# Blog

## What is a quaternion OpenGL? ## What is a quaternion OpenGL?

A quaternion is an element of a 4 dimensional vector-space. ... Every unit quaternion represents a 3D rotation, and every 3D rotation has two unit quaternion representations. Unit quaternions are a way to compactly represent 3D rotations while avoiding singularities or discontinuities (e.g. gimbal lock).

## What is quaternion used for?

Quaternions are vital for the control systems that guide aircraft and rockets. Let us think of an aircraft in flight. Changes in its orientation can be given by three rotations known as pitch, roll and yaw, represented by three arrays of numbers called matrices.Oct 4, 2018

## What is XYZW quaternion?

Quaternions. A quaternion is a set of 4 numbers, [x y z w], which represents rotations the following way: // RotationAngle is in radians x = RotationAxis. x * sin(RotationAngle / 2) y = RotationAxis. y * sin(RotationAngle / 2) z = RotationAxis.

## What is quaternion identity in unity?

Description. The identity rotation (Read Only). This quaternion corresponds to "no rotation" - the object is perfectly aligned with the world or parent axes. public class Example : MonoBehaviour { void Start() { transform.rotation = Quaternion.identity; } }  ### How do you use quaternions?

With quaternions, it's as simple as multiplication. Typically you will take the orientation you have (as a quaternion) and just multiply by the rotation (another quaternion) you want to apply.May 15, 2015

### Do quaternions have units?

Unit quaternions, known as versors, provide a convenient mathematical notation for representing spatial orientations and rotations of elements in three dimensional space.

### What is a quaternion in math?

In mathematics, the quaternion number system extends the complex numbers. ... Hamilton defined a quaternion as the quotient of two directed lines in a three-dimensional space, or, equivalently, as the quotient of two vectors. Multiplication of quaternions is noncommutative.

### Should I use quaternions?

Quaternions are very efficient for analyzing situations where rotations in R3 are involved. A quaternion is a 4-tuple, which is a more concise representation than a rotation matrix. Its geo- metric meaning is also more obvious as the rotation axis and angle can be trivially recovered.Sep 10, 2013

### Why are quaternions better?

Because they have a number of appealing properties. First one can nicely interpolate them, which is important if one is animating rotating things, like the limbs around a joint. With a quaternion it is just scalar multiplication and normalization.Jan 19, 2012

### Why are quaternions used for rotation?

A rotation of Euler angles is represented as a matrix of trigonometric functions of the angles. ... While quaternions are much less intuitive than angles, rotations defined by quaternions can be computed more efficiently and with more stability, and therefore are widely used.

### What is q8 group?

In group theory, the quaternion group Q8 (sometimes just denoted by Q) is a non-abelian group of order eight, isomorphic to the eight-element subset of the quaternions under multiplication. It is given by the group presentation. where e is the identity element and e commutes with the other elements of the group.

### What does quaternion Euler do?

Quaternion. Euler generates a Quaternion that represents the orientation or relative rotation specified by the Euler/Tait-Bryan angles you provide as inputs. Transform. Rotate rotates a transform by an incremental amount, specified by the Euler/Tait-Bryan angles you provide as inputs.Apr 30, 2018

### Why do we need to convert quaternions in OpenGL?

• You have to convert them to get a human-readable representation (Euler angles) or something OpenGL can understand (Matrix). Smooth interpolation between quaternions is complicated by the fact that each 3D rotation has two representations. Quaternions are neat because the unit quaternions are a double-cover for the set of 3D rotations.

### How do I rotate a quaternion in GLSL?

• Convert your quaternion to a rotation matrix, and use it in the Model Matrix. Your vertices will be rotated as usual, with the MVP matrix. In some cases, you might actually want to use quaternions in GLSL, for instance if you do skeletal animation on the GPU.

### How do you change the orientation of a quaternion?

• When you decide to apply a rotation to it (of some angle by some axis), you construct a quaternion that represents that rotation by an angle around that axis. Then you right-multiply that quaternion with the current orientation quaternion, producing a new current orientation.

### What are the advantages of Quaternions over Euler angles?

• Quaternions have some advantages over other representations of rotations. Quaternions don't suffer from gimbal lock, unlike Euler angles. They can be represented as 4 numbers, in contrast to the 9 numbers of a rotations matrix. The conversion to and from axis/angle representation is trivial.

### Why do we need to convert quaternions in OpenGL?Why do we need to convert quaternions in OpenGL?

You have to convert them to get a human-readable representation (Euler angles) or something OpenGL can understand (Matrix). Smooth interpolation between quaternions is complicated by the fact that each 3D rotation has two representations. Quaternions are neat because the unit quaternions are a double-cover for the set of 3D rotations.

### How do I rotate a quaternion in GLSL?How do I rotate a quaternion in GLSL?

Convert your quaternion to a rotation matrix, and use it in the Model Matrix. Your vertices will be rotated as usual, with the MVP matrix. In some cases, you might actually want to use quaternions in GLSL, for instance if you do skeletal animation on the GPU.

### What are the advantages of Quaternions over Euler angles?What are the advantages of Quaternions over Euler angles?

Quaternions have some advantages over other representations of rotations. Quaternions don't suffer from gimbal lock, unlike Euler angles. They can be represented as 4 numbers, in contrast to the 9 numbers of a rotations matrix. The conversion to and from axis/angle representation is trivial.

### What is a quaternion in math?What is a quaternion in math?

A quaternion is a set of 4 numbers, [x y z w], which represents rotations the following way: RotationAxis is, as its name implies, the axis around which you want to make your rotation. RotationAngle is the angle of rotation around this axis.