How to detect a sknode hovers over another? - ios

I am making a game where I drag pieces over containers and if they match it can be placed if not, then returns to the bin, How can I detect if a sknode is hovering over the container, or how can I compare the 2 sprites? Thank you! any help would be great! :)

To see if they are hovering over one another, you could use the intersects function of CGRect using each nodes frame property (which is a CGRect). If the frames intersect, then they are overlapping to some extent.
To identify if the nodes are the same shape, then I’d restrict yourself to a specific range of shapes and have the nodes name property reflect what shape it is.
Edit: You could of course also use Sprite-kit's contact detection. Set it up correctly and you;ll only get notified when the correct shapes are placed over the correct containers.

Related

Interact with complex figure in iOS

I need to be able to interact with a representation of a cilinder that has many different parts in it. When the users taps over on of the small rectangles, I need to display a popover related to the specific piece (form).
The next image demonstrates a realistic 3d approach. But, I repeat, I need to solve the problem, the 3d is NOT required (would be really cool though). A representation that complies the functional needs will suffice.
The info about the parts to make the drawing comes from an API (size, position, etc)
I dont need it to be realistic really. The simplest aproximation would be to show a cilinder in a 2d representation, like a rectangle made out of interactable small rectangles.
So, as I mentioned, I think there are (as I see it) two opposite approaches: Realistic or Simplified
Is there a way to achieve a nice solution in the middle? What libraries, components, frameworks that I should look into?
My research has led me to SceneKit, but I still dont know if I will be able to interact with it. Interaction is a very important part as I need to display a popover when the user taps on any small rectangle over the cylinder.
Thanks
You don't need any special frameworks to achieve an interaction like this. This effect can be achieved with standard UIKit and UIView and a little trigonometry. You can actually draw exactly your example image using 2D math and drawing. My answer is not an exact formula but involves thinking about how the shapes are defined and break the problem down into manageable steps.
A cylinder can be defined by two offset circles representing the end pieces, connected at their radii. I will use an orthographic projection meaning the cylinder doesn't appear smaller as the depth extends into the background (but you could adapt to perspective if needed). You could draw this with CoreGraphics in a UIView drawRect.
A square slice represents an angle piece of the circle, offset by an amount smaller than the length of the cylinder, but in the same direction, as in the following diagram (sorry for imprecise drawing).
This square slice you are interested in is the area outlined in solid red, outside the radius of the first circle, and inside the radius of the imaginary second circle (which is just offset from the first circle by whatever length you want the slice).
To draw this area you simply need to draw a path of the outline of each arc and connect the endpoints.
To check if a touch is inside one of these square slices:
Check if the touch point is between angle a from the origin at a.
Check if the touch point is outside the radius of the inside circle.
Check if the touch point is inside the radius of the outside circle. (Note what this means if the circles are more than a radius apart.)
To find a point to display the popover you could average the end points on the slice or find the middle angle between the two edges and offset by half the distance.
Theoretically, doing this in Scene Kit with either SpriteKit or UIKit Popovers is ideal.
However Scene Kit (and Sprite Kit) seem to be in a state of flux wherein nobody from Apple is communicating with users about the raft of issues folks are currently having with both. From relatively stable and performant Sprite Kit in iOS 8.4 to a lot of lost performance in iOS 9 seems common. Scene Kit simply doesn't seem finished, and the documentation and community are both nearly non-existent as a result.
That being said... the theory is this:
Material IDs are what's used in traditional 3D apps to define areas of an object that have different materials. Somehow these Material IDs are called "elements" in SceneKit. I haven't been able to find much more about this.
It should be possible to detect the "element" that's underneath a touch on an object, and respond accordingly. You should even be able to change the state/nature of the material on that element to indicate it's the currently selected.
When wanting a smooth, well rounded cylinder as per your example, start with a cylinder that's made of only enough segments to describe/define the material IDs you need for your "rectangular" sections to be touched.
Later you can add a smoothing operation to the cylinder to make it round, and all the extra smoothing geometry in each quadrant of unique material ID should be responsive, regardless of how you add this extra detail to smooth the presentation of the cylinder.
Idea for the "Simplified" version:
if this representation is okey, you can use a UICollectionView.
Each cell can have a defined size thanks to
collectionView:layout:sizeForItemAtIndexPath:
Then each cell of the collection could be a small rectangle representing a
touchable part of the cylinder.
and using
collectionView:(UICollectionView *)collectionView
didSelectItemAtIndexPath:(NSIndexPath *)indexPath
To get the touch.
This will help you to display the popover at the right place:
CGRect rect = [collectionView layoutAttributesForItemAtIndexPath:indexPath].frame;
Finally, you can choose the appropriate popover (if the app has to work on iPhone) here:
https://www.cocoacontrols.com/search?q=popover
Not perfect, but i think this is efficient!
Yes, SceneKit.
When user perform a touch event, that mean you knew the 2D coordinate on screen, so your only decision is to popover a view or not, even a 3D model is not exist.
First, we can logically split the requirement into two pieces, determine the touching segment, showing right "color" in each segment.
I think the use of 3D model is to determine which piece of data to show in your case if I don't get you wrong. In that case, the SCNView's hit test method will do most of work for you. What you should do is to perform a hit test, take out the hit node and the hit's local 3D coordinate of this node, you can then calculate which segment is hit by this touch and do the decision.
Now how to draw the surface of the cylinder would be the only left question, right? There are various ways to do, for example simply paint each image you need and programmatically and attach it to the cylinder's material or have your image files on disk and use as material for the cylinder ...
I think the problem would be basically solved.

