Walking with dinosaurs: behind the scenes
Dinosaurs are once again walking the Earth, and E&T caught up with them - and their creators in York.
Everyone will have seen footage from the TV fact/fantasy documentary 'Walking With Dinosaurs', and marvelled at the computer-generated imagery (CGI) of dinosaurs apparently alive and well and roaming the planet. However, tangible, touchable creatures are now getting ready to tour the physical world, starting in the UK, and moving out to Europe and Asia.
When E&T caught up with the dinosaurs and their creators they were rehearsing in an old aircraft hangar outside York because they need somewhere big to house these life-size monsters. "Before coming here we mapped out what we are going to do with the dinosaurs and how they are going to be used in the show," says Scott Faris, the director of 'Walking with Dinosaurs'.
"[The next stage is to] demonstrate the choreography of the dinosaurs to the operators and puppeteers. We have a gridded miniature version of the stage and scaled models of the dinosaurs, and we basically play with them, moving them around to show them where they are supposed to go. The teams then go out on the floor and walk through the staging and discuss it, making sure everyone understands. Then the driver mounts up his critter, the voodoo operators go upstairs to operate them and then we try it with movement.
"It then becomes a continual process of refining. Ultimately the timing has to be very specific. There is a musical score and an actor - a narrator playing a palaeontologist - who provides information.
"We will spend about five weeks here just practising the movements, the timing, coordinating music, all the puppetry events and the actor performing. We then break it down and move off to another venue where we can set up our entire rig, including the lighting and sound equipment, and then we really start refining the performance. It falls apart for a bit and then we get back to running it again and bring the puppeteers back up to speed. The whole process takes about eight weeks.
This is the second generation of dinosaurs - the first toured Australia and is currently touring the US. "I got the first call in late 2005 and we opened in 2007 in Sydney, in January," explains Sonny Tilders, creative director of the Creature Technology Company. "We only had about 12 months from first being approached to getting the team together and finding a shed because we weren't initially a company, just a bunch of freelancers. I got the job of gathering them all together and creating a workshop facility. You take out rehearsals and you take out a bit of R&D at the start and we had an incredibly tight window to make these things and it was a hell of a year."
Hydraulics and weight
"We had to nail a lot of generic problems first, so we looked at some of the principal areas that we needed to explore, such as creating a lightweight durable skin and method of actuation. We were pretty confident that hydraulics were the way to go. We worked on about three dinosaurs at a time and slowly rotated them through the various departments of the whole workshop. In Australia, we had about 16 dinosaurs and for the UK and European tour we've added another three smaller ones.
"The technology really has evolved during the time we have been involved in this project," says Tilders. "We are still in the process of running a US tour, which are using the original set of Australia tour dinosaurs that we refurbished and sent over to America. They have been running for about two years now, so having all that feedback - not just technically but aesthetically and performance related - was a unique experience for me because I'm used to making one-off things for film and television and you never normally get a chance to do it again.
"This time around we had a bit more time and a bit more knowledge, so we were able to add those little extra bells and whistles - functions like snorts and breath vapour and eating mechanisms and that sort of thing. The Torosaurus actually engage in a battle of locked horns which we are able to do using some sensors which we have developed.
"One of the things that we are competing against here is that we really strive to make these things as lightweight as possible but of course they have to be durable; they have to tour," explains Tilders. "They not only have to perform but have to pack down into trucks, go on a long road trip, and unpack. All that is quite stressful on the chassis and all the components. But the weight is key to the fluid movement that we are after, so it is a real battle to get the weight down but obviously not have them collapse. Australia was an example of how we went a bit too far with that strategy where we had some major failures. Interestingly we didn't have a lot of show stops.
"One of the first areas for development for us was to create a skin that was going to be realistic, durable and - really importantly - lightweight, because the skin has a knock-on effect for the mass and weight of all the other things that have to support it. So a lightweight skin means we can have a lightweight structure; a lightweight structure means we can have a smaller hydraulic cylinder in the case of these larger dinosaurs, which has a smaller demand on a pump. So we can have a smaller motor in there, which means we can have a smaller set of batteries in the back of these creatures. However, we need the batteries as a counterbalance because these things are quite tall - the Brachiosaurus is about 10.5m tall, so we do need some mass in the bottom. Whenever we are playing round with things, if it is heavy it goes down the bottom; if it's light it goes at the top.
