Rotation matrix confirmation

relpats_eht · 2005-07-28T10:39:36

I was just wondering if anyone would confirm for me wheather or not the following would be correct code to rotate a 4x4 matrix initialized to [ 1, 0, 0, 0] [ 0, 1, 0, 0] [ 0, 0, 1, 0] [ 0, 0, 0, 1] acording to given x, y, and z rotation values (yes, i know it is the most inefficient code ever written, i just want to know if its correct or not before i remove all the calls to sin and cos) rotMat[0][0] = cos(yrot)*cos(zrot)+sin(yrot)*sin(xrot)*sin(zrot); rotMat[0][1] = cos(yrot)*-sin(zrot)+sin(yrot)*sin(xrot)*cos(zrot); rotMat[0][2] = sin(yrot)*cos(xrot); rotMat[1][0] = cos(xrot)*sin(zrot); rotMat[1][1] = cos(xrot)*cos(zrot); rotMat[1][2] = -sin(xrot); rotMat[2][0] = -sin(yrot)*cos(zrot)+cos(yrot)*sin(xrot)*sin(zrot); rotMat[2][1] = -sin(yrot)*-sin(zrot)+cos(yrot)*sin(xrot)*cos(zrot); rotMat[2][2] = cos(yrot)*cos(xrot); I suspect I did something wrong, as all I know of matrix math I learned in a day over the net almost a year ago, and havent used it since.

NeHe Productions Affiliates

Started by relpats_eht July 12, 2005 04:53 PM

9 comments, last by GameDev.net 19 years, 1 month ago

Anonymous

July 28, 2005 10:39 AM

Well, as I see it, the best way to perform rotation in openGL is using
unit quaternions. From theese quaternions you can create rotation matrices in a simple cookbook manner, and then just use glMultMatrix. This avoids problems such
as gimbal lock etc. google quaternions and you'll find everything you need!