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.
Related
I want to create some objects (boxes, cylinders, pyramids, doesnt really matter) which display text / a number on the side / on all of it's sides. Short of making individual materials with the numbers displayed on them by hand, is there a simple way to achieve this?
I am using Swift 4 in XCode.
First thing, please try not to be discouraged. Thank you for reaching out to the ARKit community on stack :-)
We are here to help each other.
(I do feel your pain…and why I am trying to help)
Here is an interesting stack page that has helped me with placing items on the sides of objects(like boxes cylinders, pyramids).
I hope it can help you or others.
SCNBox different colour or texture on each face
Rickster pointed out some other possibilities.
We all learn by sharing what we know.
Smartdog
Depends on what you mean by "by hand". If you want the text displayed on the surface of the geometry, like a texture map, then texture-mapping it is the way to go. If you draw your text into a UIImage, you can set that as the material contents, which is a bit more dynamic than, say, creating a bunch of PNGs that each have a different number on them. Just make sure to choose an image size/resolution that looks good at the size your objects are displayed at.
For anyone lost in the internet trying to find an answer to this it's stupidly simple. Use SCNText and set it as a node. I just wasted 7 hours of my life trying to make number .dae models position themselves next to each other because there is no mention of this feature anywhere.
I hope I saved you as much pain as I just endured discovering this.
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 =)
New user to the site, but I have used it in the past so I felt it best to ask my question here, for the best chance of getting a response.
What I'm dealing with is one object, this being the sprite for my latest app, which I need to check for when it comes in to contact with another object, in this case, a tunnel which will curve.
Now, I'm aware of CGRectIntersectsRect, however I can't see that being helpful, as if I've got 2 UIImages, that being the top and bottom of a "mountain", and said pieces curving, there's no doubt that the sprite would touch the "rectangle".
What I need is something to trigger when the sprite hits the actual wall, however my limited knowledge of Objective-C isn't helping my case.
I imagine someone out there will know what I can do to resolve this, as for all I know it could be a simple solution.
Thank you in advance everyone!
First, I'd probably not build these basic pieces yourself. For iOS 7, you can use SpriteKit, which is built-in. If you want to support older versions of iOS, look at cocos2d (it's good for iOS 7, too).
But to the question, one approach for detecting arbitrary overlaps is to draw both objects into a buffer and check if there are any overlapping pixels (for instance, by drawing one in in pure red, and another in pure green, and then looking for pixels that have both). For a discussion of how to do this kind of thing in Core Graphics, see Clipping a CGRect to a CGPath, which provides sample code for the simplest version (checking for the intersection of a rectangle and curve), but the same approach can be used more generally. Note that this drawing can get expensive if you're doing it constantly, so usually you first check whether the bounding rectangles overlap. That tells you whether it's even worth the trouble to look closer.
But first I'd look at SpriteKit.
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).
I am working on a Cocos2d project for iPad and iPhone, and now I need to develop something that looks too small for iPhone.
My first approach was to redesign it to make it possible to look bigger, but then I though that a region zoom effect would be great. The bad point is that I don't know how to do it... I really don't know what would be the correct/best approach to do it.
I have already checked out the Cocos2D CCLens3D build in effect, but it doesn't give me the results I want.
I would love to get the same result than when you long-press a textview/textfield on the UIKit:
Thanks in advance for your help!
If your still looking for a solution:
http://rombosblog.wordpress.com/2012/06/03/magnifierglassforcocos2d/
Uses CoreGraphics to render. Although this implementation works (requires some tweaking), I found that it lacked that Gaussian distribution effect I was looking for and was quite expensive if you updated the magnifying effect in a small interval.