Say I have 2 NMAGeoCoordinates to place my NMAMapCircle on my NMAMapView. They are (33,180) and (34,180). Is it possible to animate the NMAMapCircle moving from coordinates (33,180) to (34,180)?
Just interpolate the latitude yourself over a fixed time? Keep changing the position of the maker will make it look like an animation. Normally we do this #30fps, but even at 15fps it looks pretty good.
Related
I found this interesting animation and wonder if it's possible to repeat it in the PaperJS? It seems like it could be made of a group of circles, rotated around another circle.
But the problem is - when these objects are in a group I can't use sendToBack() per each, it's not going to work. Here is the Sketch example, that doesn't work.
P.S. Here is a simplified version of how it could be achieved, but it works only for 1 element, and only for animation along one axis.
If you still want to have your object grouped, a basic solution could be to have 2 groups: one below and one above the circle and toggle items visibility.
Just to demonstrate the idea, this sketch extends your code in this way.
I think that the way you currently decide if the item should be below or above can be improved though for a better result (you could try to detect intersection between the item and the circle rather than only checking the position).
I have an problem: My 3d plot gets distorted, if I rotate or pan the plot. I know this behaviour is intended to show the user the most at all times, but it looks silly, so I want an orthogonal view or Axes which are equally long.
Earth distorted.
I have an WPF Application, where the ILN Form/Control is hosted via WindowsFormsHost.
I tried every possibility regarding Plotcube.Projection, have set Plotcube.Limits, changed ILN_Panel autosize etc. My next idea was that maybe I need to configure the WPF and/or Forms window itself.
Thanks!
I think that is not possible. At least not easy within PlotCube. If you do not need PlotCube just put the object into the Camera node and set Projection to Orthogonal. And you are done.
With PlotCube it is much more complicated. You must make sure that all containers have equal aspect ratio (width / height) WinformsHostControl, PlotCube, PlotCube.ScreenRect, PlotCube.DataScreenRect, PlotCube.Plots (data group), and its Limits. If you want to rotate everything free you must make sure to have equal aspect ration on all 3 dimensions wehere applicable.
If I have an object performing this CAKeyframe Animation path (it is just an oval shape in the upper region of an iphone..
UIBezierPath *trackPath = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(20, 100, 280, 150)];
Now imagine that at anytime during this paths travels I want to create a smooth path from its current position at a point in time and some point at the bottom of the screen.
By the way I am assuming that once I have a path I can stop the current CAKeyframeAnimation and add this path to a new CAKeyframe animation, but maybe if this is incorrect you can give me pointers here as well please.
So I said to myself "Self.....it looks like you are going to have to answer this one yourself as nobody even wants to edit it or say that it is a duplicate......"
So I was hoping for some easier or ready made way to do this. From what I have found there is no easy way. It seems the steps are going to be;
get the current position of the animated layer
calculate yourself with all your own code a nice smooth curve
add this path to an animation and animate it.
As for the calculation of a Bezier Curve I am still looking to find some class or code where points can be plugged into it and the two control points are produced for the UIBezier class to produce a curve.
In my case I am going to only animate "out" of my above questioned shape a determined points and thus have ready made smooth curves which I have prepared.
Animating a smooth exit from an oval at any point is very complicated and In my case just not worth it. So I have not done that.
The best example of what I am trying to achieve is on this youtube video
http://www.youtube.com/watch?v=53Tk-oGL2Uo
The letters that make up the word 'Atari' fly in from the edges of the screen spinning and then line up to make the word at the end.
I know how to make an object move across the screen, but how do I calculate the spinning so that when the object gets to its end position it's facing the correct direction?
The trick is to actually have the object(s) in the right position for a specific time (say t=5.0 seconds) and then calculate backwards for the previous frames.
i.e. before 5.0 seconds you rotate the object(s) by [angular velocity] * (5.0 - t) and translate by [velocity] * (5.0 - t)
If you do this, then it will look like the objects fly together and line up perfectly. But what you've actually done is blown them apart in random directions and played the animation backwards in time :-)
The CORRECT way of doing this is using keyframes. You can create the keyframes in any 3D editor (I use MAX, but you could use Blender). You don't necessarily need to use the actual characters, even a cuboid would suffice. You will then need to export those animation frames (again, in MAX I would use ASE - COLLADA would work with Blender) and either load them up at runtime or transform them to code.
Then it's a simple matter of running that animation based on the current time.
Here's a sample from my own library that illustrates this technique. Doing this once will last you far longer and give you more benefits in the long run than figuring out how to do this procedurally.
I'm doing some image processing, and I need to find some information on line growing algorithms - not sure if I'm using the right terminology here, so please call me out on this is needs be.
Imagine my input image is simply a circle on a black background. I'd basically like extract the coordinates, so that I may draw this circle elsewhere based on the coordinates.
Note: I am already using edge detection image filters, but I thought it best to explain with a simple example.
Basically what I'm looking to do is detect lines in an image, and store the result in a data type where by I have say a class called Line, and various different Point objects (containing X/Y coordinates).
class Line
{
Point points[];
}
class Point
{
int X, Y;
}
And this is how I'd like to use it...
Line line;
for each pixel in image
{
if pixel should be added to line
{
add pixel coordinates to line;
}
}
I have no idea how to approach this as you can probably establish, so pointers to any subject matter would be greatly appreciated.
I'm not sure if I'm interpreting you right, but the standard way is to use a Hough transform. It's a two step process:
From the given image, determine whether each pixel is an edge pixel (this process creates a new "binary" image). A standard way to do this is Canny edge-detection.
Using the binary image of edge pixels, apply the Hough transform. The basic idea is: for each edge pixel, compute all lines through it, and then take the lines that went through the most edge pixels.
Edit: apparently you're looking for the boundary. Here's how you do that.
Recall that the Canny edge detector actually gives you a gradient also (not just the magnitude). So if you pick an edge pixel and follow along (or against) that vector, you'll find the next edge pixel. Keep going until you don't hit an edge pixel anymore, and there's your boundary.
What you are talking about is not an easy problem! I have found that this website is very helpful in image processing: http://homepages.inf.ed.ac.uk/rbf/HIPR2/wksheets.htm
One thing to try is the Hough Transform, which detects shapes in an image. Mind you, it's not easy to figure out.
For edge detection, the best is Canny edge detection, also a non-trivial task to implement.
Assuming the following is true:
Your image contains a single shape on a background
You can determine which pixels are background and which pixels are the shape
You only want to grab the boundary of the outside of the shape (this excludes donut-like shapes where you want to trace the inside circle)
You can use a contour tracing algorithm such as the Moore-neighbour algorithm.
Steps:
Find an initial boundary pixel. To do this, start from the bottom-left corner of the image, travel all the way up and if you reach the top, start over at the bottom moving right one pixel and repeat, until you find a shape pixel. Make sure you keep track of the location of the pixel that you were at before you found the shape pixel.
Find the next boundary pixel. Travel clockwise around the last visited boundary pixel, starting from the background pixel you last visited before finding the current boundary pixel.
Repeat step 2 until you revisit first boundary pixel. Once you visit the first boundary pixel a second time, you've traced the entire boundary of the shape and can stop.
You could take a look at http://processing.org/ the project was created to teach the fundamentals of computer programming within a visual context. There is the language, based on java, and an IDE to make 'sketches' in. It is a very good package to quickly work with visual objects and has good examples of things like edge detection that would be useful to you.
Just to echo the answers above you want to do edge detection and Hough transform.
Note that a Hough transform for a circle is slightly tricky (you are solving for 3 parameters, x,y,radius) you might want to just use a library like openCV