euler-angles

问题 I'm trying to implement a functionality that can convert an Euler angle into an Quaternion and back "YXZ"-convention using Eigen. Later this should be used to let the user give you Euler angles and rotate around as Quaternion and convert Back for the user. In fact i am realy bad at math but tried my best. I have no Idea if this matrices are correct or anything. The code Works, but my results are way to off, i suppose. Any idea where i take the wrong turn? This is what my Quat.cpp looks like:

问题 I'm trying to get a the Euler angle of a Face that is detected by FaceDetector. Here is what I use to output to Logcat: Log.v("debug", " X: " + face.pose(Face.EULER_X) + " Y: " + face.pose(Face.EULER_Y) + " Z: " + face.pose(Face.EULER_Z) ); But it always returns 0.0 for all three, no matter what angle the face is at. Any ideas why? 回答1: Yeah the FaceDetector from API 1 never returns a pose angle. You can look at the source code to verify. The newer FaceDetectionListener from API 14 will

问题 I have a nice quaternion to euler equation that is sometimes returning a non-intuitive set of angles. For example: Pitch: 129 Yaw: -85 Roll: 126 I would like to programatically find alternate rotations such that Pitch and Roll are between -90 and 90. Yaw can be 0 to 360. [EDIT] Pitch is constrained to -90 to +90 and Roll is constrained to -180 to +180. 回答1: Basically, you want to prevent the orientation to go beyond the pole. It is very easy to do that: First, check if pitch is beyond the

问题 Firstly, I have done much googling and checking other stackoverflow posts about this, but cannot get a working reply or a snippet of working code. Maths is not my strength. I need to have a routine that takes a camera point (CX,CY,CZ) and rotate it about a lookat point (LX,LY,LZ) by three rotation angles (RX,RY,RZ). Using euler rotations leads to gimbal lock in some cases which I need to avoid. So I heard about using quaternions. I found this to convert the rotations into a quaternion http:/

问题 I hope this is the proper location to ask this question which is the same as this one, but expressed as pure math instead of graphically (at least I hope I translated the problem to math correctly). Considering: two vectors that are orthogonal: Up (ux, uy, uz) and Look (lx, ly, lz) a plane P which is perpendicular to Look (hence including Up) Y1 which is the projection of Y (vertical axis) along Look onto P Question: what is the value of the angle between Y1 and Up? As mathematicians will

问题 I've been trying to figure out the difference between these, and why ToEulerXYZ does not get the right rotation. Using MathGeoLib: axisX: x 0.80878228 float y -0.58810818 float z 0.00000000 float axisY: x 0.58811820 float y 0.80877501 float z 0.00000000 float axisZ: x 0.00000000 float y 0.00000000 float z 1.0000000 float Code: Quat aQ = Quat::RotateAxisAngle(axisX, DegToRad(30)) * Quat::RotateAxisAngle(axisY, DegToRad(60)) * Quat::RotateAxisAngle(axisZ, DegToRad(40)); float3 eulerAnglesA = aQ

问题 When transforming a quaternion to Euler Angles, usually there has to be a order in which the axes are rotated, like in this visualization. How does it work for libgdx? The Quaternion class has the functions getRoll(): Math.asin(MathUtils.clamp(2f * (w*x - z * y), -1f, 1f)) : (float)pole * MathUtils.PI * 0.5f;` getPitch(): Math.asin(MathUtils.clamp(2f * (w*x - z * y), -1f, 1f)) : (float)pole * MathUtils.PI * 0.5f;` getYaw(): ` MathUtils.atan2(2f * (y * w + x * z), 1f - 2f * (y * y + x * x)) :

问题 Is it possible to convert the yaw Euler angle got from the Bullet physics engine using btTransform trans; trans.getBasis().getEulerYPR(rx, ry, rz); into the range [0 , 360]. Otherwise for a 360 deg rotation I get the Euler angle varying from 0->90->0-> -90 -> 0 but I want from 0->90->180->270->0 My graphics API only accepts rotation angles in the range of 0 to 360 Well, the 0->90->0-> -90 was the pitch value. Here is the code I use now : trans.getBasis().getEulerYPR(yaw, pitch, roll); y1 =

问题 So I searched on the net and I'm having some problems imagining how the gimbal-lock occurs. According to what i saw, it occurs when 2 or more axes align losing a degree of freedom but I can't imagine how will the axes even begin to align? I mean, when i rotate an object around x-axis (for example) doesn't the y and z axes rotate with the X-axis to remain perpendicular? How are they gonna align? Similarly whenever i rotate around Y or Z axis the other 2 axis rotate together and remain

问题 I'm working on some simple 3d graphics in OpenGL (java LWGJL), and I'm trying to figure out how to convert yaw, pitch and roll to the x, y and z components of my movement Vector. I know how to do this with just pitch and yaw (as explained here), but I haven't found anything the explains how to integrate roll into this formula. I am aware that yaw and pitch are all that is needed to define a vector in 3d space, but I also need roll in this instance. I have keys bound to different movements