Collision Detection in Box2d (cocos2d ) - ios4

I have made 10 different static body placed along straight path. I want to detect Collision of a moving body with these different static body. How can i detect the collision of specific object(without using TileMap)?

This tutorial is very helpful for Collision detection:
http://www.raywenderlich.com/606/how-to-use-box2d-for-just-collision-detection-with-cocos2d-iphone

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Add BullsEye to Image (changing pixels)

I am trying to add a target (bullseye) to an image without the use of importing python functions, it is proving to be rather difficult however I believe I need to define a circle through use of code. It should be done by changing the pixels as opposed to importing functions.
Thanks
Needs to be in the centre of an image
You will need to add more information here - how is your image represnted in Python? Normally for porduction code, dealing with images is done through 3rd party modules, each of which have a way to draw or change different pixels. If you are using none you have to define your image reading and writting code (or a way to display the image on the screen).
Anyway, doing all of that without any "importing" will be quite artificial, though feasible.
Maybe you should use pnm files which have a minimum of encoding required.
That said, you could represent the image in memory as a bytesarray object, and use math.sin and math.cos (you will have to import those, or resort to a "raytracing" approach which can render the circle based on x**2 + y * 2 = r ** 2 ) to draw your circle.

Drawing icons in the middle of polygons - earth plugin

I was wondering if there is a good way to draw icons (markers) in the middle of polygons, using kml in google earth plugin.
Currently I solve this by calculating the middle, and for every polygon adding a placemark with the icon in the calculated center.
But then i have to make sure that when I remove the polygom I remove the marker also.
Is there a way to make them connected and not seperate like that?
Thank you!
You could encapsulate the placemark and polygon objects into a single object, allowing you to create custom "PlacemarkPolygons" passing in any options you require. So you would have.
function PlacemarkPolygons(options) {
// your set up...
}
To see what I mean take a look at this "CustomOverlay" example that wraps a groundOverlay and a polygon to provide click events for the groundOverlay.
http://jsfiddle.net/2bUXQ/
Although the Google Earth API objects are different from yours, the principal would be exactly the same. You would define a custom object that wraps the two API objects that you want to associate together, along with any methods that help you to use it.

Adding SVG overlay to nokia HERE map

I'm working with nokia HERE maps and I want to add an additional layer of visualization graphics on top of a map. Since the possibilities to interact, manipulate and customize the graphics created by the HERE api are limited, I would like to work with d3.js/SVG for my visualizations.
My straight forward and obvious solution would have been to just add an absolute positioned SVG element on top of the map and giving it the same dimensions. But of course that takes every possibility to interact with the map. Is there any solution to add an overlay to the map which allows me to put SVG on it while maintaining the full interactivity (panning, zooming, clicking) of the map? Also it should be possible to interact with the SVG.
I know that there is a possibility to add a custom overlay of tiles provided by a tile server to HERE maps but that's not really what I'm looking for. I'm looking for something like the solution google has to offer to this problem. A set of custom layers which are always in sync with the corresponding map and have their own initialize, draw and remove methods. Is there something similar for HERE maps?
I think you are after the nokia.maps.map.provider.CanvasProvider class. This class provides a ground overlay bound to a specific area which offers a draw() method. The attach() method is the equivalent of your intialize I think, and you can refresh the overlay using update().
Depending upon your use case, I've also found the following techniques useful regarding SVG, Images and HERE Maps:
For an SVG marker which is anchored to a point and doesn't resize
use: SVG Markers
Alternatively override the Marker class and write using the low
level graphics commands to add flexibility to the rendering of a
marker anchored to a point. Like this: Defaced Marker
To add an image bound to a specific area use the ImageProvider class
To add a series of tiled images from a TMS (Tile Map Service) use the ImgTileProvider class
Alternatively if the [zoom][col][row] is useful to you and you
want to write SVG based stuff yourself try something like this example - which combines
SVG with 256x256 pixel markers.
Note that the HERE Maps API for JavaScript only supports SVG Tiny.
A class like the old nokia.maps.map.provider.CanvasProvider isn't even available on the new v3 API from Here.
Your best bet is on Leaflet using custom providers loading Here map tiles. Then you just load this Custom Overlay class and you're all set to draw D3, WebGL, whatever you need. Leaflet only loads the tiles from the providers and exposes some simple APIs. You will not have to deal with any of the providers' APIs.
Just don't forget to add your app_id and app_code to the provider class.

Creating a synthetic camera in vtk and manipulating the intrinsic parameters and extrinsic interactively

I want to render a scene interactively. The controls are already provided so that you can position the camera with mouse but you never know the exact value.
I want to manipulate the internal camera values as well e.g focal length.
Externally I want to set the translation and rotation of the camera.
I want to give all the values manually. Could anyone please help to point to such a demo or a code snippet to do it. Preferably in python.
Thanks a lot.
You can get the camera from the renderer with renderer->GetActiveCamera(). Then you can manipulate it using the class functions: http://www.vtk.org/doc/nightly/html/classvtkCamera.html
Here is a simple Python example: http://www.vtk.org/Wiki/VTK/Examples/Python/Camera

AVVideocomposition AVPlayerItem position of video-layer

I used Apple's AVEdit-Demo, tweaked it a little and was able to add CALayers with animations and images to the video-composition. So far, this works fine.
It uses AVVideoComposition and AVPlayer/AVPlayerItem to merge videos (and show them - the export rendering is a little different).
I added a layer with a png with some transparent areas, sort of like a mask, that hides parts of the video. Now I need to move the video-layer, so I can adjust the hidden parts (a.k.a. the visible part). The Mask covers the whole screen (in a CALayer), so moving the Mask-Layer isn't an option.
I didn't find any properties or methods, to adjust the position of the video-layer...
Any Ideas?
Found it...
I had to access the AVMutableCompositionTrack in the AVMutableVideoComposition and set the preferredTransform there (CGAffineTransformTranslate).
However - the Docs state, that this should be possible in a AVMutableComposition as well (AVAssetTrack setPreferredTransform).
I couldn't get this to work, though.

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