Paul Giamatti as King John and Vladimir Kulich as the mercenary captain, Tiberious, try unsuccesfully to reason with the rebels holding the castle.
In the background can be seen the virtual construction of the King's camp. All the soldiers were shot separately on greenscreen.
We ultimately produced over 250 visual effects shots for this film. Since it was all in an historical context, the shots are "invisible" for the most part. So to see them:
Roll Over the Images for BEFORE and AFTERS
A shot of the trebuchet firing missiles at the castle. The Castle had to be extended every time we saw it. Also the river Medway, which actually runs alongside the real Rochester castle didn't exist on our location. We shot river elements and composited them into every shot where we saw the river, along with a CG bridge.
The missiles were foam up to the point where they left the sling, then CG took over. We used RocSim, a ballistic rocketry simulation software to develop accurate simulations for the flying projectiles.
The destruction to Rochester Castle had to be created with miniature photography. In this shot, a miniature pile of rubble and the exposed edges of the stone were shot in 1/6 scale. These were blended with a real pile of actual rubble in the plate. Additional mercenaries were shot climbing up a greenscreen "pile" and these were placed in into the shot. Finally the deep interior of the castle was added with a matte painting.
The siege tower was actually not able to roll more than a few feet, and even then only with a piece of heavy equipment pushing it, so we had to use green screens to visually place it farther away from the castle than it actually was. All the background soldiers here are added from greenscreen elements shot later.
Many shots had to be constructed from still photographs of the castle.
The french army had to be constructed from only about 15 individuals and half a dozen horses. For this shot we had three passes of foreground soldiers coming over a ridge, pulling a key off the sky. The rest of the soldiers were shot as elements on a green screen stage and the background is a matte painting.
The King's Camp was a major challenge. Almost all of the shots looking in these direction (and there are a lot of them) were constructed from still photos of the camp. Only a few tents were actually there, and only one trebuchet. The rest of the soldiers were shot on greenscreen and compositied in. We didn't need to resort to any CG soldiers, because of the very complete library of soldier elements that we shot. These shots were then brought into Nuke to create 3D camera moves that could pan all the way onto the castle.
We built one full size working trebuchet that could fire a large foam bolder several hundred feet... though with a little tuning, we probably could have turned this prop into a fully functional lethal weapon. Instead of moving to trebuchet to get different perspectives on it, we moved the camera the same distance that we visually wanted them to appear.