## SIQuaternion.Mul

### Description

Multiplies the quaternion q1 by the quaternion q2 and stores the result in this quaternion: this = q1 . q2
When used in the context of rotation this operation has the effect of adding two rotations.

### C# Syntax

    SIQuaternion.Mul( SIQuaternion in_pQuat1, SIQuaternion in_pQuat2 );

### Scripting Syntax

    SIQuaternion.Mul( q1, q2 );

### Parameters

Parameter | Type | Description
--- | --- | ---
q1 | SIQuaternion | quaternion operand
q2 | SIQuaternion | quaternion operand

### Examples

#### VBScript Example

    dim q1, q2, q3

    ' Create Quaternions.

    set q1 = XSIMath.CreateQuaternion(1.0, 1.0, 2.0, 3.0)

    set q2 = XSIMath.CreateQuaternion(1.0, 4.0, 5.0, 6.0)

    set q3 = XSIMath.CreateQuaternion

    'q3 = q1 . q2

    q3.Mul q1, q2

    Application.LogMessage "q3 : " & q3.W & "," & q3.X & "," & q3.Y & "," & q3.Z

    'Mul operation is non-commutative

    q3.Mul q2, q1

    Application.LogMessage "q3 : " & q3.W & "," & q3.X & "," & q3.Y & "," & q3.Z

    'Output

    'INFO : q3 : -31,2,13,6

    'INFO : q3 : -31,8,1,12

### See Also

SIQuaternion.MulInPlace SIVector3 SIMatrix3 SIMatrix4 SIRotation SITransformation SIQuaternion