Matrix3D.pointAt in Silverlight 3.0 - silverlight-3.0

Has anyone one every created a method for Silverlight which does the same thing as Matrix3D.pointAt() does in Flash? In flash pointAt rotates a display object so that it faces a specified position. In my situation I want it to face the same direction as its velocity vector.

I'd recommend looking at Silverlight 3 plane projection which may achieve what you're trying to do: http://channel9.msdn.com/posts/ContinuumNews/Silverlight-PlaneProjection-perspective-transform-tutorial/

Related

Placing objects below the ground in AR Quick Look on iOS

I am working on a project that will display objects below the ground using AR Quick Look. However, the AR mode seems to bring everything above the ground based on the bounding box of the objects in the scene.
I have tried using the USDZ directly and composing a simple scene in Reality Composer with the object or with a simple cube with the exact same result. AR preview mode in Reality Composer is showing the object below the ground or below an image anchor correctly. However, if I export the scene as a .reality file and open it in using AR Quick Look, it brings the object above the ground as well.
Is there a way to achieve showing an object below the detected horizontal plane or image (horizontal) using AR Quick Look?
This is still an issue a year later. I have submitted feedback to Apple. I suggest you do too. I have suggested adding a checkbox to keep Y axis persistent. My assumption is this behaves this way to prevent the object from colliding with the ground, but I don't think it's necessary. It's just a limitation right now.

Any way to make AR.js camera less sensitive to movement?

After testing with default and custom marker/model of various size and distance, I concluded that the reason my AR models are having seizure (jittering/flickering/shaking like mad) is because of my hand movement. When the (phone) camera is at rest, the model is stable when the camera is stable.
Because the intention is to share the end product with the public (or anyone whose phone supports WebRTC), I can't calibrate the AR camera, because that would only fix my (phone) problem, not the other audience's.
Is there a setting in AR.js or ARToolkit that governs the sensitivity of the camera?
In case you are facing hard mad movements/hyper-sensitivity shaking of images with Ar.JS, and you are using multiple markers in the same page, the solution is to add a <a-entity camera></entity> inside the <a-scene> that contains the markers.
This avoids the automatic camera(s) created by a-frame, and makes everything more stable.
You could use the object position and orientation from AR.js and average that over a few frames to smooth things out.

How to track cube (with each side image changed) using vuforia or any other Argument?

I'm learning vuforia these days (https://developer.vuforia.com/).
I wonder how to track a rubik's cube ( with each side color changed).
As the Getting Started said , maybe I could use the Multi-Targets to repesent the cube. But each side of rubik's cube is different. I do not know how to upload the cuboid images for each sides..
Is there any other way ? Please show me some tips.
Thanks!

How to rotate an image in dart?

I'm trying to develop a simplistic 2D browser game with dart.
The player is drawn from a png-image represented by an ImageElement in dart.
I want the player-image to turn towards the mousepointer, but cant find how to rotate an image in dart.
Any suggestions as to how this might be done?
I would highly recommend using the StageXL library for this (https://pub.dartlang.org/packages/stagexl). It's basically a recreation of the Flash APIs for Dart. It makes doing that sort of thing very easy, and it's often used to create Dart games.
I ended up using multiple images for the 8 general directions the player can move and set them accordingly.

iOS augmented reality with compass and location

I'm trying to develop a mini "Around Me" like using camera, compass and location. I would like to display place's images on my screen.
For the moment I have my location and my orientation with compass. I would like to know how can I determine the position of the place I want to display.
Thanks for your help ;)
Once you have relative distance and bearing, which you can determine from two points in the same coordinate space using algorithms found on this page, figuring out where a known coordinate is with respect to a known viewpoint is basically a perspective projection, the math is outlined on this Wikipedia article. The rotation of the camera is given by the compass, and the tilt by the accelerometer (the position is of course, GPS).
I'm trying to find a better document - there are a couple of extra things to consider - like the camera parameters etc, but this is a good starting point.
If it's too involved (like if you're not comfortable with rotation matrices) we can break it right down to the simple trig.
The code in the iPhone ARKit project does this, and quite a bit more. While you may not be able to use their complete library, it is a great reference on the subject of augmented reality.
Check out 3DAR, it lets you add an AR view to a MKMapView app very easily. There's a video tutorial on this process, as well as some sample code, on the 3DAR site, www.3dar.us
You can create a location based AR app in Junaio. It's an AR browser. Free to use and deploy in (as long as it's not a custom app and in Junaio).

Resources