Vuforia hide marker - augmented-reality

Suppose you have a marker for your Vuforia AR application and when the digital object appears, you want to hide or cover the marker, like so:
https://youtu.be/eTLr8mN3_yw?t=15
Any ideas on how to do it?

You can think of this as one of those coloring book AR examples. Rough explanation would be reading the colors of fingers and wrapping around the target with that color.
Take a look at here https://github.com/maximrouf/RegionCapture

Related

How is marker recognition done in ar.js? How can we improve recognition efficiency?

I want to know how exactly the marker is generated/recognized so that I can make it more efficient in my code. Is there any way of making something a marker other than a patt file?
I was trying to use alphabets as markers and when displaying many letter-markers in one frame, it fails to detect the right one. So I wanted to make any random, clear image with the black border to be recognized.
You can use Jerome's maker generator to produce a marker of any image, but the image should be rotationally assymetric as per the ARToolKit docs

I need help to draw an icosahedron 3D object in an UIKit app

Although I am quite experienced with most frameworks in iOS, I have no clue when it comes to 3D modelling. I even worked with SpriteKit, but never with something like SceneKit.
Now a customer wants a very ambitious menu involving a 3D object, an 'icosahedron' to be exact. I want it to look something like this:
So I just want to draw the lines, and grey out the 'see-through' lines on the back. Eventually I want the user to be able to freely rotate the object in 3D.
I already found this question with an example project attached, but this just draws a simple cube: Stroke Width with a SceneKit line primitive type
I have no clue how to approach a more complex shape.
Any help in the right direction would be appreciated! I don't even need to use SceneKit, but it seemed like the best approach to me. Any other suggestions are welcome.
to build an icosahedron you can use SCNSphere and set its geodesic property to YES.
Using shader modifiers to draw the wireframe (as described in Stroke Width with a SceneKit line primitive type) is a good idea.
But in your case lines are not always plain or dotted — it depends on the orientation of the icosahedron. To solve that you can rely on gl_FrontFacing to determine whether the edge belongs to a front-facing or back-facing triangle.

Advice for library with GeoSpatial Mapping that allows users to place moving objects on a 2D map

I'm looking for a library/framework/toolkit that will allow me to render a 2D map from real GeoSpatial data and draw objects on the 2D map.
Requirements:
Map Tiling (when I zoom into the map, i want a more detailed image)
Pan (ability to use the mouse to move around the map)
Read various Geospatial images (satellite, street, etc)
Ability to draw objects onto the map (based on lat/longs) and have them move. For example, I want to be able to put an image of a bird on the map and have it move and rotate correctly.
Primitive shapes. It would be nice if it had built in ability to draw lines, circles, etc.
Complex drawing. For example, I want to draw a compass and have it show the heading of the current heading of the bird.
Mouse input. I want to be able to right click on the map and have a context menu appear. I want to click and hold an shape I draw on the map and drag it easily.
What I have looked at:
OpenSceneGraph with osgEarth. It's great, and fulfills my reqs, but is really slow and I had to do a lot of weird things to get things to work (especially with dragging objects on the map).
Cesium: looks promising, but somewhat slow, and I need it to work as a desktop application. I've seen online that some have managed to use Cesium inside Qt's Webkit, but I'm not sure I would want to take that risk.
EDIT:
I really want to stay away from a web-based framework if possible.
http://imgur.com/52DaJtQ
Here is a primitive picture of what I'm want to achieve. The aircraft icon should move and the degree circle along with it. I want to be able to drag the green waypoints and have the lines redraw as I move a waypoint. The red sensor footprint should adjust to what the aircraft can see.
http://imgur.com/52DaJtQ
Google Maps, Open Street Map, Bing Maps.
I use OpenSceneGraph/osgEarth extensively and am not dissatisfied with its performance.
What kind of weird things did you need to do?
If you want, you can contact me privately to troubleshoot your situation. Me website is AlphaPixel.com and there's a contact form there.

Lightning Shadow effect in CORONA SDK

I am trying to create a spotlight effect in my story book such that as the character moves around from one location to the other then the light focus moves towards that same character.Is it possible to do that in Corona SDK? How can I do that coz sprites aren't
helping me.Any idea regarding this.
I found some reference telling me that I can't do that
http://web-c2.anscamobile.com/forum/2012/10/27/dynamic-shadows-2d
http://developer.coronalabs.com/forum/2012/09/13/lightingshadows
Those two threads seem pretty definitive. You could create a spotlight pretty easy, but you can't cast shadows and the light moves different directions very easily.
If you want to do a spotlight without shadows, just create an image that's all black with a transparent hole in them middle that has some feathering around the hole. Make the black partially transparent so you can see the scene but have it a bit darker. You can them move the image around to be your spot light. You can also do it with a maskk (see the Flashlight example in the sample code)

Coloring Shapes in iOS app

We are building an iPad kids application in which a kid is requested to color different shapes with specific color. For example, consider an image with sky and trees , etc. all overlapping and a kid has selected a color for example "Blue" and then he taps the sky , the sky should turn to blue otherwise it should say "wrong color"
My questions are:
1- How to implement the coloring of the sky only with the selected color. We have implemented a Coco2d Floodfilling but it is too slow.
2- How to tie each part of the image with a specific right color. We suggested loading a fully colored image in a background layer and testing it at the tap .... BUT how to implement it.
Thanks
Are the shapes originally vectorial? If so, a solution would be to work directly with them as vectors, parsing them into CoreAnimation shapes.
You can give a try to SVGKit or get some inspiration from it. You'll get CAShapeLayers where you can change the fillColor property.
I believe that this way would be much more responsive (and the app size much more lighter) than doing tricks with images ;-)

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