ScreenSpace canvas not working - user-interface

I am upgrading the UI of my program (from the old Unity UI system to the new one), but it seems like I cannot work with screen-space canvas (either camera or overlay canvases). Objects in world-space canvases work fine. With screen-space GameObjects show in my "Game" preview-screen in the editor, so I am a bit confused as to what the problem may be. To be clear: objects show in the "Game" screen, but not when I press the "play" button.
I attach a composite screenshot with information about one of the objects, the canvases and the camera.

I think I now understand what the problem is. Apparently screen-space canvases (either overlay or camera) can ONLY work with UI-specific game objects. I still do not know why other sorts of elements can be added as children of these canvases (and specially why they correctly show in the Game-preview screen!)
Even if I am missing something deeper here, using elements from the UI folder works where others don't. I thought perhaps someone could find that useful.

Related

Three.js transform controls not interactive (won't click or hover)

I'm playing about with three.js and webGL with an attempt to get html objects overlaid on a webGL model.
I intend to use three.js object loaders to render a 3D model, where I can then allow users to overlay HTML DOM objects in 3D space via a custom UI.
I've mainly been using the various different examples in the three.js docs (https://threejs.org/examples/ and https://codepen.io/AdamEDGE/pen/RRjEwz).
In order to allow the user to move the overlaid HTML objects via the UI, I've added the transform controls (https://threejs.org/examples/misc_controls_transform.html).
Things seemed to be going relatively well up to this point, but now I see that the controls are not hoverable or clickable to move the element.
I suspect I'm either missing code or an issue with the camera not aligning correctly, but I'm very new to this so I'm guessing.
I have also experimented with Jerome Etienne's blending tutorials, but on testing that caused other issues and I think may not be worth the trouble for what I'm going for (http://learningthreejs.com/blog/2013/04/30/closing-the-gap-between-html-and-webgl/index.html).
I have created an example that shows the problem (click on an object and the controls should show).
Its a simple webGL torus with two HTML images overlaid and mapped to a Mesh so I can link the controls to the HTML elements which are on a different scene.
https://jsfiddle.net/mattscotty/h5wuq86y/
control = new THREE.TransformControls(camera, glRenderer.domElement);
control.addEventListener('change', render);
The controls show on all the correct places when clicked as expected and I can use the keyboard to change the transform type (again see https://threejs.org/examples/misc_controls_transform.html for how it should work).
As I can't click or hover, I can't hook up to the relevant events.
I'm brand new to this and I'm quite sure I'm missing something obvious, so any help is appreciated.

SKSceneScaleModeResizeFill on ios8 scales improperly

I have written a game in SpriteKit using objective C and it works perfectly on ios9 but it looks hideous on ios8. I would really like to know how to fix this problem, either by “correcting” my mistake, or if I have no mistake then by finding a workaround for the bug in ios8.
I think I have really done all I can to make the problem as clear as possible, including making loads of screenshots to illustrate the problem and also making a new Xcode project that is as simple as possible while still showing the problem.
If you want to try the Xcode project, here is a link for it….
xcode project
If you want to see the screenshots of the problem, then here is a link for the screenshots.
Screenshots
Now I will try to explain the code I wrote and the problem illustrated in the screenshots.
PLEASE REMEMBER: My code works perfectly on iOS9.3. So my code is obviously not complete gargage. But admittedly, I am not an expert on handling screen rotation, so probably my code could be better.
I should probably mention that both scenes have scale mode set to SKSceneScaleModeResizeFill. I chose this mode because I had tremendous difficulty doing proper layouts for all possible screen sizes (including iPhone) when working with SKSceneScaleModeAspectFill. I do I hope I can solve this problem while sticking with SKSceneScaleModeResizeFill.
Anyway, my app is a SpriteKit game with two scenes. The main scene is the GameScene, where you play the game. And this scene has a pointer to the SettingsScene, where you can change the settings of the scene. (e.g. change the level of difficulty).
Anytime the user rotates the screen, GameViewController detects this change in viewWillTransitionToSize and tells the GameScene object about the new screen width and screen height. Game Scene then adjusts the positions of its sprites in consideration of the new screen orientation and then tells its SettingsScene object about the new screen width and height to that the Settings scene is properly laid out as well.
Please note that with this design, all sprites on BOTH scenes get repositioned any time the user rotates the screen REGARDLESS of which scene is actually active at that time..
As I said before, all works as expected on ios9.3. But on ios8, the result is attrocious. The screenshots illustrate one example of typical experience on ios8. If the user rotates the screen while using the game and then goes to the settings screen, he will see something awful. And will often be trapped in this terrible experience because the button for going back to the main game might not even be fitting on the screen anymore.
At first, it might seem like I am failing to reposition sprites for landscape mode in the settings scene. But this explanation is wrong. The text on the screen shows that the last layout was performed with the landscape orientation in mind.
So what is going wrong here?
Any suggestions would be highly highly highly highly appreciated.
Thanks!
-j
p.s. In case you don't want to look directly at the linked project file, here are some details about the example code. GameViewController implements viewTransitionToSize to handle any screen rotation. It directly tells the new screen dimensions to GameScene, which then tells SettingsScene. Both scenes rearrange their sprites in consideration of the new screen dimensions. And all goes well on ios9. On ios8, however, the inactive scene ends up looking hideaous when it is presented even though it clearly did reposition its sprites according to the new dimensions.
the problem is easily resolved by these lines....
gameScene.size = newScreenSize;
settingsScene.size = newScreenSize;
anytime the orientation changes.
This code is not required for ios9. The scene knows what size the screen is without assistance. But for ios8, it seems to be needed to add this code.

