The Mill sends Massive agents into battle for Merlin

The Massive Combat Sword agent saw plenty of action recently in the BBC Merlin TV series. Seen in multiple episodes of Merlin, The Mill modified the off-the-shelf agent to create epic shots of up to 40,000 agents. In some of the shots two armies of 4000 to 5000 troops collide in battle. According to The Mill regarding a shot in Season 3 Episode 2 "One of the most challenging shots, here the two armies finally collide. The camera is static and the shot relatively close, so it really shows off the automatic combat behaviour of the sword/shield agent. We used a similar approach of terrain colouring, lanes, flow field and invisible collider agents to guide the densely packed formation through the tight gates and boundaries, then to split to two frontlines.... Once the agents were near enough to each other all we had to do was let them do their thing and hack eachother to pieces." The Mill showing once again that epic film scale visual effects can be achieved for television production.

Ed Hick talks us through some of the shots that he worked on for Season 3 below.

Big valley shot of the Cenred army through a crystal

Merlin season 3 episode 1

"I think this had something like 40,000 agents in it, stretching off into the horizon. In these marching shots we used an optimised version of the sword agent, turning off vision and deleting combat modules. With a few IK arm offset controls we made spear and flag agents from the sword shield agent. This was broken into about 10 pieces for parallel simulation."

Merlin season 3 episode 2

"For this shot we used approach as shot 1."

"And also for this shot we used approach as shot 1."

"This shot contains about 30,000 agents, and includes a row of camelot troops on the battlements, a little closer than we'd normally show massive charcters, but they fit in nicely, and highlight the comparative size of the armies."

"This is a nighttime shot, roughly same layout as the shot from the battlements."

"Same as above, with agents set to charge towards the castle."

"A relatively close up street shot. The challenge here was to satisfy the goals of remaining fast, together, fill the space and not intersect each other or the walls. With a combination of terrain colour, lanes, flow, sound rules and invisible collider agents, which all acted on agent offset channels, I was able to get the agents to satisfy each criteria and convincingly charge the barricade."

Merlin season 3 episode 12

"Here the army is used as a set extension, continuing on from the back of a live action plate. This shot contains about 20-30 thousand troops."

"In this shot we see around 6k agents walking around a bend in a dried up riverbed. In order to get agent lights without using renderman we used alpha cards for the direct flame, then a spawned agent attached to the torch to act as the light location and write the light's attributes into apf files. Later a python script converted the agents to point lights in the mi archive file before rendering."

"Here there are 20,000 to 30,000 agents walking through a valley, in a similar way to the army in episode 2."

"Here is a similar setup as that in shot 10. One thing to note is that the placement and rendering of the tents was also taken care of in massive, which made it easy to setup avoidance for the few agents milling around the campsite."

Merlin season 3 episode 2

"One of the most challenging shots, here the two armies finally collide. The camera is static and the shot relatively close, so it really shows off the automatic combat behaviour of the sword/shield agent. We used a similar approach of terrain colouring, lanes, flow field and invisible collider agents to guide the densely packed formation through the tight gates and boundaries, then to split to two frontlines (one is off screen to the top left). Once the agents were near enough to each other all we had to do was let them do their thing and hack eachother to pieces. Death and dynamics were switched off in this case as merlin is a show for kids. Roughly 4-5 thousand agents on screen."

"In this continuation of the previous shot the defending army is pushing back the intruders to the outer gate. A few more clever brain tricks getting the camelot troops to flock around the entrance and some automatic fighting in the gateway really sold this shot nicely."