--- name: "SbRotation" section: "3" platform: "linux" package: "coin" version: "1:4.0.10-1" release: "Arch Linux 2026-11-01" platforms: ["linux"] url: "https://new.carta.tech/SbRotation" --- # SbRotation(3) The SbRotation class represents a rotation in 3D space. ## NAME SbRotation - The **SbRotation** class represents a rotation in 3D space. ## SYNOPSIS \#include \ ### Public Member Functions **SbRotation** (void)\ **SbRotation** (const **SbVec3f** &axis, const float radians)\ **SbRotation** (const float q\[4\])\ **SbRotation** (const float q0, const float q1, const float q2, const float q3)\ **SbRotation** (const **SbMatrix** &m)\ **SbRotation** (const **SbVec3f** &rotateFrom, const **SbVec3f** &rotateTo)\ const float \* **getValue** (void) const\ void **getValue** (float &q0, float &q1, float &q2, float &q3) const\ **SbRotation** & **setValue** (const float q0, const float q1, const float q2, const float q3)\ void **getValue** (**SbVec3f** &axis, float &radians) const\ void **getValue** (**SbMatrix** &matrix) const\ **SbRotation** & **invert** (void)\ **SbRotation** **inverse** (void) const\ **SbRotation** & **setValue** (const float q\[4\])\ **SbRotation** & **setValue** (const **SbMatrix** &m)\ **SbRotation** & **setValue** (const **SbVec3f** &axis, const float radians)\ **SbRotation** & **setValue** (const **SbVec3f** &rotateFrom, const **SbVec3f** &rotateTo)\ **SbRotation** & **operator\*=** (const **SbRotation** &q)\ **SbRotation** & **operator\*=** (const float s)\ float **operator\[\]** (int n) const\ returns the n'th quaternion of this rotation SbBool **equals** (const **SbRotation** &r, float tolerance) const\ void **multVec** (const **SbVec3f** &src, **SbVec3f** &dst) const\ void **scaleAngle** (const float scaleFactor)\ **SbString** **toString** () const\ SbBool **fromString** (const **SbString** &str)\ void **print** (FILE \*fp) const\ ### Static Public Member Functions static **SbRotation** **slerp** (const **SbRotation** &rot0, const **SbRotation** &rot1, float t)\ static **SbRotation** **identity** (void)\ ## Detailed Description The **SbRotation** class represents a rotation in 3D space. **SbRotation** is used extensively throughout the Coin library. An **SbRotation** is stored internally as a quaternion for speed and storage reasons, but inquiries can be done to get and set axis and angle values for convenience. Note that there is one *very* common mistake that is easy to make when setting the value of an **SbRotation**, and that is to inadvertently use the wrong **SbRotation** constructor. This example should clarify the problem: ``` SbRotation rotation(0, 0, 1, 1.5707963f); ``` The programmer clearly tries to set a PI/2 rotation around the Z axis, but this will fail, as the **SbRotation** constructor invoked above is the one that takes as arguments the 4 floats of a *quaternion*. What the programmer almost certainly wanted to do was to use the **SbRotation** constructor that takes a rotation vector and a rotation angle, which is invoked like this: ``` SbRotation rotation(SbVec3f(0, 0, 1), 1.5707963f); ``` Another common problem is to set the rotation value to exactly 0.0, while wanting to store just the information about a rotation *angle:* rotations are internally handled as quaternions, and when converting from an angle and a rotation value to a quaternion representation, the information about the angle "gets lost" if there is no actual rotation. **See also** **SbMatrix** ## Constructor & Destructor Documentation ### SbRotation::SbRotation (void ) The default constructor just initializes a valid rotation. The actual value is unspecified, and you should not depend on it. ### SbRotation::SbRotation (const SbVec3f & axis, const float radians) Construct a new **SbRotation** object initialized with the given axis-of-rotation and rotation angle. ### SbRotation::SbRotation (const float q\[4\]) Construct a new **SbRotation** object initialized with the given quaternion components. The array must be ordered as follows: q\[0\] = x, q\[1\] = y, q\[2\] = z and q\[3\] = w, where the quaternion is specified by q = w + xi + yj + zk. ### SbRotation::SbRotation (const float q0, const float q1, const float q2, const float q3) Construct a new **SbRotation** object initialized with the given quaternion components. ### SbRotation::SbRotation (const SbMatrix & m) Construct