Progressive rendering & movable camera

[Alxiice]

• be able to move the camera with a "trackball" system
• to do that we also need progressive rendering (to avoid lag) :
  • buckets
  • multithreading

It will probably add some other things in the process :

• matrix operations
• better iterator on camera rays (group by bucket + several modes possible : spiral, top to bottom, right to left, etc)
• maybe also think about transformations applied to objects : extend ObjectParams to have a transformation matrix

[Alxiice]

References :

• https://github.com/Alxiice/projets-cours/blob/master/Graphique3D/TP6/transform.py#L177
• https://github.com/Alxiice/projets-cours/blob/master/Graphique3D/TP6/viewer.py#L256

[Alxiice]

• Rendering bucket by bucket (top to bottom)
• Rendering buckets in separate threads
• Spiral mode for bucket
• Integrate bucket size and mode to the UI
• Implement changing the window/render size
• Implement trackball