Convert Quaternion rotation to rotation matrix?

by

The following code is based on a quaternion (qw, qx, qy, qz), where the order is based on the Boost quaternions:

boost::math::quaternion<float> quaternion;
float qw = quaternion.R_component_1();
float qx = quaternion.R_component_2();
float qy = quaternion.R_component_3();
float qz = quaternion.R_component_4();

First you have to normalize the quaternion:

const float n = 1.0f/sqrt(qx*qx+qy*qy+qz*qz+qw*qw);
qx *= n;
qy *= n;
qz *= n;
qw *= n;

Then you can create your matrix:

Matrix<float, 4>(
    1.0f - 2.0f*qy*qy - 2.0f*qz*qz, 2.0f*qx*qy - 2.0f*qz*qw, 2.0f*qx*qz + 2.0f*qy*qw, 0.0f,
    2.0f*qx*qy + 2.0f*qz*qw, 1.0f - 2.0f*qx*qx - 2.0f*qz*qz, 2.0f*qy*qz - 2.0f*qx*qw, 0.0f,
    2.0f*qx*qz - 2.0f*qy*qw, 2.0f*qy*qz + 2.0f*qx*qw, 1.0f - 2.0f*qx*qx - 2.0f*qy*qy, 0.0f,
    0.0f, 0.0f, 0.0f, 1.0f);

Depending on your matrix class, you might have to transpose it before passing it to OpenGL.

More Related Contents:

  1. How do I compose a rotation matrix with human readable angles from scratch?
  2. how should i handle (morphing) 4D objects in opengl? [closed]
  3. How to use GLUT/OpenGL to render to a file?
  4. How to implement 2D raycasting light effect in GLSL
  5. Rotating a Group of Vectors
  6. Matrix inverse accuracy
  7. Getting the true z value from the depth buffer
  8. How exactly does OpenGL do perspectively correct linear interpolation?
  9. Interpolating between rotation matrices
  10. Why does OpenGL not support multiple index buffering?
  11. What exactly are eye space coordinates?
  12. What does glLoadIdentity() do in OpenGL?
  13. OpenGL: scale then translate? and how?
  14. Rendering meshes with multiple indices
  15. OpenGL – How to create Order Independent transparency?
  16. OpenGL 3D-raypicking with high poly meshes
  17. What are the Attribute locations for fixed function pipeline in OpenGL 4.0++ core profile?
  18. The purpose of Model View Projection Matrix
  19. Using Quaternions for OpenGL Rotations [duplicate]
  20. What is state-of-the-art for text rendering in OpenGL as of version 4.1? [closed]
  21. Generating a normal map from a height map?
  22. I have an OpenGL Tessellated Sphere and I want to cut a cylindrical hole in it
  23. Edges on polygon outlines not always correct
  24. How to Using the #include in glsl support ARB_shading_language_include
  25. How do you get the modelview and projection matrices in OpenGL?
  26. Multiple textures in GLSL – only one works
  27. GLSL, semaphores?
  28. OpenGL stretched shapes – aspect ratio
  29. Frequency of shader invocations in rendering commands
  30. how to enable vertical sync in opengl?

Leave a Comment