I want to develop an application that in one of the steps move the spark programmatically, something as “elevate during 1 second” or “move left during 5 seconds”, or maybe "move one meter to the left" this after pushing one button in the mobile application.
I’m unable to find this kind of functionalities in the API, or code examples.
The more similar functions are:
GoToAction(LocationCoordinate2D coordinate) or
GoToAction(float altitude)
My question is: This can be done? Or Can I move the spark without knowing the destination coordinates?
Shy of knowing the coordinates and using waypoints, you might want to consider virtual joystick.
Using virtual joystick you can move in a small fashion as using the controller, no destination location need. However, the caveat is that you must make movement calculations yourself in order to set the direction, speed, e.t.c.
Related
I would need to make my dron Mavic2 Pro to visit approx 10 locations in relatively low altitude 1.7 m. In each location the camera should look at right direction and the mission paused to let the mobile application process some CV tasks. I am not sure what is the best approach to make a mission that is partially processed on mobile platform? What to use in DJI mobile sdk api to pause mission when the location is reached?
I am going to use a time line mission composed from sequence of GoToAction. I wonder if this is a good way to do it. Is there a better solution?
Is MissionControl.Listener right place to interrupt a mission when a TimeLineElement finish or should I use WaypointReachedTrigger?
I wasn't able to find any suitable example.
Please add specific programming question. Otherwise, all answer is primarily opinion-based see https://stackoverflow.com/help/dont-ask for detail
DJI method allows you to control the drones gimbal and gps navigation through MissionAction. The gotoaction is a subclass of the Missionaction class. the gotoaction only goes to some GPS location . So you need other things in the mission action such as gimbalattiudeaction and camera capture action to perform camera pointing and capturing. See the Fig below.
For CV tasks, it is easy to link DJI app to OpenCV. But I highly not recommend you to do so as the task such as dection using CNN system takes too much resources. The popular approach is to upload the image taken in local buffer to a local server with GPU for processing in near real-time manner. See the Fig below, I`m using WSDK with windows online OCR for detection. Video at https://youtu.be/CcndnHkriyA . I tried with local phone based approch, but result is limited by the model accuracy. And I could not apply high accuracy model because of the processing demand for such model is high. You can see my demo in the Fig below
What you want is pretty ez to implement but hard to perfect. Flying in low altitude(1.7m) requires you to have some degree of obstacle avoidance and GPSless path planning. The one implemented in Mavic hardware is only simple avoidance or slip through. For a bit more complex like go around a wall or maze-like environment, it better to add your own global path planer and local path planner. For the feedback you can use the SVO method to get odometry and map the local sparse obstacle map for inflated radius calculation. See Fig below.
Fig taken from video https://www.youtube.com/watch?v=2YnIMfw6bJY.
The feedback code is available at https://github.com/uzh-rpg/rpg_svo.
The path planning code you can try with ETH`s https://github.com/ethz-asl/mav_voxblox_planning as well.
Good luck with your work.
I have an android application which is getting gesture coordinates (3 axis - x,y,z) from an external source. I need to compare them with coordinates which I have in my DB and determine whether gesture is the same/similar or not.
I also need to add some tolerance, since accelerometer (device which captures gestures) is very sensitive. It would be easy, but I also want to consider e.g. "big circle" drawn in the air, same as "small circle" drawn in the air. meaning that there would be different values, but structure of the graph would be the same, right?
I did some research and I found out I could use Dynamic time wraping possibly in combination with Hidden Markov model.
I tried to do some further reading on it, but I didn't find much. I just found a Java library called FastDTW but can't figure out which methods are the right ones for my problem.
Would you please provide me any lead on this?
See these images, they are the same gesture but one is done in a slower motion than another.
Faster one:
Slower one:
I haven't captured images of the same gesture where one would be smaller than another, might add that later.
I am building an OS X game using Swift and the SpriteKit framework. I don't know, what kind of game map I should use in the project. I started with a .sks file and it might work, but seems too time-consuming.
Screenshot of my crude .sks map.:
I need to have access to the position of the solar system nodes so I can center the map on any of them. I need to hide parts of the map. Also, I need to be able to get the angle between solar systems.
On a small scale, I could make this work with the .sks, but I am going to add maybe around a hundred solar systems, so individually placing solar system nodes and struggling with shape nodes to form the lines between the solar systems is simply ridiculous.
This is my first game map, so I am completely oblivious to the different kinds of file types and applications I could use to make the map.
