quaternions

Wiimote orientation as a 3D vector

由 旧时模样 提交于 2019-12-07 21:04:34
问题 I wonder if it is possible, as the Wiimote has 3 accelerometers, to convert the accelerometers readings to a 3D vector. I know the trick to extract pitch/roll, but it only uses the X and Z accelerometers, and has the gimbal lock problem. What I would like is a full 3D vector, that can be converted to a quaternion rotation representation. 回答1: Thinking about it further, the accelerometers values are the components of the vector I was looking for... You only have to express the shortest arc

Gyroscope with compass help needed

由 ↘锁芯ラ 提交于 2019-12-07 17:03:50
问题 I need to have a game object point north AND I want to combine this with gyro.attitude input. I have tried, unsuccessfully, to do this in one step. That is, I couldn't make any gyro script, which I found on the net, work with the additional requirement of always pointing north. Trust me, I have tried every script I could find on the subject. I deduced that it's impossible and probably was stupid to think it could be done; at least not this way (i.e. all-in-one). I guess you could say I

Properly normalizing a dual quaternion

由 百般思念 提交于 2019-12-07 12:59:18
问题 I'm having trouble with dual quaternions, and I believe it's because they're not properly normalized. A, B and A' are dual quaternions where the latter is conjugated. When doing this: Q = A * B * A' I should theoretically always end up with Q = B if A and B are properly normalized. But in some cases, I don't, and it's completely messing up my whole skeletal hierarchy. Many pages show that the norm of a dual quaternion is ||Q|| = sqrt(QQ'), but that means taking the square root of a dual

Smooth rotation with quaternions

由 前提是你 提交于 2019-12-07 05:21:44
问题 Quaternion can describe not only rotation, but also an orientation, i.e. rotation from initial (zero) position. I was wishing to model smooth rotation from one orientation to another. I calculated start orientation startOrientation and end orientation endOrientation and was wishing to describe intermediate orientations as startOrientation*(1-argument) + endOrientation*argument while argument changes from 0 to 1 . The code for monkey engine update function is follows: @Override public void

Find final world coordinates from model matrix or quaternion

由 不打扰是莪最后的温柔 提交于 2019-12-06 17:05:49
问题 I am displaying an object in OpenGL using a model matrix for the object, which I build from my pre-stored object location AND a quaternion applied to the rotation. I need to find the final cartesian coordinates in 3D of my object AFTER the rotations and transformations applied (the coordinates that the object appears at on the screen). How can I get the plain coordinates? 回答1: If I understand correctly, you have an object; if you rendered it without applying any transformation, its center

Direction vector to a rotation (three.js)

由 半腔热情 提交于 2019-12-06 16:13:17
I'm attempting rotate an arrow on the surface of a planet to face the direction it is traveling. I can get the direction vector and the up vector from the surface normal. How would I go about turning this into a quaternion for my arrows rotation. I'm using three.js so any suggested methods they provided that I can use would be useful. Cheers. The information I have so far. var upVector = new THREE.Vector3(); upVector.subVectors( new THREE.Vector3(0,0,0), lastVec ); var dirVector = new THREE.Vector3(); upVector.subVectors( lastVec, destVec ); var sideVector = new THREE.Vector3(); sideVector

Quaternion from two vector pairs

由 自作多情 提交于 2019-12-06 15:40:40
I have two vector pairs (before and after rotation). before rotation: [x1,y1,z1] [x2,y2,z2] after rotation: [x1',y1',z1'] [x2',y2',z2'] How to create a quaternion representing this rotation? In most cases there is no rotation which transforms 2 vectors into 2 other vectors. Here is a simple way to visualize why: a rotation does not change the angle between vectors. If the angle between the 2 vectors before the rotation is different from the angle between the 2 vectors after the rotation, then there is no rotation which meets your criteria. This said there may be an optimal quaternion with an

Add offset to DeviceOrientationControls in three.js

由 試著忘記壹切 提交于 2019-12-06 14:55:58
I'm trying to add an offset to the camera after deviceControls.update(); command. I used DeviceOrientationControls as shown in this first example. The offset will be the result of a drag gesture, as presents in this example. When I multiply the 2 quaternions (I have tried a x b and b x a), the final result is not correct. Here is my operation : const m1 = new THREE.Matrix4(); m1.lookAt(new THREE.Vector3(), camera.target, THREE.Object3D.DefaultUp.clone()); const quater = new THREE.Quaternion(); quater.setFromRotationMatrix(m1); const finalQuater = new THREE.Quaternion(); finalQuater

Controling OpenSceneGraph camera with Cartesian coordinates and Euler angles

由 巧了我就是萌 提交于 2019-12-06 12:26:13
问题 I am attempting to control an osg::Camera with Cartesian coordinates (X, Y, Z) and Euler angles (Yaw, Pitch, Roll) that I read in from file. Part 1 For some reason setting my roll will cause the camera to rotate around the z-axis and not the y-axis as expected. The following is the previously written camera manipulator that I am feeding my positional data to. class EulerManipulator : public osgGA::CameraManipulator { public: EulerManipulator(osg::ref_ptr<osg::View> x) : view(x), camView(new

Wiimote orientation as a 3D vector

由 泪湿孤枕 提交于 2019-12-06 11:34:06
I wonder if it is possible, as the Wiimote has 3 accelerometers, to convert the accelerometers readings to a 3D vector. I know the trick to extract pitch/roll, but it only uses the X and Z accelerometers, and has the gimbal lock problem. What I would like is a full 3D vector, that can be converted to a quaternion rotation representation. Thinking about it further, the accelerometers values are the components of the vector I was looking for... You only have to express the shortest arc between a reference vector and this vector as a quaternion. For example, if accel is a (normalized) vector
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