to read and modify TransformControls.js, I think it may prove helpful.
You could create helper raycaster and place all colliders in separate container. After movement is applied to object move raycaster to its position and test if ray intersects any of other objects in container. If yes: reset previous position for that object. In case of cube colliders you could want to raycast from cube center in multiple directions with half of side length as ray length.
Ben S does have the best and most painless way to implement collision detection with transform controls. Within a event listener.
But I don't know if the time of writing his answer he knew about or if there even was a function called "requestAnimationFrame". All you would have to do for collision detection instead of simply resetting the models position is to set up your render call within a loop (60 fps) by adding "requestAnimationFrame" to your render (I call it animate since that is more descriptive) function.
Since it is in a loop and is called when the every frame the scene is drawn it will just not allow the object to move past the point of collision.
function animate() {
// Called to draw onto screen every frame (60fps).
requestAnimationFrame(animate);
renderer.render(scene, camera);
}
And your event listener would just look like this.
control.addEventListener('objectChange', (e) => {
// Collision detection code here. Set colliding model position here.
// No need to set it in render
});
Old post, I know. But here is a method that is still fairly simple but does not flicker or use ray casting. The biggest catch here is that you have a little bit of a bounce if you move the Transform control really quickly. But otherwise it seems to work fairly well. You can control the precision of the collision by adjusting the step value.
let transStart = null;
//capture objects position on start
control.addEventListener('mouseDown', function(){
transStart = control.object.position.clone();
})
//you'll have to provide your own collision function
control.addEventListener('objectChange', function(e){
if(collision(sphere, cube)){ stopControls() };
});
function stopControls(){
if(control.dragging && stopAt){
//calculate direction object was moving at time of collision
const s = transStart;
const e = control.object.position.clone();
const n = e.clone().sub(s).negate().normalize();
//janky hack nonsense that stops the transform control from
//continuing without making the camera controller go nuts.
control.pointerUp({button:0});
control.dragging = true;
//translate back the direction it came by the step amount and do not
//stop until the objects are no longer colliding.
//Increase the step size if you do not need super precise collision
//detection. It will save calculations.
let step = 0.00005;
while(colliding(sphere, cube)){
sphere.translateOnAxis( n, step ) ;
sphere.updateMatrix();
}
}
}
I need to broadcast position updates in a game-world running with node.js. My current idea is to use BinaryJS. I'm not sure what is the correct way to use it, though. I have thought in 3 options:
How I'm doing currently, using socket.io: I programmatically store a buffer of position-updates that happened in a given amount of time and then send it all at once:
setTimeout(function(){
//called a fixed amount of times per second (40)
//this variable will hold the accumulated position changes on the last 25ms
//var accumulated_position_changes = [id0,x0,y0,z0, id1,x1,y1,z1...];
client.send(accumulated_position_changes);
},25);
But if binary.js does the chunking by itself (does it?), then should I just indiscriminately send position changes every time they happen?
MyClass.prototype.set_position = function(x,y,z){
// this is called thousands times a second
this.x = x, this.y = y, this.z = z;
client.send([this.id, x, y, z]);
};
Or should I somehow create an object deriving node.js's stream and use it? Maybe with stream.write? Or some way else? What is the right way to deal with this problem?
Binary.JS seems to write a packet every time you write to the pipe, in my use cases.
Why not write the position changes to a buffer, and then use Underscore.js' throttling. You could call update() or whatever, which writes the whole buffer of changes all at once. You can call that function as often as you want, but use the throttled version so that it only actually runs at a maximum of every 50ms or so.
That delay is incredibly fast for web applications. Be sure you are considering the rate at which your clients can receive and ACK that info. Honestly, I wouldn't update the clients until the data has successfully been sent and ACKed. Otherwise, you will have way too high of an update rate for some.
A while ago I created a small cardgame web app for fun. The player plays against the computer and mostly it works fine. Sometimes though the computer player gets into a loop, the point of the game is to lose all your cards and if you don't have a card to play you take the pile. Sometimes the computer plays x,y,z, takes the pile, plays x,yz, takes the pile etc.
I keep track of the moves I've made, so at any point I have an array that looks something like : [C2,D5,H2,S4,C5,H2,S4,C5,H2,S4,C5]
In this case I can see that I've gotten into a loop of playing H2,S4,C5, then taking the pile and then repeating.
So, the generalized problem is, what's the best way to detect repeating patterns in a list? I could probably whip something up using a simple for loop, trying to find the card I'm about to play and if I find that in position x then I could check whether the pattern from x to n repeats at position x-(n-x) to x, but this seems like the kind of problem that could have a nice algorithm for it. How would you code this given the following function signature:
function findLoops(previousMoves, nextMove, maxPatternLength) {
//Return [loopLength, loopCount] or null if there are no loops
}
p.s. this is not a homework assignment, the game exists and is at http://www.idiot-cardgame.com if anyone is interested :)
First the general question: Your suggested method
trying to find the card I'm about to play and if I find that in position x then I could check whether the pattern from x to n repeats at position x-(n-x) to x,
looks really good. I would suggest basically the same. It is O(n) and needs a fixed amount of storage, and is simple: what else would you wish for?
Second: You can check for repetition in games generally if you keep a hash table of all previous game states (complete state, nothing left out). Everytime you reach a new state look up if it is in the hashtable, if its in it: you game state is looping.
In Javascript you have builtin hastables so this is very easy to do with something similar like this:
new_state = next_move(old_state);
new_encoded_state = encode(new_state); // make it into a string
if (allstates[new_encoded_state]) {
// we are looping!
} else {
allstates[new_encoded_state] = 1;
// no looping
}
The variable allstates is not an Array but of type Object. You can have array like access with strings and this uses the Object as hastable.