I would go with a database (NSArray? NSDictionary?) of solar systems. Each entry in the db would have all information for that solar system (name, coordinates, planets, moons, etc.). Warping between solar system would change which entry is used to redraw the screen, etc. (Note: NSArrays and NSDictionarys can be easily loaded and saved to (text editable!) XML files.)
So I know about setSurface, and have no problem using it as an overlay or whatever - its on a surfacecontrol. That said, I am stumped about getting pixel data
1) I've tried everything I can think of (the control, the root, etc) to use the drawing cache functions to get the bits for the camera surface. Yah, no. The cached bitmap is always zerod out.
2) I've used both SurfaceView and GLSurfaceView successfully as a setSurface taget. I cannot use any other class, such as TextureView.
3) I've investigated the C API and I see the camera exposes connectOnFrameAvailable, which will give me access to the pixels
My guess is that the internal tango logic is just using the surface in java to gain access to the underlying bit transfer channel - in the C API it requires a texture ID, which makes me suspect at the end of the day, the camera data is shipped in to the GPU pretty quickly, and I bet that CUDA lib operates on it - given the state of things, I can't see how to get the bits on the Java side without rooting the device - just cause I have a texture or simple surface view rendering raw bits on the screen doesn't mean I can get to them.
I don't want to peel the image data back out of the GPU. I'd need to switch my busy animation from a watch to a calendar for that.
Before I dive down into the C API, is there any way I can get the camera bits in Java ? I really want to be able to associate them with a specific pose, but right now I can't even figure out how to get them at all. I really want to know the location and color of a 3D point. Camera intrinsics, the point cloud, and the 2d image that generated the point cloud are all I need. But I can't do anything if I can't get the pixels, and the more questionable the relationship between an image and a (pose and a pointcloud) the sketchier any efforts will become.
If I do dive into C, will the connectOnFrameAvailable give me what I need ? How well synced is it with the point cloud generation ? Oh, and have I got this right ? Color camera is used for depth, fisheye is used for pose ?
Can I mix Java and C, i.e. create a Tango instance in Java and then just use C for the image issue ? Or am I going to have to re-realize everything in C and stop using the tango java jar ?
will the connectOnFrameAvailable give me what I need?
Yes, it indeed returns the YUV byte buffer.
How well synced is it with the point cloud generation?
The Tango API itself doesn't provide synchronization between the color image and depth point cloud, however, it does provide the timestampe which allow you to sync at the application level.
Color camera is used for depth, fisheye is used for pose?
Yes, you are right.
Can I mix Java and C (i.e. create a Tango instance in Java and then just use C for the image issue)
Starting two Tango instance is really not the way Tango supported, even though it works, it will be extremely hacky..
As the temp walk-around, you could probably try to use the drawing cache of the view?
While I have some experience with the WinAPI I do not have a ton, so I have a question for people who do have much experience in it. My question concerns what the limit of our power is. Can we change how windows fundamentally displays?
For example, can I cause windows to render a screen size bigger than the display and pan across it, kind of like workspaces but without separation? Can I apply distortion to the top and bottom of the screen? If distortion is not possible can I have an application mirror what windows is displaying with very little delay?
The biggest question I have is the first one, because if I can make windows render virtual workspaces and pan seamlessly between them then I figure it is possible to make a separate application which handles the distortion on a mirrored image of the desktop. Again, apologies for the vague questions, but I really want to know if we are able to do this stuff, at least in theory, before I dive deep into learning more on the API. If the WinAPI does not allow it is there another way to do this kind of stuff in Windows?
EDIT: Some clarification. What I want to do is basically extend the desktop to a very large size (not sure on exact size yet), both vertically and horizontally. Section the large desktop into workspaces of a specific size which can seamlessly be transitioned across and windows moved across. It would transition workspaces based on a head tracking device and/or mouse movement. Note that when I say workspaces this could be achieved by zomming in and then panning the zoom as well. I also need to be able to distort the screen, such as curving the edges, and render the screen twice. That is the bare minimum of what I am wanting to do.
Yes, you can. The most feasible way I come up with is using a virtual graphics driver (like what Windows Remote Desktop does, which creates a virtual graphics card and a virtual display). Sadly you will lose the ability to run some programs needing advanced graphics API (such as 3D games, 3D modelling tools or so).
There're some examples:
http://virtualmonitor.github.io/
https://superuser.com/questions/62051/is-there-a-way-to-fake-a-dual-second-monitor
And remember Windows has a limit on display resolution (for each and for altogether). I don't remember the exact number but it should be less than 32768*32768.