I have a sprite which i animate using CCAnimate. the animation is composed of 4 spritesheets that i swap when needed. everything works pretty good except for some flickering when swapping spritesheets.
any ideas on what to do?
i've found a solution in case anyone is interested.
it seems theres a lag when switching between CCAnimation objects, that make the frame be blank for a split second. the solution is to manually set the sprite to the first frame of the coming animation immediately after ditching the old one.
more info here:
http://www.cocos2d-iphone.org/forum/topic/8729
Do you preload the spritesheets using CCTextureCache's addImage? If not, you'll notice a lag whenever you switch to a spritesheet for the first time.
Also, unless your spritesheets are so big that you can't fit all animations into a 1024x1024 texture you should simply put all of the sprites into one sheet, instead of using multiple like for example four 256x256 spritesheets. You hardly gain anything from doing that, at worst you lose the benefit of spritesheets because as soon as you render from two different spritesheets it'll be two draw calls instead of one. Texture atlases are not for organizing your animations but to keep as much as possible of all of your graphics into as few as possible textures.
Related
This issue has been encountered by someone else, but I've not seen any solutions - see ( http://openradar.appspot.com/6941930 ).
I have a UIScrollView whose content view's layer contains two CATiledLayers. One tiled layer draws content quite fast (but long enough to make drawInRect: too slow!), the other draws them slowly.
The quicker CATiledLayer doesn't Zoom has has default LOD settings, with a large tile size.
The slower CATiledLayer is zoomable.
Using just one of the CATiledLayers behaves as expected.
The problem is adding both layers to the visible screen causes one or the other to behave slowly. Annoyingly, it seems to make the content that draws normally fast, much slower.
I've not seen a way yet to reliably know when one CATiledLayer has completed its draw.
I think the solution would be to queue the Tiled Layers, so draw the slower tiled layer when the quicker one has finished. But the documentation on CATiledLayer is pretty bad.
I've tried to use a NSTimer, and set it for a 3 second wait before drawing the 2nd Tiled Layer. This however does not seem to solve the problem! I'm lost!
CATiledLayer seems to favor any tiles near the center of the screen. Perhaps one of your layer's is closer to an edge?
Guys. I'm writing a scrolling shooter game that has a very large Background image chopped up into smaller images to make it more manageable. Right now it is setup so when the GameNode is init'd. A big long list of Images are added to the ParallaxNode and it is added to the Game.
I thought I might save a lot of memory if I only kept one or two loaded into memory and swap them out as the Hero Character moves through the level. The problem is I can't seem to create a parallax background in another method that's called later. No errors it just doesn't show and seems to be the same code. Any Ideas?
Well I created the parallax layer having four layers in it and added it to the level layer which is extending from GameNode.
If you can post some code, that may help.
I have a problem when try to load the big animation with about 54 images (320x480 each image) into CCSpriteFrameCache, I can't use plist for this. How can I make the animation work? At this time, my animation can't work on iPhone 2G, 3G, and iPod.
Thank for your help,
John
You won´t be able to do it...
Consider playing a video or just animating an small portion of the screen.
Your best bet is to determine why the animation has 54 images that are all the width/height of the screen. This is an unnecessary number of images.
Break the animation down:
Is the background 'static' (does it move around, change constantly, etc?)
If it moves around a bit, but is really part of a much larger "canvas" then simply export out the entire background canvas and perform the movements yourself using the Cocos2D Actions available to you (CCMoveTo, CCJumpTo, CCDelayTime, CCSequence, etc)
What in the animation moves around, and how does it move around?
Can it be broken into much smaller bits and the frames for the various "characters"
or "movable objects" within the scene be exported out onto a sprite sheet (saved out
via Zwoptex?)
A good animation sequence should be a series of much smaller images, all working together in unison to create the final "animation sequence".
If you break it down, I wouldn't be surprised if you were able to reduce your 54 images at 320x480 each down to a handful of 512x512 spritesheets (ala Zwoptex).
If your having trouble breaking it down, I would be available to look at the final animation and help you determine what could be minimized to reduce the overhead.
