Tag: rotation

Apr

Image rotation with bilinear interpolation and no clipping

I wrote an article on image rotation with bilinear interpolation to calculate the pixel information. Commenter Jahn wanted to know if the resulting image could be obtained without clipping. I replied with the required code changes (it was fairly minimal), then I thought it might be useful to you too. The code was cleaned up […]

Mar

Stationary camera, moving scene

Previously, we talked about revolving the entire 3D scene about the camera, and also the problem of the camera looking directly downwards. Today, we’ll look at the mechanics of implementing that stationary camera (it ain’t pretty). There are 2 transformations to take care of: translation and rotation. Translation takes care of the distance between the […]

Sep

Rotating a matrix cannot be done with matrix multiplication

Note that this is different from rotation matrices in our previous discussion on transformation matrices. We were rotating (3D) objects and vertices (points) then. We’re talking about rotating a matrix here. I read this article by Raymond Chen discussing the rotation of a 2 dimensional array (which is equivalent to a matrix in our case). […]

Sep

Cartesian coordinates and transformation matrices

If you’re doing any work in 3D, you will need to know about the Cartesian coordinate system and transformation matrices. Cartesian coordinates are typically used to represent the world in 3D programming. Transformation matrices are matrices representing operations on 3D points and objects. The typical operations are translation, rotation, scaling. 2 dimensional Cartesian coordinates You […]