a new **SbRotation** object initialized with the given rotation matrix. ### SbRotation::SbRotation (const SbVec3f & rotateFrom, const SbVec3f & rotateTo) Construct a rotation which is the minimum rotation necessary to make vector *rotateFrom* point in the direction of vector *rotateTo*. Example: ``` #include #include #include int main(void) { SbVec3f from(10, 0, 0); SbVec3f to(0, 10, 0); SbRotation rot(from, to); SbVec3f axis; float angle; rot.getValue(axis, angle); axis.print(stdout); printf(" angle==%f\n", angle); return 0; } ``` ## Member Function Documentation ### const float \* SbRotation::getValue (void ) const Return pointer to an array with the rotation expressed as four quaternion values. **See also** **setValue()**. ### void SbRotation::getValue (float & q0, float & q1, float & q2, float & q3) const Return the four quaternion components representing the rotation. **See also** **setValue()**. ### SbRotation & SbRotation::setValue (const float q0, const float q1, const float q2, const float q3) Set the rotation. **See also** **getValue()**. ### void SbRotation::getValue (SbVec3f & axis, float & radians) const Return the rotation in the form of an axis-of-rotation and a rotation angle. **See also** **setValue()**. ### void SbRotation::getValue (SbMatrix & matrix) const Return this rotation in the form of a matrix. **See also** **setValue()**. ### SbRotation & SbRotation::invert (void ) Invert the rotation. Returns reference to self. **See also** **inverse()** ### SbRotation SbRotation::inverse (void ) const Non-destructively inverses the rotation and returns the result. **See also** **invert()** ### SbRotation & SbRotation::setValue (const float q\[4\]) Reset the rotation by the four quaternions in the array. **See also** **getValue()**. ### SbRotation & SbRotation::setValue (const SbMatrix & m) Set the rotation from the components of the given matrix. Returns reference to self. **See also** **getValue()**. ### SbRotation & SbRotation::setValue (const SbVec3f & axis, const float radians) Reset rotation with the given axis-of-rotation and rotation angle. Returns reference to self. Make sure *axis* is not the null vector when calling this method. **See also** **getValue()**. ### SbRotation & SbRotation::setValue (const SbVec3f & rotateFrom, const SbVec3f & rotateTo) Construct a rotation which is the minimum rotation necessary to make vector *rotateFrom* point in the direction of vector *rotateTo*. Returns reference to self. See **SbRotation** constructor with corresponding input arguments for a simple code example. **See also** **getValue()**. ### SbRotation & SbRotation::operator\*= (const SbRotation & q) Multiplies the quaternions. Note that order is important when combining quaternions with the multiplication operator. ### SbRotation & SbRotation::operator\*= (const float s) Multiplies components of quaternion with scalar value *s*. Returns reference to self. ### SbBool SbRotation::equals (const SbRotation & r, float tolerance) const Check the internal quaternion representation vectors for equality within the given tolerance. ### void SbRotation::multVec (const SbVec3f & src, SbVec3f & dst) const Rotate the *src* vector and put the result in *dst*. It is safe to let src and dst be the same **SbVec3f** instance. ### void SbRotation::scaleAngle (const float scaleFactor) Scale the angle of rotation by *scaleFactor*. ### SbRotation slerp (const SbRotation & rot0, const SbRotation & rot1, float t) \[static\] Interpolates along the shortest path between the two rotation positions (from *rot0* to *rot1*). Returns the **SbRotation** which will rotate *rot0* the given part *t* of the spherical distance towards *rot1*, where *t=0* will yield *rot0* and *t=1* will yield *rot1*. *t* should be in the interval \[0, 1\]. ### SbRotation SbRotation::identity (void ) \[static\] Returns an identity rotation. ### SbString SbRotation::toString () const Return a string representation of this object ### SbBool SbRotation::fromString (const SbString & str) Convert from a string representation, return whether this is a valid conversion ### void SbRotation::print (FILE \* fp) const Dump the state of this object to the *fp* file stream. Only works in debug version of library, method does nothing in an optimized build. ## Author Generated automatically by Doxygen for Coin from the source code.