I want to lock user's ability to rotate view in all directions. I need model rotation only in left and right. How can i do this?
You can't use the .allowsCameraControl setting to achieve this restriction. You'll have to implement it yourself, as described in SCNCamera limit arcball rotation.
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Is there a way I can let the SceneKit's camera zoom but not rotate? And how can I delimitate the maximum and minimum zoom the user can do with the camera?
It depends what you mean by zoom – if you mean to do the same thing as 'zooming' a camera lens, you want to modify the yFov and xFov (field of view) attributes of the SCNCamera object. The camera stays in the exact same location, but changes its field of view like a zoom lens.
I cannot see how you can rotate the camera while zooming it – I’d need to see more context of where you’re using the camera. If you don’t touch the SCNNode the camera is attached to, you can’t possibly rotate it.
You're talking about user camera movement with allowsCameraControl, right? I don't think that's really meant to be the basis for a sophisticated user camera movement scheme, more of a simple debugging aid. If you really want fine control over how the user can move the camera, you're best served by creating your own camera node and moving it / changing its properties in response to whatever user input you want to handle (gesture recognizers, game controllers, etc).
I suppose you might be able to constrain the automatic user camera by implementing a scene renderer delegate willRenderScene method. You'd have to get the current pointOfView node, check its position and camera parameters, and change them if they're outside whatever bounds you want. But A) I'm not sure this would work, and B) it's probably not a great idea — it's sort of like messing with the internal view hierarchy of a system control class.
I'm working on an iPad application and that's my problem:
I elaborated an algorithm to know if a point is inside a polygon, in an image. So I need when touching the Image, to know the coordinates of the touched point and then do an action using those coordinates (an NSLog to make the example easy), the problem is that I can't use an IBAction on an UIImageView, and so can't recover the point's coordinates. Thanks for any help
I think at first you have to make polygon which fit to your image. And then you can use touchesBegan:withEvent: to get the coordinate of touch point and judge whether the point is inside of polygon or not.
Here is similar question like yours.
How to get particular touch Area?
I think this is a little difficult work, so maybe you would better use cocos2d library which have collision judgement function.
http://box2d.org/forum/viewtopic.php?f=9&t=7487
But also I think iOS is well constructed for handling touch, so this is beneficial effort for you.
I have been looking for the solution on the web for a long time. Most tutorials are fairly simple about adding shadow to a UIView. I also noticed that if we add a shadow to an UIImageView. The shadow shape could perfectly fit the shape of the content image if the image itself has alpha channel in it. Say for example, if the image is an animal with transparent background, the shadow shape is also the same as that animal (not a rectangle shadow as same as UIImageView frame).
But these are not enough. What I need to do is to add some changes to the shadow so it may have some rotation angle and compressed (squeezed or shift) effect so that looks like the sunlight comes from a certain spot.
To demonstrate what I need, I upload 2 images below, which I captured from the Google Map App created by Apple. You can imagine the Annotation Pin is an image which has the Pin shape, so the shadow is also "pin shaped", but it is not simply "offset" with a CGSize, you can see the top of the shadow is shifted right about 35 degrees and slightly squeezed the height.
When we tap and hold and pin, the shadow is also animated away from the pin, so I believe that such shadow can be made programmably.
The best shadow tutorial I can found so far is http://nachbaur.com/blog/fun-shadow-effects-using-custom-calayer-shadowpaths But unfortunately, that cannot make this effect.
If anyone know the answer or know any better words to search for, please let me know. Thank you.
(Please note that the shape of the image is dynamic in the App, so using any tool like Photoshop to pre-render the shadow is not an option.)
In order to create dynamic effects like this, you have to use Core Graphics. It's incredibly powerful once you know how to use it. Basically you need to set a skew transform on the context, set up a shadow and draw the image. You will probably have to use transparency layers as well.
It doesn't sound like you can use CALayer shadows, since that is meant to solve a specific use-case. The approach Apple takes with the pin marks on the map is to have two separate images that are created ahead of time (e.g. in Photoshop) and they position them within the map relative to a reference point.
If you really do need to do this at run-time, it should still be possible by using either Core Graphics or ImageKit. To get a blurred shadow appearance, you can use the kCICategoryBlur CIFilter. You can then convert the image to grayscale. And to get that compressed look you just need to resize and skew the image.
Once you have two separate images, you can either take the CGImageRef for the shadow image and can set that as the content of another sublayer, or you can add it as a separate view.
If you know what all the shapes are, you could just render a shadow image in Photoshop or something.
I want to create an omnidirectional scrollview that works pretty much like the one in the "Wall of Sound" app. As in, the user should be able to pull into any direction and never get to an end. I want to keep the move to be smooth (and not see the pages change as you would in a standard scrollview). Does anyone know how that can be done? Or would I need OpenGL for that?
Create a 3x3 grid of views, each the size of the viewport. As the scrollview moves into another section, rearrange the views to constantly put the viewport in the center. In most cases 3x3 is sufficient, but if redrawing the views is expensive, you may want to use a larger grid (5x5 for instance). This requires that you have some mechanism for splitting up your full view into tiles.
You can implement the same thing using CALayer if you like. If you go that way, you should consider instead using CATiledLayer. See Matt Long's quick introduction on CIMGF.
I'm taking my first steps through Unity, as a follow up to this question:
http://answers.unity3d.com/questions/56697/isometric-game-camera-limits
I now realized that I don't know how to make a collider actually collide. Now I have a GameObject I move around instead of the camera, and the camera is a child to that object. It has a box collider, and there're four other box colliders around the level so it will collide against them.. and it's not working, of course, because I was changing the position variable by hand. What do I do so this collides? use a rigidBody and apply forces to it? is there a way to put a maxVelocity on it? I can't see one, besides a rigidbody seems sort of overkill for what I'm trying to do. Otherwise I guess I just put mass 1, and export drag and force, but I'd much rather work with a maxSpeed, because drag will also affect the acceleration rate
I don't know if you have missed any steps but I can tell you what I've done if it helps any. Create a game object. Click on the object in the hierarchy and go to the top menu and component->physics->box collider.After you add the box collider you may have to adjust the size of the colliders as well. In addition make sure you character you are walking around with also has a collider.
You can take a programmatic approach. Do I get you right that you want to drag the cam around with the mouse or move it with keys? You can check the camera position by hand and apply boundings that way. It is quite easy to implement if your camera is locked into a single box.