I am trying to implement the style of 3D rotational animation you see in the Elements and the Wired iPad applications. The animation has the UIScrollView style acceleration so it looks like they have connected a UIScrollView to a sequence of images.
I have tried implementing it in UIKit, using an "empty" UIScrollView to increment through an array of images and set the contents of a UIImageView, based on the content offset. This works but even with scaled down images on the simulator, it is very sluggish. I am not sure how I could optimise it to make it run faster.
Source Code on GitHub
I have also tried doing something similar in Cocos2D. Cocos could animate the sequence very smoothly but I couldn't control the animation. I tried using a scroll view and setDisplayFrame to step through an animation but it didn't work.
Any help or suggestions on either option would be greatly appreciated.
I'm not 100% sure I understand the effect you're trying to achieve, but if you're referring to the images in "The Elements" app which you can spin around, then yeah, you probably don't want to be doing that with an UIScrollView.
You can control the animation of content in Cocos2d. While you can set an animation to "just run", you can also manually set frames directly out of an animation, so if you can get smooth animation out of Cocos, you should be able to do it interactively. Look at the atlas sprite object - you can set the rect of an animation frame directly.
However, again, I'm not sure this is the best approach, either, since that's a lot of frames for a texture. If you're going to be doing a lot of 3D photographic objects, you might consider looking into the video codecs and scrubbing along a video instead of trying to pack all the frames of a rotation animation into a series of textures.
Just so you know, the guy who made "The Elements" wrote an article about the development of the app, and here's what he had to say about the 3D rotatable objects:
"Creating fluidly spinning objects with the level of crystal clear photographic quality I demanded is actually harder than it might seem. A number of the obvious things the more technical of you might think of turn out not to work for reasons too complicated to get into here. Suffice to say that John designed a brilliant solution that uses the iPad's excellent graphics subsystem to lend a hand in ways it's not normally intended to."
I don't know how exactly they achieved the 3D objects, but perhaps that "uses the iPad's excellent graphics subsystem" mention gives you a clue where to head from here...
I need to draw the background for a 2D space scrolling shooter. I need to implement 3 layers of stars: one distant nebula (moving really slow) in the background, one layer of far away stars (moving slow) and one layer of close stars (moving normal) on top of the other two.
The way i first tried this was using 3 textures of 320 x 480 that were transparent pngs of the stars. I used GL_BLEND and SRC_ALPHA, ONE_MINUS_SRC_ALPHA.
The results were not great even on the 3GS. On the first generation devices the FPS dropped to 40..50 so i think i'm doing this the wrong way.
When i disable the GL_BLEND everything works great even on the 1st gen devices and the FPS is back to 60 again... so it's must be the fact that i'm trying to belnd large transparent textures.
The problem is i don't know how to do it some other way...
Should i draw only the first nebula like an opaque texture and then try to emulate the middle and top star layer with small points moving around the screen?
Is there any other approach on the blending issue? How can i speed up the rendering process? Is one big texture (tileset) the answer?
Please help me cuz i'm stuck here and i can't get out.
I don't know how you want your stars to look like, but you might want to try to move them from a texture to geometry by using GL_POINTS in the DrawElements or DrawArrays maybe just replace the top two layers with layers of geometry. You can manipulate the points using PointSize, PointSizePointerOES and PointParameter to modify the rendering of the points.
You might want to use multi-texturing to see if that speeds it up. Each multi-texture stage can be assigned a unique transformation matrix, so you should be able to translate each layer at different speeds.
I believe all iPhone models support two texture stages, so you should be able to combine two of your layers into a single draw call. You might still need to resort to blending for the third layer.
Also note that alpha testing could be faster than alpha blending.
Good luck!
The back nebula should definitely be opaque; everything else is getting drawn on top of it, and I assume the only thing behind it is black. Also, prideout has a point: assuming your star layers can have effectively 1-bit alpha, that's definitely something you can try. Failing that, the GL_POINTS technique Harald mentions would work as well.