February 17, 2006

Prey Weekly Development Update #6

Prey is the first product in which Human Head has used motion capture. In the past, we've always hand-animated our characters for a few different reasons - we know the time and effort it takes to animate a given character, we know what the results will look like, and because we needed the ability to easily tweak the animations. In Rune, the attack animations required a lot of tuning and tweaking throughout development. Now, in Prey - we decided during development to try using motion capture on our human characters, Tommy, Jen, Tommy's Grandfather, and various human NPCs that Tommy encounters on the Sphere.

Since we had never done motion capture before, honestly, we flew a bit blind at first. We first developed a comprehensive list of all animations in the game that would benefit from motion capture, this included such things as:

  • Player animations (carrying each weapon, running, crouching, etc)
  • Human NPC animations (idles, walks, runs, attacks, etc)
  • Humanoid Creature animations (idles, attacks, runs, pains, etc)
  • Experimental animations - ones that we felt might be better to hand animate, but wanted to try motion capture to see how that would work (a character floating inside of a tank is an example)
  • All cinematic animations of characters walking from a specific point to a point, body language and gestures, etc.

Jeff DeWitt, Lead Animator on Prey, developed this comprehensive list from the creature AI list and from the script.

A small group of us then sat down and went over this list, expanding it as necessary by discussing what was needed, and even acting out parts of the script to get a better feel for what we would need.

Finally, with list in hand, Jeff and I headed down to Red Eye Studios, in Chicago for the actual mocap session.

Here's a shot of the overall mocap studio. We're reviewing a previous animation at this point, so Geno (the actor who plays all the male character roles) is standing in the center waiting for direction. You'll notice that his suit contains a lot of reflective balls, each of these are recorded by the motion capture system to translate his body position into animation data.

The motion capture only lasted two days - the first day consisted of all of the female motion capture, and a few scenes where we needed multiple actors interacting with each other.

Grace McPhillips performed the role of all the female characters in the game - she did a great job despite the abuse she took (at one point, we hoisted her up in the air - for the floating in tank section I mentioned before) and then motion captured her while she was dropped to the ground. Yes, there was a mat there to protect her.

The next day, Geno Kett showed up to perform the male character roles. Like Grace, he did a great job acting out what we wanted and he took his abuse really well. One of the more interesting parts was getting the runs for multiplayer - in MP the player actually runs at an unrealistically high rate (the MP is designed for fun action, not 100% realism). We marked out the run speed on the floor in chalk and did take after take until Geno got as close as possible to the speed we wanted.

Speaking of chalk: We learned a pretty valuable lesson (one that other people who have done mocap before will say sounds like common sense): plan out your animations around foot placement and make sure you chalk the foot placement right away. A few times we would be a few animations into a sequence and realize that the foot placement had moved - and then would have to go back and reshoot the previous animations again to guarantee that the actor’s feet had not moved.

Here Geno is acting out the role of a scared human trapped on the Sphere cowering for his life. Jeff DeWitt of Human Head stands in the background directing him.

If we use motion capture again, we’ll definitely plan things a bit more around foot placement, so that we record a series of animations in a row before the actor has to move their feet.

For cinematic purposes, we brought along the entire dialog to play for the motion capture actors. In directing these sequences, we explained the situation, and the general mood of the scene. Then, we played the audio of the dialog a few times so they were comfortable with it, then they simply acted along with the dialog. Typically it took a few takes but eventually we hit upon something that worked.

In the end, the motion capture has been a mixed issue - some sequences worked out really great when motion captured and definitely saved some time. Other sequences turned out okay and are currently undergoing in-house tweaking to get rid of some motion capture artifacts. A few animations probably shouldn’t have been motion captured in the first place, so they’ve been thrown out and replaced with hand animation.

Will we use motion capture in the future? Yes, we will - but, like most aspects of development, it’s a tool that can be used in certain places for certain things. Now having a better knowledge of the overall system and the planning required for it, we certainly will be more efficient next time.

Next week on the weekly update, we’ll be answering some of the questions that were emailed over this past week on Prey. And in a couple of weeks, we’ll have a special update focusing on the Xbox 360 version, written by the studio head of Venom Games. Venom are responsible for the 360 version of Prey. Should be great stuff!

Chris Rhinehart - Prey Project Lead
Human Head Studios

At one point the motion capture system's hard drive was full. So we had a few minutes while they cleared out some space. I talked Jeff into Max Payne'ing onto one of the stunt mats. Six jumps (and a bruised shoulder) later, we snapped this fine shot.

Click the screenshot to watch Prey in action on the videos page!

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Posted by Joe Siegler on February 17, 2006 at 2:53 PM | Permalink
News Categories: Prey | Weekly Updates