I'm trying to make that effect, but I don't know how or the name
Of the effect?
That's not "an effect" but could be accomplished a few different ways. If it were me I'd look into Core Image filters (CIFIlters). If you've never used them, start with this Apple example:
https://developer.apple.com/library/prerelease/ios/samplecode/CIFunHouse/Introduction/Intro.html
Then look into changing the size and position of the type, applying pixellation and maybe a bit of blur.
Related
I am interested in to how change hue of the texture in efficient way ? I am experimenting to create space dust which will change it's color every few seconds with nice, smooth transition from one color to another.
I find this possible in few ways:
Using core image like in this example. But I don't know how will this work in combination with Spritekit...
Using particle emitters to create space dust and change color of particles over time using particleColorSequnece property.
And easy one that came up on my mind , while playing with Photoshop, which is using two same, but differently colored images, one over another, and changing the opacity of the topmost one.
This gives me the effect I want, and actually looks fabulous, but is there any better way ? Maybe using SKTexture? In this particular case, I just need to change from one color to another , but what would be an efficient way to do this when multiple changes are required one after another ? This way, my third example requires additional images...
Here is the link which most closely describe what I am trying to accomplish. Just look how space dust changes its color overtime(from dark blue to purple and later to green or orange). I suppose this is done programatically... I would like to ask moderators to remove a link if it is not suitable to post it here. Thanks!
It is kind of a hard questions to answer and is rather subjective, however...
I personally would do the Emitter Node approach, because it seems like it is built for the type of use you are looking for and could have some cool effects trailing behind.
With that being said you specifically asked about changing the hue and colorBlendFactor might be what you are really looking for. I don't have a great link for it, but this might get you pointed in the right direction. You can see how they are blending colors to get the desired result.
Your solution with changing the alpha of two separate colors doesn't sound like a bad approach either.
Hopefully that helps and good luck =)
A little background: I'm working on an iOS app that has a variety of status icons for various states. These icons are used in a variety of places and sizes including as UITableViewCell imageViews, as custom MKMapAnnotations and a few other spots. I actually have a couple sets which include a more static status icon as well as ones that have dynamic text injected into the design.
So at first I went the conventional route of using static raster assets, but because the sizes were dynamic this wasn't always the best solution and I wasn't thrilled with the quality of the scaling using CGAffineTransforms. So instead I changed gears a bit and tried something else:
Created a custom UIView subclass for each high level class of icon. It takes as input the model object that derives the status from (I suppose I could have also just used an enum and loaded this into some kind of model constructor but this is how I did it) so it can decide what it needs to draw, then does the necessary drawing in drawRect. Since all of the drawing is based on the view bounds it scales to any reasonable dimensions.
Created a Category which has class method constructors that take the model inputs as well as the size you want to use and constructs the custom views.
Since I also wanted the option to have rasterized versions of these icons to plug into certain places (such as a UITableViewCell imageView) I also created constructors that build the view and return a UIImage using the fast iOS7 snapshotting functions.
So what does this give me? Well here's the pros/cons that I can see.
Pros
Completely scalable graphics that can easily be used in a variety of different scenarios and contexts.
Easy compatibility with adding dynamic info to the graphics such as text. Because I have the exact shape data on everything I'm drawing I don't need to guesstimate on the bounds for a text box since I know how everything is laid out.
Compatibility with situations where I might want a rasterized asset but I still get all the advantages of the dynamic view since I'm not rasterizing it till I need it.
Reduces the size of the application since I don't need to include raster assets.
Cons
The workflow for creating the draw code in the first place isn't ideal. For simple stuff I can do it straight in code but for more complex things I'll need to create the vector asset in Illustrator or Sketch then bring it into PaintCode and clean up the generated draw code into something more streamlined. This is not the most ideal process.
