I need to visualize stuff and want to ask for some hints and tutorials. Or which technique to use (Cocos2D, OpenGL, Quartz, ...)
Anyone here who did Visualization on iOS Devices?
It's about moving objects, fading, particles and more...
Any help is appreciated. I attached two examples.
It depends on what you what to present. For something like the very organic color blobs on the left, OpenGL is probably the way to go. For something more crisp and regular like the chart of the right, CoreAnimation layers are probably a good approach because they would be easy to work with yet also performant.
OpenGL does take more work to understand but of course in the end is going to offer the most flexibility, so it's more a matter of deciding how far down the graphics rabbit hole you really want to go.
Related
ask a general question. There are few sprite resources and they are hardly liked by me. I would like to learn from the absolute scratch, such as how do I create a sprite from my idea.
Can I ask do I create it this way or what's the standard process?
1. draw it on white paper
2. scan it into a .png jpg etc
3. render it in photoshop
Thanks.
It's not quite right for Stack Overflow indeed, but I have a few suggestions anyway.
If you want to hand draw your art there are a few approaches. I started drawing the resources I needed on paper and scanning them, but this raises a couple of problems.
The first problem is that it can be hard to remove the white background properly leaving nasty bitty edges. This can be solved with time, practice and patience, and as far as I know there is no good way around this.
When using paper, it can be very hard to get clean areas of solid color. Pencils and the like leave and extremely distinctive paper texture, but approaches that give more solid colors using inks tend to go very blotchy.
The other problem is that if you want to animate these, or indeed reuse part of one sprite in another, you're left drawing bits of sprites - this lead me on to my currently favored methodology.
My recommendation would be to use ink onto acetate. You'll need to do some research into the best inks to use, but it means you can build the sprites in layers, much like animators used to do for film back in the day. You still have to solve the white background problem after scanning though, and if you pick the wrong ink it can be very easy to smudge your drawings - not ideal.
The other, more expensive alternative is to use a graphics tablet, and cut out the paper/acetate stage all together. This solves the white background problem, but some people find drawing with tablets oddly difficult - myself included.
Adobe software wise - I would personally use Illustrator while working with a graphics tablet, Photoshop for making adjustments to the resulting images, and Fireworks for building UI interface elements.
Hope this helps!
This is not really a coding question. As far as I know stackoverflow is only for technical problems. That said, I would recommend Illustrator to get started. There are some great tutorials out there. :)
I have to implement long exposure photo capabilities to an app. Since i know that this is not really possible i have to fake it. It should work like "Slow Shutter" or "Magic Shutter".
Sadly i got no clue how to achieve this. I know how to take images with the camera (through AVFoundation) but i'm stuck at merging them to fake long shutter times.
Possibly i need to manipulate and combine all the images with coregraphics but i'm not sure about this (even the how). Maybe there's a better solution to this.
I would appreciate every help i can get here,
thank you people!
You might try the plus lighter blend mode.
Well, I suppose it would be possible to average together the results of several shots. I've mucked around a bit with the core graphics stuff to resize images (averaging together adjacent pixels), but with lower res images. The algorithm I used is here -- maybe it'll give you some ideas.
There may, of course, be a better way, and some tricks for working efficiently with high-res images. Can't help you there.
Convert the images to pixel bitmaps. Align and stack the bitmaps. Then try applying various 3D convolution filters to the 3D pixel array.
I'm currently trying to write an app, that would be able to show the effects of glas, as seen through the iPhone Camera.
I'm not talking about simple, uniform glas but glass like this:
Now I already broke this into two problems:
1) Apply some Image Filter to the 2D-frames presented by the iPhone Camera. This has been done and seems possible, e.g. in the app: faceman
2) I need to get the individual lighting properties of a sheet of glas that my client supplies me with. Now basicly, there must be a way to read the information about how the glas distorts ands skews the image. I think It might be somehow possible to make a high-res picture of the plate of glasplate, laid on a checkerboard-image and somehow analyze this.
Now, I'm mostly searching for literature, weblinks on how you guys think I could start at 2. It doesn't need to be exact, in the end I just need something that looks approximately like the sheet of glass I want to show. And I'm don't even know where to search, Physics, Image Filtering or Comupational Photography books.