"One of the ways we have kept the weight down in the larger dinosaurs and this goes for the two Brachiosaurs and the Tyrannosaurus Rex and the Ankylosaurus, which use this approach, is to use positive fan-forced air inflatables. When you see them backstage they are deflated and they look like mummified creatures, but as soon as we apply power the large fans fill up air bladders throughout the whole creature and they start to take form.
Realistic muscles and skin
"Interestingly, it also helps us in performance. There is something about the quality of the inflatable - the way it jiggles, its mass and inertia - that reads really well and makes it look like a really big, heavy creature.
"Each dinosaur also has a series of muscle bags that link between the moving parts of the creature - whether it is a thigh or a tail - and they stretch and contract just like real muscles. Our skin technique is then applied very snugly to the top of that, so you see all this lovely muscle work translate through to the skin surface. This is something the audience appreciates.
Tilders is more circumspect when discussing the finer details of the skin. "How you get the textures into the fabrics is a bit of a trade secret. When we first started this job we knew we had to solve skins, and we went down a lot of paths using puff paint and quilted material. At the time we were pretty excited about it and it looked realistic enough, and then about two months in we came up with the totally different technique - still using a Lycra and still using a paint medium. But it is the way that we apply it that has given us this textural relief that is the key to the realism of these creatures."
Trevor Tighe, chief engineer for the Creature Technology Company, is responsible for the larger animation of the creatures. "What drives the characters around is the chassis, which gives structural support as well as supplying all the hydraulic fluid and power to the whole character," he says.
"In the chassis there are around about 18 truck batteries, which gives us a few dc power rails - the main one being 72V dc for a 10kW dc motor that drives an oil pump. This supplies power to all the hydraulic axes within the character. There are around 20 hydraulic axes, which are mostly hydraulic cylinders but with some hydraulic motors.
"That gives us a constant pressure in our hydraulic system where we use two valves to control every cylinder. What we have tried to do is make the system quite passive so you can actually push on the character while it's activated and it will move away from you and then spring back to the desired position; this is what allows the characters to move so smoothly.
Axes of movement
"We end up with quite a complex control system because we have so many added bits. We have the base of the body, which can rotate; on top of that we have the bottom of the neck, which can rotate left and right; and the bit in the middle of the neck, which rotates left and right. On the end you have the head, which can rotate left and right - and that is just in the horizontal axis. We do it all again in the vertical axis.
"The driver in the chassis moves the character forward and back and steers and looks after the onboard systems. When he drives forward and back there is an encoder on the front wheel which sends a signal to the legs to make the character walk.
"It also moves parts of the body to bounce and swing to make the whole walking cycle look good," says Tighe. "That walk cycle is just in one microprocessor, which includes a few smarts, so when the character slows down the feet sit back down on the ground again, so it doesn't stop halfway through a step. When you stop all the feet are on the ground and when you take off they lift and start moving again.
"The puppeteer driving the main parts of the body can also add to the actions in the walk cycle via a radio link. He can make the body move up and down as well, so the signals get added together.
Tighe explains: "The other thing that is happening within the chassis is that the foot is moved forward and backward by a carriage system, which is attached to the side of the chassis, so the legs aren't moved by hydraulics or anything inside the leg, it is actually the toe of the foot that is dragged forward and backwards and lifted up and down by hydraulics in the chassis.
"We then get that really nice look of where the feet are just missing the floor and always touching the floor without the need for highly accurate precise control systems.
"The wireless link we use is a spread-spectrum 2.4 GHz system so the communications are mostly from the puppeteer to the character. That has something like 20- 30 channels of data of positions coming from the voodoo rig.
"To operate the machine requires one puppeteer onboard and two other puppeteers in the voodoo lounge as we call it, where one guy drives all the major body actions. He has a controller that operates the main movements of the body so he just needs to move the head up and down, left and right, the body up and down and swing the tail. All of those things are built into this hand controller, which is designed purely for these characters.
"Alongside him is another puppeteer with a standard joystick and a keyboard. With the joystick he can open and close the jaw and move the eyes around, and with the keyboard he makes all the roars and sounds coming from the character.
Those three puppeteers are all talking to each other over a radio link, so they synchronise with each other just using normal communications."