So the question is: does anyone have any better suggestions for how to deal with this sort of situation? I haven't found an enormous amount of material on techniques for this sort of thing and I'm wondering if I'm missing a better way of handling this or if there are any hidden gotchas here...performance doesn't seem to be an issue from my testing with my approach but I haven't tested it on the iPad3 or iPhone 4 yet so there could still be some unknowns.
You could try SVGKit, which draws SVG files, and can export to a UIImage, if desired.
Here is an example of what I would like to achieve.
Is there a way to "transform" a label in Cocos2d and obtain a curved text? I do not find any property in the CCLabelBMFont class that seem to allow this.
Any suggestion wellcome.
Rason for asking: I would prefer not to use pre-generated (with Photoshop or GIMP) text images. Hence I am looking for an answer to this problem and not to an alternative method.
One of the moderators of the Cocos2D forum has replied to me in their forum and it doesn't seem possible. Here is the link to the discussion on the forum, but as far as I can tell there is no solution (In my opinion it would require having implemented a draw call in the labels that blends the pixtures according to the new image matrix resulting from bending the original label image and as far as I can understand CCLabelBMFont does not seem to support this - and I am not sure that is easily possible to do so as the class does not derive from CCSprite but it may be in some other way that I do not know at the moment).
What I basically need to achieve is a Fruit Ninja - style "slash" effect, where the "slash" trails the user's touch and follows the shape of the user's gesture, and is thinner the longer the distance the user has swiped.
The simplest way to achieve this seemed to be to collect all the points the user passes through in a UIBezierPath, and "stretch" an image through the length of the BezierPath. This would achieve the kind of "trailing" effect I was looking for and also ensure that the line is thinner if the distance travelled is longer.
However I can't seem to find a way to actually implement this. Is this even possible?
Alternatives? Thanks.
P.S: This is for a low-medium priority section of a regular app and not a game, so I would like to avoid having go down to OpenGL and spend a lot of time to achieve this (with completely custom drawing, etc). Something at the SDK level would be preferred, and if that's not possible at all, we'll just figure out a different UI.
Thanks!
For pretty easy-to-use stretching teqhniques of images/views you could look into
https://github.com/hfossli/AGGeometryKit/
I recommend trying to draw using CoreGraphics. See this link
http://www.effectiveui.com/blog/2011/12/02/how-to-build-a-simple-painting-app-for-ios/
Okay. Maybe you can use this.
https://github.com/hfossli/AGDraw
Just something I wrote a while ago. Hit clear and try to draw something (clear will toggle between two types of strokes). You'll see the width of the penstroke will increase with the velocity you use.. I guess that fits your need. If you fix some bugs, please make a pull request. You are free to use the code, but I will add a MIT license later.
I've a problem. I need to apply a filter like Pixelate or Blur to an entire UIView.
Like the eBay iPad app.
I thought to use GPUImage but I don't know how to do it.
There is a way to apply a filter to a GPUImageView directly without pass a UIImage?
The primary problem is that making a screenshot of a large UIView on an iPad 3rd is to expensive (2 seconds for the UIWindow grab). So the perfect solution is to apply filter directly to the views, just like eBay app, but.. how?
Thanks to all!
To pull a view into GPUImage, you can use a GPUImageUIElement source, which takes a UIView or CALayer as input. There's an example of this in the FilterShowcase sample application.
This does rely on the -renderInContext: method of an underlying CALayer, which can be expensive for redrawing the view. However, if the view is static, you just need to use this update once and the resulting image will be cached on the GPU as a texture. Filter actions applied to it after that point will be very fast.
You might be able to achieve the look you are after by applying CIFilters to your views layer.filters property. Check the docs for more info:
https://developer.apple.com/library/mac/#documentation/graphicsimaging/reference/CALayer_class/Introduction/Introduction.html
Maybe this is something for you? Haven't tried it but read about it in a post once:
StackBlur
Ow sorry, I read your post again and this extension is about blurring an UIImage, and you said that this was something you didn't want...
Well I'll leave it here anyways if people go googling for blurring an image..
Sorry :(