Awesome kit, brand new space!

We were moving campus, and had the opportinity to design a new space – not something that happens very often!

We were lucky to have had a brand new set of Vicon T-40s cameras, so kit wise we’re doing well, but we knew we could do better.

The main concern was how we mounted the cameras – the existing stage has them attached to the walls, but whenever a door is banged or someone bumps into a wall, then the cameras shake. Not great.

The old stage

Research time!

There’s plenty of large stages out there, so why not learn a few things from them first?

What other people are doing

There were a few common elements across the stages I could find:

  • Trussing to hang the existing cameras off, and room to expand in the future
  • Dark painted walls for facial capture
  • Blinds to block light, mainly IR
  • Soft flooring
  • Landing and crash mats

There was a fair amount more to learn that I couldn’t get from photos and videos online, so I joined up to The Mocap Vault’s Annual summit hosted at centroid in London, a two day weekend with all access to a mocap stage – perfect opportinity to talk someone’s ear off and learn everything I needed to know!

UK Motion Capture Summit with Mocap Vaults at Centroid

Aaaaand the shopping list got bigger:

  • Reference video – it’s HUGELY important, and from multiple views
  • Lobo scaffolding lets you capture motions that just aren’t possible using only the floor
  • Live previs is important for checking the use of space and planning moves
  • Having screens for the reference video and previs lets people watch the action away from the stage
  • The suits are indiviually coloured and have stripes to help clean up data against the reference video
  • Timecode is essential for matching audio, mocap, previs and reference footage together – sub frame accurate preferably!

Some of these things we can do right away, but others would have to wait, or prototyped first.

The scaffolding was reasonably simple to sort out, we used GlobalTruss’ online designer to plan out the parts. It’s cheap, easily procured from thomann.de and rediculously strong. Perfect. My colleague Aaron from music tech had worked with stage kit like his before, so with his help we did the caclulations for the trussing, and well, we can hang a landrover defender from the middle just fine. I think a few cameras will cope!

Global Truss Interactive Designer

None of us had built trussing before, so we did a test build on the ground of the top section. It’s a lot lighter than you’d expect. We were still surrounded by kit waiting to be re-homed in the new labs, so we couldn’t finish up until we’d cleared it all out.

Building the Trussing

The flooring came next – we went for an interlocking Judo floor from SoftFloor, which may or may not be the same place Centroid acquired theirs…

The floor is great, and you can drop to your knees or fall over without hurting yourself, but repeated falls or anything more “athletic” would need better mats. For these we went to continental sports for some gymnastic mats. On advice of our friends in sports science, we went with a set of 1 x 2m wrestling mats with velcro edges and a couple of larger landing mats.

The wrestling mats are absorbent enough that you could repeat a “fall to your knees” movement over a number of times without injury, and can be arranged in a long line, or a larger central area if needed.

The larger landing mats were in honestly firmer than we expected, but whatever cost of performer comfort was well recovered in the quality of the data captured. Where our older “crash” mats were super absorbent and made legs and body parts bounce back, the newer landing mates were wholly unforgiving and stopped you in your tracks. The falls were more convincing, but still safe for our performers!

Out with the old...

Hardware time! I called in some favours with our digital services deptment to have a raid of their recycling pile, and what to find but two plasma TVs being decomissioned from the library! Score!

Now these things are insanely heavy, but look amaxing installed on the trussing with their industrial vibes! People and a lot of rope later, and both of them are hung up on the trussing.

Next up was a noise isolating cabinet courtesy of animation. They used it for their BOXX renderfarm before I made all the idle labs into one. In it we’ve got top to bottom:

  • A Brocade 10gb switch for the room network (10G ports on the rear option cards)
  • THe Vicon Giganet for the mocap cameras
  • A Synology NAS used for backup
  • A HP Z420 with a decklink Duo 2 capture card for reference recording
  • A Supermicro storage server (8th Gen x5600 running Freenas) for the reference video
  • A Cyberpower UPS as this room helpfully has emergency power buttons on the wall we can’t remove…

Most of this kit was gifted to us by our Cyber Security Dept and Cisco Lab, so cheers guys!

Recycle! The possibilities are endless!

Next up was reference video. Centroid were running their own in-house application, so we needed a different solution. I played with recording with FFMPEG (custom build with the decklink libraries) but the text ui wasn’t particularly student friendly.

Metus Ingest however seemed a viable alternative, and it hit all the requirements – multi-channel recording, text overlays, external timecode input, remote control over IP, perpetual licensing, and externally developed for updates!

The Vicon Giganet had it’s own timecode and sync generator, but there were problems with counting (of all things)!

At this point we’re up and running, with a few bugs, but these will be sorted out in the near future I’m sure!

The plan vs phase one

Rich Harper

Rich Harper

I’m a Creative Technologist. I build, create, hack, reverse-engineer, design and develop pretty much anything related to visual media.

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