Microsoft Edge WebGL lose context

I m creating a THREE.js (latest version, r71) app, and sometimes I need to manually delete the 3D scene to display classic 2D content. So, what I do is clearing all variables like scene or renderer, and killing the WebGL context using renderer.forceContextLoss()
This method works fine on Firefox or Chrome, but it is not supported on Interner Explorer or Microsoft Edge, which cause multiple lags on my web page. I can't find a workaround to do this properly as I do in Firefox or Chrome.
If someone has a tip, feel free to tell me :)
Thanks
Try using two canvas tags and put one over the other as suggested here,
put them in a parent div tag then use the following css.
position:absolute;
left:0px;
top:0px;
EDIT:
In response to your comment, allow me to clarify my understanding.
You want to draw 2d and 3d.
You are resetting the webGL context.
You can't have 2 contexts to the same canvas simultaneously and I assume you want to use a a different context for your 2d content.
If this assumption is correct:
I am suggesting that you have 2 canvases and contexts simultaneously, one with your webGL context and 3d content, and another with the context you want to use for 2d content. Then you overlay these canvases by using absolute position, such that it looks like there is one canvas.
This means you never have to reload assets to switch contexts, just make sure you so the above canvas is transparent.
Also if you wrap the canvas in a div tag, it will not be at the top left of the page.
But If my assumption is wrong:
perhaps you don't want to use another context and just wish to clear the screen, in which case you should not call forceContextLoss()
If you wish to continue to use the webGL context, but clear the screen you should use clear()

