I have a flat pan and using kinetic v1.
I want to receive the angle of the pan using kinetic camera.
for eg: If I put the angle in 45 degrees so kinetic will read the closet or exact angle it placed.
is this possible or any solutions ?
Thanks.
I don't know exactly how the data comes back in Kinect V1 but I believe this methodology should work for you.
First: You have to assume that the Kinect is your level of reference, if it is necessary to get the pans angle relative to the ground then make sure the Kinect is level with the ground.
Second: Separate the pan data from all other data. This should be straight forward, the pan should be the closets object so transmit the closest measurements into 3D coordinate points (array of x,y,z).
Third: Assuming you wish for horizontal angle find the highest and lowest grounds of data and average their depth from the camera. Then save both those depths and the vertical distance they are away from each other.
Fourth: Now you can essentially do the math for a triangle. Given you know the width of the pan(saves steps to know the objects size otherwise you have to estimate that too) you can solve for a triangle with sides a: distance to point 1, side b: distance to point 2, side c: size of pan and finding the angle of where points a and c or b and c meet will give you the horizontal angle of the pan relative to the Kinect.
Fifth: For verification your measurements came back correct you can then use the angle you found to calculate the width of the pan given the angle and distance of the top and bottom most points.
Needless to say, you need to make sure that your understanding of trig is solid for this task.
Related
Considering the camera is not tilted, it is easy to get the distance. However, can you refer a source where camera is tilted at some angle on y axis. By tilt i mean pitch. Also the camera is not looking directly at the object.
I am using 9-axis IMU fused orientation data and I need to convert quaternion pose to Euler angles for purposes of graphing the data to user. I want my all three angles to be from range [-180, 180] and I found a lot of references how to do that easily.
Roll and yaw work well but when the pitch crosses +90 degrees it starts going back towards -90 and then back to 0, as I increase Y component of my quaternion. This video explains it better.
You can also see the raw data from the sensor on this image:
There are in total three full rotations around each of the axes one after another. First two (solid red and green lines) are OK. Blue one (misslabelled "roll" on the plot, but is actually pitch rotation) does well until it reaches -90 degrees and then flips the direction until +90 and goes back to 0. At the same time this happens, both of the other axes give wrong readings (very fast change).
Is there a way of circumventing this issue around +-90 degrees and computing absolute pose in world frame?
First off, I am not sure if this is the right place so I apologize if this belongs elsewhere - please let me know if it does. I am currently doing some prototyping with this in VB so that's why I come here first.
My Goal
I am trying to make a program to be able to log different types of information for a video game that I play. I would like to be able to map out the entire game with my program and add locations for mobs, resources, etc.
What I have
The in game map can be downloaded so I have literally just stuck this in as a background image on the form (just for now). The map that I get downloaded though is not exactly as the map appears in the game though since the game will add extra water around everything when scrolling around. This makes it a bit tricky to match up where the origin for the map is in game compared to where it would be on the downloaded map.
The nice thing though is that while I am in the game I can print my current coordinates to the screen. So I thought that maybe I can somehow use this to get the right calculation for the rest of the points on the map.
Here is an example image I will refer to now:
In the above map you will see a dotted bounding box. This is an invisible box in the game where once you move your mouse out of the longitude and latitude points will no longer show. This is what I refer to above when I mean I can't find the exact point of origin for the in game map.
You will also see 2 points: A and B. In the game there are teleporters. This is what I would use to get the most accurate position possible. I am thinking I can find the position (in game) of point A and point B and then somehow calculate that into a conversion for my mouse drag event in VB.
In VB the screen starts at top-left and is 0,0. I did already try to get the 2 points like this and just add or subtract the number to the x and y pixel position of the mouse, but it didn't quite line up right.
So with all this information does anyone know if it is possible to write a lon/lat conversion to pixels based on this kind of data?
I appreciate any thoughts and suggestions and if you need any clarification of any information I have posted please let me know and I will be happy to expand on it. I am really hoping I can get this solved!
Thanks!
EDIT:
I also want to mention I am not sure if there is an exact pixel to lat/lon point for the in game map. I.e. the in game map could be 1 pixel = 100 latitude or something. So I might also need to figure out what that conversion number is?
Some clarifications about conversion between the pixel location to 'latitude and longitude'.
First the map in your game is in a geometry coordinate system, which means everything lies in 2D and you can measure the distance between two points by calculate the pixel position.
But when we talk about longitude and latitude, we are actually talking about a geography coordinate system, which is a '3D' model of the sphere oabout the surface of the earth. All the maps on earth are abstracted from 3D to 2D through one step called projection. Like google maps or your GPS. In this projection process, the 3D model converted to 2D model but there is always some part of the map will be tortured, so that same distance in pixels on a map could be different in length in reality.
So if you don't care about the accuracy then you can consider the geometry point as geography point. Otherwise, you need to implement some GIS library to handle the geodesic distance and calculate the geography point based on the projection coordinate system.
I understand that CalculateFrustumPlanes() in Unity3D returns an array of Plane objects, each representing a different frustum plane, but I can't find any documentation to suggest which element is which?
for example
[0] = Front
[1] = Back
etc.
I need to calculate whether a point in space (like the centre point of a Bounding volume) is in the camera frustum, for a Quad tree system.
What is exactly the order of the Planes in the returned array is not documented (and I don't know it).
Anyway I think you can figure it out without much effort: you just need to put the camera in a well know orientation and check the normal value's of each Plane.
I need to calculate whether a point in space (like the centre point of
a Bounding volume) is in the camera frustum, for a Quad tree system.
For a Quad Tree system, I think the intersection between the frustum and a GameObject's AABB is enough, so you don't even need to know exactly the order of the Plane's in the array to compute it. You can just use GeometryUtility.TestPlanesAABB.
Order: left, right, bottom, top, near, far.
I've found this beautiful quick way to remove gravity from accelerometer readings. However, I have a 6dof IMU (xyz gyro, xyz accel, no magnetometer) so I am not sure if I can use this code (I tried and it doesn't work correctly).
How would someone remove the gravity component? It's a big obstacle because I can't proceed with my project.
EDIT:
What I have:
quaternion depicting the position of aircraft (got that using Extended Kalman Filter)
acceleration sensor readings (unfiltered; axes aligned as the plane is aligned; gravity is also incorporated in these readings)
What I want:
remove the gravity
correct (rotate) the accelerometer readings so it's axes will be aligned with earth's frame of reference's axes
read the acceleration towards earth (now Z component of accelerometer)
Basically I want to read the acceleration towards earth no matter how the plane is oriented! But first step is to remove gravity I guess.
UPDATE: OK, so what you need is to rotate a vector with quaternion. See here or here.
You rotate the measured acceleration vector with the quaternion (corresponding to the orientation) then you substract gravity [0, 0, 9.81] (you may have -9.81 depending on your sign conventions) from the result. That's all.
I have implemented sensor fusion for Shimmer 2 devices based on this manuscript, I highly recommend it. It only uses accelerometers and gyroscopes but no magnetometer, and does exactly what you are looking for.
The resource you link to in your question is misleading. It relies on the quaternion that comes from sensor fusion. In other words, somebody already did the heavy lifting for you, already prepared the gravity compensation for you.