EDIT: I'm currently thinking, that one easy solution could be bump-mapping the texture on top of the camera-feed, I asked another question on this here.
You need to start with OpenGL. You want to effectively have a texture - similar to the one you've got above - displace the texture below it (the live camera view) to give the impression of depth and distortion. This is a 'non-trivial' problem, in that whilst it's a fairly standard problem in its field if you're coming from a background with no graphics or OpenGL experience you can expect a very steep learning curve.
So in short, the only way you can achieve this realistically on iOS is to use OpenGL, and that should be your starting point. Apple have a few guides on the matter, but you'll be better off looking elsewhere. There are some useful books such as the OpenGL ES 2.0 Programming Guide that can get you off on the right track, but where you start would depend on how comfortable you are with 3D graphics and C.
Just wanted to add that I solved this old answer using the refraction example in the Khronos OpenGl ES SDK.
Wrote a blog-entry with pictures about it :
simulating windows with refraction
I need to draw two lines of text in a 3D perspective. They're not just flat characters, they are really 3D models and need to animate as well. Preferably with a glossy effect on them.
It sounds really complex to me and I have no experience with OpenGL. Are there frameworks that make this easy or am I looking at a difficult and timeconsuming task?
use cocos3d. cocos3d link here.
That kind of functionality on the iPhone requires plain OpenGL knowledge. You'll need to learn OpenGL and implement all of this by yourself. I know OpenTK is being ported to iPhone but that's not done yet. Good luck!
This isn't strictly a programming question, but I'm asking it here because it's certainly a software development question, if you take "software development" to include all aspects of creating a software system.
I am an independent iPhone developer. Except for translations, I handle all aspects of my apps myself—graphics included. I have to create icons, buttons, and UI elements of all sorts on a regular basis. I've learned a few tricks along these lines, and while they're certainly not works of art, I can effectively use gradients, shadows, border strokes, transparency, and textures to create minimalistic, attractive effects.
So far, I've used a vector drawing tool called VectorDesigner for all of my development, with occasional raster postprocessing by Pixelmator. It's worked mostly okay so far, but VectorDesigner has a host of issues:
It uses a package format for its files, which interferes with the use of Subversion.
It is very much a print tool, and I have to be very careful not to end up with objects on fractional pixel values which cause antialiasing.
While you can take the union or intersection of shapes, or add and subtract them, curves tend to deform with repeated boolean operations, sometimes quite dramatically.
And it offers very little control over strokes, to the point where I barely use them.
So I'm looking for a better tool for this specific purpose: shape-based drawing of simple icons, buttons, and UI elements on a Mac by someone without graphic design training. Good functions for exporting would be a plus—ideally it should be almost as easy to export a PNG to the place it goes in my project as it is to save (not save as) the file.
The perfect tool for me would be one that would allow you to define an object's shape by stacking up areas and masks defined by primitive shapes (which would remain separately editable), then define properties on those objects like transforms and strokes. I have no idea if something like this exists, though.
Adobe's tools generally strike me as very heavyweight, and are usually expensive, but I suppose they're a possibility. (Fireworks, with its emphasis on screen design, seems like it might be particularly suitable, but I don't know that much about it.) But what else is out there? If you're in a position like me, what do you use? What do you recommend?
Edited to add: Of course a graphic designer could get better results from an ancient copy of MacPaint than I could from Illustrator CS5. No tool can replace skill and taste, and many programmers have little of either. I'm aware of that. But I'm fortunate enough to have at least some taste—enough that my users compliment my apps' appearance in their reviews. I'm not hugely talented, but I do know my limitations, and I don't let myself produce anything ugly. Given my budget, that will have to do for now.
Try Opacity. A little rough on the edges, but one of the coolest and most unique features they have is export as source code (in Quartz, Cocoa, Cocoa Touch, or Canvas)
I'd suggest OmniGraffle
OmniGraffle is easy to use, can save as a PNG, can create binary non-package files (it's an option in the interface). You can also set the units to pixels to ensure exact alignment. (Canvas Size -> Ruler Units)
Finally, the Graffletopia website has some nice iPhone stencils for getting it right:
http://graffletopia.com/search/iphone
I think the only acceptable answer here should be "hire a designer".
But it sounds like Pixelmator/Inkscape are your best bets.
Though if you do find something better, that'd be really cool. Like a jQueryUI but for native.