Unity 4.6 - How to scale GUI elements to the right size for every resolution

The new Unity 4.6 comes with a new GUI, when I change de resolution on Unity the UI Button scales perfectly but when I test on the Nexus 7 device the Button looks too small. Any idea how to solve this?
Unity's new GUI system uses "anchors" to control how gui elements (like buttons) scale in relation to their parent container.
Unity has a tutorial video on how to use the new "Rect Transform" component (where the anchors are configured) here: http://unity3d.com/learn/tutorials/modules/beginner/ui/rect-transform.
The last half of the tutorial is all about anchors. That page has links to the entire tutorial series. It's not too long. You should watch the whole thing.
Specific to your question:
The anchors are visible in your first screen shot. They are those 4 little arrows at the top left of your button.
Right now, your button is only anchored by it's top left corner.
The two right anchors need to be dragged to the right so that the right edge of your button is anchored to a space inside its parent container.
Depending on your situation, the two bottom arrows may need to be dragged down so that the bottom edge of your button is anchored as well.
The video I linked above covers all this in detail.
Lastly, for the font size to scale nicely on different resolutions, you will need to add and configure a reference resolution component to the base canvas of your UI, as Ash-Bash32 wrote earlier.
Update: The best way to add a Reference Resolution component is through the inspector window for the base canvas in your UI.
1) click the "Add Component Button" at the bottom of the inspector.
2) type the word "Reference" in the search filter field.
3) select the "Reference Resolution" component in the search results.
The Reference Resolution is now renamed as Canvas Scaler.. Along with the renaming they have added many more features for the dynamicity of the Canvas. You can go through the Unity Doc of Canvas Scaler and also take a look at this article for a practical example of how and why to use Canvas Scaler. Also make sure you use the Anchor Points to good effect to make this more robust...
To Scale UI added the ReferenceResolution Component to the Canvas you want to scale.
P.S. Theres no Documention for ReferenceResolution
If you want the button to be the same size for all screens and resolutions, you have to add the canvas scaler component to the canvas and the set the screen match mode to: match width or height, here is the link to the docs, this helps a lot if you want to aim to different sizes or resolutions:
http://docs.unity3d.com/Manual/HOWTO-UIMultiResolution.html
This becomes giant and convoluted once you start laying things out in code AND using a canvas scaler, so I wish to provide a thorough answer to save someone the hours I went through.
First, don't use anchoredPosition to position anything, unless you fully realize it is a 0.0 to 1.0 number. Use the RectTransform localPosition to do the actual laying out, and remember it's in relation to the parent anchor. (I had to lay out a grid from the center)
Second, put a canvas scaler on the parent layout object AND the inner ui pieces. One makes the layout in the right position, the other will resize your elements so they actually show up right. You can't rely on the the parent unless the children also have scalers (and Graphic Raycasters to touch them).
Third, if you have a scaler, DON'T use Screen.width and height, instead assume the screen is the same value you put for the scalers (hopefully you used the same, or know what you're doing). The screen width always returns the actual device pixels, retina devices too, but the canvas scalers DO NOT account for this. This probably gives unity the one remaining way to find actual screen dpi if your game wants it. Edit: This paragraph applies to any parent canvas connected to the code doing your laying out. Not stray canvases, you can probably mix it up. Just remember unity's guidelines on performance with canvases.
Fourth, the canvas is still a bit buggy. Even with the above working, some things don't render until you delete and recreate a canvas, if you re-open the scene or it crashes. Otherwise, the above is the general "rules" I've found.
To center a "grid of things" you can't just use half of the canvas scaler's width or height, you have to calculate the height of your grid and set the offset by half of it, otherwise it will always be slightly off. I just added this as an extra tip. This calculation works for all orientations.

CALayer flickering when adding a foreground layer to IKImageBrowserView items with garbage collection on

I'm trying to implement a technique similar to the one in the ImageBrowserViewAppearance sample code from Apple (located here: http://developer.apple.com/library/mac/#samplecode/ImageBrowserViewAppearance/Introduction/Intro.html ), where CALayers are generated on top of the items in the IKImageBrowserView to customize the appearances of the objects in the image browser.
However, I'm getting a weird problem when I turn on garbage collection, and I can reproduce it in the Apple sample code. Simply turn on Garbage Collection in the target, and build and launch the ImageBrowserAppearance sample app. Then, add some photos to the image browser using the "Add Photos..." button.
Now, click on an empty portion of the IKImageBrowserView, and click and drag to start selecting multiple items in the browser view. As you drag the selection box around, you should notice that sometimes the pin and gloss overlay for some of the items flicker and briefly appear in the bottom-left corner of the IKImageBrowserView. All of the CALayers seem to do this occasionally, I've seen the white surrounding slide area flicker down into the bottom-left corner as well.
When I mimic the technique in my own code, I (not surprisingly) also can reproduce this badge flickering. However, this problem disappears when garbage collection is off.
Anybody have a clue what could be going wrong here? I'd like to use garbage collection in my app in conjunction with this technique, but the flickering is kind of annoying.
I bookmarked this a while back but Apple's changed the URL and the text. Fortunately I quoted it when I bookmarked it:
The Core Graphics APIs (Quartz 2D) see an approximately 25% reduction in drawing performance for applications compiled to use garbage collection.
That "25% reduction in drawing performance" text has been rewritten into a "slight overhead in code execution" and that was for 10.5. Perhaps Apple fixed it for 10.6. And you're talking Core Animation, not Core Graphics.
Still, Core Animation eventually has to talk to Core Graphics, and perhaps that performance issue hasn't gone away, and you're being bitten by it.
I fooled around with this a bit and can confirm I get the same behavior running the project with GC turned on. In fact, if you're patient enough and slowly change the selection one image at a time using the arrow keys, eventually it'll trigger the behavior and you can see the layers from one image in the view are displayed in the lower left corner instead of on top of the image. I haven't been able to find any sort of pattern as to when it happens, or any relation between which image is selected and which image has its layers missing. I'm assuming that for whatever reason, those layers are getting their frame origin set to {0, 0}, but heck if I know why.

Resources