I am trying to make an animation of the effect of an opening door. Is there any known algortihms for doing this? If not, I need to alter a rectangular div making the right side longer than the left side, and the top and bottom lines connecting the right to left side of the div would be diagonal, and the contents of the div, are stretched proportionally. Is there a way to change the height properties like so, for a div?
You can do it using CSS Transform however it won't support older browsers. Here is a good tutorial for that: http://24ways.org/2010/intro-to-css-3d-transforms/
Your best bet is making an animation using several images and changing them.