I need help implementing controls to move a SceneKit sphere. I want to have the user touch on the screen and when they move their finger around, the ball will move relative to the position of the user's finger. I don't want the y to increase or decrease I just want x and z, almost like a hula hoop.
I think you can use the GameController Framework seen Apple have released the WWDC Demo 'Fox', and it use GameController to control the character.
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I’m starting a learning project. The idea is that you have an archer character that is static, that has a bow attached to it that shoots arrows to targets of varying difficulty.
Turns out that right at the start I’m stuck. How do I make it so that the bow rotates when the player clicks and holds the mouse anywhere on the screen? So I click+hold and move left/right and the bow rotates left/right to aim the shot. I’d like to also eventually make it portable to phones (so you’d tap+hold etc).
Stack Overflow isnt a code writing service but i will explain what you must do:
Method 1 (Exact Aiming):
For every frame the mouse is down:
Make a Ray from a screen point... hint (use
camera.ScreenPointToRay).
Get a far point along the Ray using ray.GetPoint(distance);.
Bow.Transform.LookAt(newPoint, Vector3.Up);.
Method 2 (Continuous Movement):
Make a variable oldMousePos to store a Vector2 location.
Record your initial screen click position into that variable on a
mouse down event.
Have a function that runs once every frame the mouse stays down.
For the direction of the rotation of the bow, you can use
(newMousePos - oldMousePos).normalized;.
For the speed of rotation for your bow, you can use (newMousePos -
oldMousePos).sqrMagnitude;.
I am working on a tabletop game that user controls using accelerometer in the phone. It is pretty similar to Labyrinth on iOS.
The scene contains a tabletop created using planes and cubes, and a sphere as a ball. As it works in Labyrinth game, on tilting phone ball should drop to the tilted side, while the camera stays centered to table. I am trying to do similar thing where user tilts the phone, and objects on table move to tilted side.
Currently, I add the x and z component to Physics.gravity on tilt. Sadly, this change in gravity does not affect the ball which stays put on the table. Use gravity is selected for the ball, and it drop down from height to the tabletop initially and then comes to halt. After the initial drop, ball does not react to any gravity change.
I have also tried rotating the whole table, but using transform.rotate does not work either. The table rotates perfectly, alongwith the camera, but the ball stays put hanging in the air. So, currently I am out of my depth about the issue.
Is there any other way to allow tilt action registered, so that ball moves to the tilted direction? I cannot use addforce function, as there are multiple objects which need to react to tilt, and it will be difficult to keep track of that many addforce calls. How else can I get it working?
See this post for some related information.
As for why your sphere is sticking to the table, can I assume your sphere has a rigidbody? If so, you need need to wake it up:
if (rigidbody.IsSleeping())rigidbody.WakeUp();
Ideally you would make that call only after detecting a change in orientation/gravity, not every frame.
I have a simple project built with Cocos2D and Chipmunk. So far it's just a Ball (body, shape & sprite) bouncing on the Ground (a static line segment at the bottom of the screen).
I implemented the ccTouchesBegan/Moved/Ended methods to drag the ball around.
I've tried both:
cpBodySlew(ballBody, touchPoint, 1.0/60.0f);
and
ballBody->p = cgPointMake(touchPoint.x,touchPoint.y);
and while the Ball does follow my dragging, it's still being affected by gravity and it tries to go down (which causes velocity problems and others).
Does anyone know of the preferred way to Drag an active Body while the physics simulation is going on?
Do I need somehow to stop the simulation and turn it back on afterwards?
Thanks!
Temporarily remove the body from the space.
If you want the object to have inertia when you release it, that's a different story. The cleanest way is to attach a fairly stiff spring between the ball and a temporary sensor body that moves under the control of your finger. When you let go with your finger, the ball will retain whatever kinematics it had while you were dragging it. Be sure not to remove the ball from the space in this case.
You aren't updating the velocity of the object when you aren't using cpBodySlew(). That is why it falls straight down.
A better way to do it is to use a force clamped pivot joint like the official demos do to implement mouse control. http://code.google.com/p/chipmunk-physics/source/browse/trunk/Demo/ChipmunkDemo.c#296
I'm making an iPhone game in cocos2d.
I was wondering how I would make the camera / the view follow a specific sprite?
would I use the CCCamera class?
Yes, CCCamera would work. However, it has some drawbacks that make it undesirable for some uses. Moving the layers respectively all other objects relative to that sprite may be a better solution. It depends on the game.
First, read up what the different approaches and their drawbacks are, you can get a lot out of this cocos2d forum thread:
http://www.cocos2d-iphone.org/forum/topic/5363
It would be helpful if you could describe what your game is about and why you need the camera attached to that sprite.
For example, if you're thinking of a running game like Canabalt, i would not use the camera to scroll over the world, but instead scroll everything relative to the player (towards him) with the player sticking at about the same x coordinate while running. Perfect examples of games where you would not move the camera at all are the iCopter games, they are basically simplified versions of Canabalt. Notice that the player sprite always stays at the exact same x coordinate, and the game world just scrolls
Scrolling the camera itself in my opinion makes the most sense if you have a large game world that the player can traverse in all directions, and the number of objects are simply too numerous and also moving about in various directions, so updating their positions individually each frame would be both overkill and prone to errors. And since the game world is so huge, you would want to use the camera's position to limit what is drawn on screen.
use CCFollow actions
Like these :-
[self runAction:[CCFollow actionWithTarget:(u r hero) worldBoundary:CGRectMake(0,0,1050,350)]];
it will helps
I am making an app in which balls roll on tracks.
So when we touch and drag the balls around the screen, they should move along the tracks. If the drag goes out too distant from the track, it should stop. The tracks can be any shape.
What is the best appraoch..?
It depends on how the track is defined programatically, but it you've got a CGPath that represents it, or can make one, use can use CGPathContainsPoint in the touchesMoved method and refuse to update the position of the ball if it is outside the path.