I want to create a 360 degree turntable showing lots of pictures (12, 24 or 36) by controlling that rotation with touch events (like that example but coded for an iOS app natively).
The simplest idea depending on the touch position is to load that specific uiimage.
Any ideas what's the best practice for that? Is there a chance to create that image-turntable with the help of coreanimation faster? Any other hints on that? Any other projects known where I can get some help on that?
Thanks for your time and hints in the right direction.
Here's another example for an ipad-app from the "audi a8".
From the first example it becomes obvious that the objects have actually been photographed for each angle of rotation. This is the really tricky part. You will need a tripod and a camera with remote control, and if possible also a rotational platter to keep angles consistent.
Implementation is relatively straightforward. As you guessed, you just track the touch positions and, depending on delta to the last touch position, show the appropriate image.
well, you can just use the HTML/CSS/JS used in the same example... just load that in an UIWebView in your app and load your site embedded as a resource...
Subclass UIImageView, load array of your frames, handle tap movement over the screen y-axis and change active image accordingly. Don't forget to loop your images. :)
Related
I am working on a sample in which I have placed two textures one above the other. What I want, whenever user moves his finger on the screen, underneath view should get revealed as he moves. Wiping out front view to reveal underneath view is what I am looking for.
I would like to know some of ideas/ thoughts to implement this feature using OpenGL ES. Any related pointer will be highly appreciated.
Thanks in advance.
This does not sound performance-intensive so simple code can trump complicated tuned operations.
You don't need to use OpenGL. You can simply have two images - front and back - with the front supporting an alpha channel. Each time you get a hit or move, you clear a circular patch whereever the impact is for some certain radius or such.
And then queue-up a redraw. The redraw draws the two bitmaps, back first then front.
If possible, try to queue a redraw for just the the area where you have updated the front since the last draw.
I am trying to design another app and am struggling to think of the best way to do it. I'm after some advice please!
If you imaging a bicycle wheel in the middle of the ipad (and iPhone)... I want the user to be able to click on the tyre and spin it to the left or right. Depending on the speed of the swish will drive the speed of the wheel rotation.
It should rotate around the centre of the wheel and not move any other direction.
Do I need to use some graphics code, or simply listen for the touch, check the area they touched, then rotate the image around it's centre left or right?
Really I'm after some pointers around the methods to use - I'm not being lazy and asking for code, but if anyone knows of tutorials - that would help immensely!!
Thanks for any info.
Your best bet is to use one of the UIGestureRecognizer subclasses, probably UIPanGestureRecognizer as it includes velocity.
Apple's SimpleGestureRecognizers project will help you get started.
Is there a way to capture the amount of screen that is making contact with the users? I assume there is since this finger painting app shows the ipad responding to only the pixels that the user makes contact with.
Thanks so much in advance for your help!
The size of the touch is abstracted away by the framework, and UITouches only contain calculated (“best estimated”) points instead of the raw, actual areas that were touched. I would guess that the “pressure” was calculated from the duration and the direction of the touch.
In a nutshell, there is no public API to get the contact area.
I don't think Apple provides APIs for the size of the touch, or as #nickthedude said (I think) any kind of way to measure pressure. Basically, you need to implement your own algorithm/policy for determining line thickness/opacity/other effects. I believe a common way to do this is to measure the amount of time spent for the stroke, and work from there. For instance, if the user moved more quickly, you might want a thinner line segment. Apple really should just provide a canvas view of some kind. Best of luck!
to get the exact area you may have to roll your own but you can get uievents pretty easily and then do some magic from there. Basically impliment/override touchesBegan, touchesEnded, touchesMoved on the UIView in question and put in your custom code there.
Looking at the video maybe the amount of touches in the UIEvent set might correspond to the "pressure" of the touch, then again maybe not.
What if you laid down a series of successively smaller square uiviews wherever the user touched then if the touches "spilled" into the larger uiviews behind the smaller front ones than you could conjecture that the touch pressure was harder. Something to try I guess. Good luck.
Why not just describe what you want to do and foxus on asking about that instead - it may not have anything at all to do with the example that has you so otherwise enthralled - I can use a camera to monitor your hand from across the table and paint pixels on the screen via BT, completely ignoring any contact between your fingers and the screen.
What is the easiest and most practical way to implement smooth frame-based animation on the iPhone? I know that image sequences are easy to do, but if I have say 30 images flashing per second (30 fps) for 5 seconds, will it freeze up? Are there massive memory implications with this method?
I'm designing a game that will be mostly static, but there will be animations for some of the user actions. I'm hoping that OpenGL (etc.) won't be necessary.
I'd recommend looking at the Cocos2d-iPhone open source game engine.
Using an AtlasSprite it should be relatively straight forward to achieve the result you want.
This question needs to be more clear. Are you trying to display a sprite based animation? Or animate an image along a path? Or both?
If you have a series of images to animate, using UIImageView's animationImage is an easy way to go about it, although it is probably not efficient enough for a full scale game.
Is it possible to change just a portion of a Sprite's alpha in response to user interaction? A good example of what I mean is iFog or iSteam, where the user can wipe "steam" off the iPhone's screen. Swapping images out wouldn't be feasible due to the sheer number of possibilities where the user could touch and move...
For example, say you have a simple app that has a brick wall in the background that has graffiti on it, so there'd be two sprites, one of the brick wall, then one of the graffiti that has a higher z value than the brick wall. Then, based upon where the user touches (assuming their touch controls a sandblaster), some of the graffiti should be removed, but not all of it, which could be accomplished by changing the alpha value on a portion of the graffiti sprite. Is there any way to do this in cocos2d-iphone? Or, do I need to drop down into openGL, and if so, where would be a good place to start my search on how to accomplish this?
Ideally, I'd like to accomplish this on a cocos2d-iphone Sprite, but if it's not possible, where's the best place to start looking?
Thanks in advance,
Ben
The answer is here: http://www.cocos2d-iphone.org/forum/topic/7921#post-46394
But short answer: You have to override the draw method and resort to openGL methods.
I know this question is old, but it needs an answer anyway.