jlGauthier.

http://www.jlgauthier.com/blogSup/stick/edit2/bin-release/StickEdit1.html

Moving along. I was hoping things would go fast tonight but calculating where a vertex should go to based on the x,y of a view port proved to be a lot of code.

Rendering a point in 3d means

1. place the point in scene space (points are stored initially in figure space)
2. translate its position to camera space (relitive to the eye of the camera)
3. rotate its position relative to the eye of the camera’s view direction (the angle between the camera eye and the camera target)
4. translate the position again into view space (if your render region is 400 by 400 you need to move things 200 pixels right and down)
5. scale the final xy coordinates based on the z axis and your perspective multiplier

And that is what gets rendered in the view port… so moving a point in a view port means going through all of those steps backwards to calculate what your really doing to the vertex. Talk about fun.

The next step is easy, allow export and import of figures. But after that its going to get hard again because animation means adding state to the figures, which could lead to some refactoring on the rendering side of things and a lot more math.