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.
Although I am quite experienced with most frameworks in iOS, I have no clue when it comes to 3D modelling. I even worked with SpriteKit, but never with something like SceneKit.
Now a customer wants a very ambitious menu involving a 3D object, an 'icosahedron' to be exact. I want it to look something like this:
So I just want to draw the lines, and grey out the 'see-through' lines on the back. Eventually I want the user to be able to freely rotate the object in 3D.
I already found this question with an example project attached, but this just draws a simple cube: Stroke Width with a SceneKit line primitive type
I have no clue how to approach a more complex shape.
Any help in the right direction would be appreciated! I don't even need to use SceneKit, but it seemed like the best approach to me. Any other suggestions are welcome.
to build an icosahedron you can use SCNSphere and set its geodesic property to YES.
Using shader modifiers to draw the wireframe (as described in Stroke Width with a SceneKit line primitive type) is a good idea.
But in your case lines are not always plain or dotted — it depends on the orientation of the icosahedron. To solve that you can rely on gl_FrontFacing to determine whether the edge belongs to a front-facing or back-facing triangle.
i have a 2d object, something like a square grid. I would like to add some depth to it so it looks like its going off into the distance so the top left and right points of the square should get closer together, something like looking down a long road. I currently have the square make on a 2d surface and it looks fine i was just wondering if theres a method in Cocos2d that will rotate the square and give that effect. I've tried using
CCFiniteTimeAction* action = [CCActionTween actionWithDuration:7 key:#"scaleY" from:.5 to:1.2];
[self runAction:action];
but that only seems to decrease the length and width of the square and not actually adds any depth to it. I found CCTransitionFlipY which seems like it would give a desired effect but it looks like that is only for Scenes. Any help into this would be awesome!
Found a nice solution here. I used CCOrbitCamera to get the desired effect!
I'm currently making a game where driving a moon lander across the terrain of alien planets. The lander is free moving so you can turn any direction you like.
I've got a camera centred on the player's vehicle and navigation is working well, however...
As the player approaches the horisontal sides (x) of the map I'd like the map to display continuously.
I've used a couple of different approaches so far; I've added an identical sprite as the map to the left of the map and created a method that moves the extended map to the right side if you approach that side instead, and I've also tested with two different extended maps, one for left and one for right. I've then setup physics for the extended maps and changed the landers position from one side of the map to the other as it collides with the extended maps.
My issue is that I'd like to have my enemies spawning and walking around the main map and as you approach the side you will of course not see the enemies on the other side of the map - you'd only see the extended map with no contents.
My preference would be for the world to "bend" so that as you approach the left edge you'd automatically see the right edge and vice versa. I have no idea whether this is even feasible so any suggestions are much appreciated.
Thanks in advance.
I'm not sure I understand your question. Maybe this will further discussion, anyhow.
If you are looking for a scrolling behavior then I would have two backgrounds (or more if you want a wider scrolling field) and your method for swapping the tiles around to make the background feel continuous, use the "camera" tracking technique and shown in Apple's sprite kit demo to follow your player (which it sounds like you are doing). Then when aliens move offscreen in either direction relocate them in the same way that you would swap out your background tile(s) with something like position.x += widthOfBackgroundTile.
I am looking into making an iOS app that has little creatures. I plan on having these creatures grow and change shapes based on user interaction. So the creatures could end up looking very different based off what the user does.
My problem is animating these creatures. I have dealt with simple animations in the past with cocos2d, but nothing like this.
How can I animate these creatures being different sizes and shapes without having my graphic designer draw every possible image that could be used. In the game spore a user can create an animal of whatever shape or size they want and these animals animate. My question is how can I do something similar in 2d? I know this can't be a simple answer, but a point in the right direction is all I am looking for.
You could use some CGAffineTransforms to scale your drawing and custom filters with Core Image maybe to change the color.