How to detect intersecting nodes of children of other SKSpriteNodes

I hope you all can help with this. I'm working on app of a board game. I have hex shaped tiles which are called randomly and laid out at the start of the game. Each of these tiles has four sides with a value of 1 and the other two sides have values of 2 and 3.
Each tile is a SKSpriteNode with transparent rectangle Nodes on the edges. There are 5 different types of tiles and they need to be separate Sprites with child nodes because in addition to being randomly laid out they area also randomly rotated. So I need to know programmatically which tile edges are touching which edges of other tiles.
Like this:
https://app.box.com/s/nnym97st3xmrsx979zchowdq1qwsmpoo
(I tried to post an image of what I'm trying to accomplish, but apparently I don't have a high enough of a rating.) ;-)
For example: If a "2" is touching a "3", etc.
I first tried Collision detection, but of course that only works with dynamic, moving objects.
I tried an IF statement to compare if the other nodes were touching and then remembered that the coordinates where specific to the Parent Node, so that didn't work.
I then tried intersectsNode, but that seems to only work with nodes under the same parent.
I am currently working with convertPoint in order to get the coordinates to match the scene and thus be comparable. But I can't seem to get it work the way I need.
There must be something simple that I am not seeing. Any ideas?
Certainly not simple.
One solution would be to start all your shapes slightly spaced out from each other. Add invisible child nodes with physics bodies to all six sides and give each physics body an appropriate category based on their rating (1, 2 or 3).
When you start the game, move all the outer nodes into their proper position (sides touching) by using whatever movement method your prefer. This will give you contact messages as each hex side touches another. The contact messages will tell you what side number is touching its neighbor.
The exact coding of this idea depends on your current code, game play, etc...

Hit-testing a UIGestureRecogniser in 3d space

I'm reasonably new to iOS's SceneKit and have come across a dilemma with regards to user-interaction in a 3d scene:
I have a set of SCNNode cubes in an SCNView, and would like to be able to pin-point where a user touches the mesh of a given cube, as a 3d coordinate (so as to later manipulate the scene according to touch vectors). At present, I've been using a UIGestureRecognizer in order to achieve basic hit-testing, but this seems to be limited to returning 2d-points.
This isn't a problem when wanting to hit-test a whole node itself, as this can be achieved via a UIGestureRecognizer's hittest method in the SCNView. However, does anybody have any suggestions as to how to precisely locate where a touch landed on a node, in terms of coordinates (i.e. SCNVector3)?
Thanks!
You are on the right track with calling hitTest:options: on the SCNView. As you have probably seen it results in an array of SCNHitTestResults.
The hit test result can tell you many things about the hit, one of them being what node was hit. What you are looking for is either the localCoordinates or the worldCoordinates.
The local coordinate is relative to the node that was hit. Since you are asking "how to precisely locate where a touch landed on a node" this is probably the one you are looking for.
The world coordinate is relative to the root node.

iOS: Segmented touchmap over image

I've been trying to find a way to solve this problem, and haven't been able to find anything useful, so forgive me if this is a duplicate of something I couldn't find.
I have, essentially, a large complicated image in the style of a stained glass window in a scroll view so that I can pan and zoom around it. Each of the individual segments of the window has some information associated with it. What I need to be able to do is tap on any of the segments and determine which segment was tapped so that I can display the information. What I'm not sure of is how to do the mapping between touch points and segments. Most of the segments aren't even regular polygon shapes let alone orthogonal squares, so I can't think of a straightforward way to determine which segment I've tapped.
If anybody has any ideas as to how I might go about implementing this, it would be most appreciated!
Cheers
Put each individual segment in a different layer. Now you can do hit-testing on what layer was tapped. Your test must be designed so that if a layer was tapped but on a transparent area (i.e. outside its segment), your test will fall through to the next layer behind it. Thus the test will succeed if and when you discover a layer's non-transparent region under the tap. Since it is one segment per layer, the segment is the one corresponding to that layer.

How to drag and drop multiple SpriteKit Nodes with the same parent?

I have multiple SKSpriteNodes(some rectangles) which are draggable (I followed the tutorial on Sprite Kit Tutorial: How To Drag and Drop Sprites). When a collision happens between them, I group them (by making the one rectangle a parent and the other a child). No matter how many rectangles I will combine, I manage always to have one parent and multiple rectangles that belong to it. I am doing this cause I want to move cubes belonging in a group together and I observed that if I move the parent, I move all of its children. What I am doing to achieve this is to transform the group at touchBegin and to make the touchedNode a parent and all the other nodes of the group children of this new parent. I believe that the following image may make things a little bit more clear.
The problem I am facing is that I can drag the group even if I touch at the white space (shown with red circle) included between the horizontal and vertical rectangles. As all rectangles shown in the image have the same parent, I guess that there is a bounding box that include them all and this is why the white space in the middle can trigger a drag event.
Does anyone have any idea how I can deal with this issue?
Is it possible to have a bounding box as shown in the following image?
Thanks in advance.
You need to write custom hit testing to perform this kind of trick.
For every click -> For every box (within certain range of touch) -> For every other box (within certain range of touch) -> Combine the two box frames into one (CGRectUnion(<#CGRect r1#>, <#CGRect r2#>)) and see if your finger is within the rect.
This might give results for a lot of dispersed rectangles, so limit your initial search of boxes to a given range from the touch itself.
Apart from that it's just simple code.

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