angle

问题 I'm working on a android application and I need to estimate online camera rotation in 3D-plan using images from camera and opencv library. I like to calculate Euler angles. I have read this and this page and I can estimate homography matrix like here. My first question is, should I really know the camera intrinsic matrix from camera calibrtion or is the homography matrix (camera extrinsic) enough to estimate euler angles (pitch, roll, yaw)? If homography matrix is enough, how can I do it

问题 I want to know a way to flip an angle in a horizontal axis, without having to do many operations. Say I have an angle of 0 ("pointing right" in my code's coordinate system), the flipped angle should be 180 (pointing left). If 90 (pointing up), flipped it should still be 90. 89 is 91, and so on. I can operate on the X/Y speeds implied by the angle but that would slow things down, and I feel it's not the proper way to go. I don't know much math so I might be calling things by the wrong name..

问题 I have two points, (x1,y1) and (x2,y2) , that I'd like to draw a line between. I know I can figure out the angle (in degrees) of that line using arctangent and the slope: atan((y2-y1)/(x2-x1))*180/pi However, how would I convert this angle to a [0,360] scale? Basically, I want my angle to be on a compass scale in which "North" is 0 deg, "East" is 90 deg, "South" is 180 deg, and "West" is 270 deg. Thanks! 回答1: (450-atan2(y2-y1,x2-x1)*180/pi)%%360​​​​​​​​​​​​​​​ segmentToAngle <- function(x1,y1

问题 I have two points, (x1,y1) and (x2,y2) , that I'd like to draw a line between. I know I can figure out the angle (in degrees) of that line using arctangent and the slope: atan((y2-y1)/(x2-x1))*180/pi However, how would I convert this angle to a [0,360] scale? Basically, I want my angle to be on a compass scale in which "North" is 0 deg, "East" is 90 deg, "South" is 180 deg, and "West" is 270 deg. Thanks! 回答1: (450-atan2(y2-y1,x2-x1)*180/pi)%%360​​​​​​​​​​​​​​​ segmentToAngle <- function(x1,y1

问题 I have two points, (x1,y1) and (x2,y2) , that I'd like to draw a line between. I know I can figure out the angle (in degrees) of that line using arctangent and the slope: atan((y2-y1)/(x2-x1))*180/pi However, how would I convert this angle to a [0,360] scale? Basically, I want my angle to be on a compass scale in which "North" is 0 deg, "East" is 90 deg, "South" is 180 deg, and "West" is 270 deg. Thanks! 回答1: (450-atan2(y2-y1,x2-x1)*180/pi)%%360​​​​​​​​​​​​​​​ segmentToAngle <- function(x1,y1

问题 I am trying to generate a 3d tube along a spline. I have the coördinates of the spline (x1,y1,z1 - x2,y2,z2 - etc) which you can see in the illustration in yellow. At those points I need to generate circles, whose vertices are to be connected at a later stadium. The circles need to be perpendicular to the 'corners' of two line segments of the spline to form a correct tube. Note that the segments are kept low for illustration purpose. [apparently I'm not allowed to post images so please view

问题 For a 3D game engine I'm working on I need to calculate if two 3D triangles are on the same plane to display it accordingly. How do I calculate the angles of a triangle in 3D space? Would calculating a surface normal and comparing those ever give me 2 equivalent normals? 回答1: Why do you want to do that? What is the number of triangle you expect to test? It seems a little bit complex for a real time rendering algorithm! Anyway: Compute the normal n of the triangle. Then compute the plane

问题 I have application created with QT5 and Visual Studio 2013 . I also use QT WebEngine in my application. My application works fine in windows 7 (32 bit) . For some reason i need to run it in windows xp sp3 (32 bit). When i run it, I get the following error: The procedure entry point strnlen could not be located in the dynamic link library msvcrt.dll I press OK several time and it goes away and my QMainWindow will pop out, But its totally BLACK and i see the following errors in debugger. class

问题 I am working on a spatial analysis problem and part of this workflow is to calculate the angle between connected line segments. Each line segment is composed of only two points, and each point has a pair of XY coordinates (Cartesian). Here is the image from GeoGebra. I am always interested in getting a positive angle in 0 to 180 range . However, I get all kind of angles depending on the order of vertices in input line segments. The input data I work with is provided as tuples of coordinates.

问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 6 years ago . I want to get angle between 3 points in JavaScript. If I have points A(x1,y1), B(x2, y2), C(x3, y3) I want to get angle that is formed with lines AB and BC. let A = {x:x1, y:y1}, B = {x:x2, y:y2}, C = {x:x3, y:y3} 回答1: Try this function : /* * Calculates the angle ABC (in radians) * * A first point, ex: {x: 0, y