geometry tranform problem
Posted on 2004-09-16
My linear algreba's a little shaky, hence the question...
I have a non axis aligned box parameterised something like:
To draw this thing I apply transformations like this:
extents -> eulers -> center
ie. scale -> rotate -> translate
I want to recalculate the translate when I update the scale to give the same tranformation such that a particular side of the box remains in the same position.
The box is editable by the user who can pull the edges to scale the box, or use a widget to rotate the box. With zero rotations the box behaves ok, I calculate the center to compensate for the adjusted edge. However when the box is rotated this calculation is not so simple I cannot get the same behaivour, the box moves around.
The end result needs to be a 4x4 matrix that represents the tranformation so there maybe another representation would be better.
Any help really appreciated.