Everybody walk the dinosaur

Posted on July 26, 2016 by Maxon UK | 0 comments

Creating anatomically accurate dinosaur skeletons for a Microsoft Kinect-based exhibit has proved something of a dream job for Stuart Pond Design

To celebrate the 50th anniversary of the UK government's Natural Environment Research Council (NERC), the organisation asked for ideas for ‘public engagement projects' – interactive exhibits for its Summer of Science that people can engage with and learn from. The NERC held a competitive bidding process, in which the most exciting projects would receive funding to bring the idea to life.

The Animal Simulation Laboratory of Manchester University pitched the idea for a dinosaur simulation that would enable members of the public to control a 3D dinosaur skeleton. The system uses an Xbox One Kinect that reads the person's movements and drives the muscles in the simulator, revealing how a creature of that scale and weight might move.

The project is the brainchild of Dr. Bill Sellers – a computational primatologist – who enlisted the help of graphic designer Stuart Pond. Pond has been working as an artist and animator for more than 25 years, specialising in scientific visualisation, but also has another, somewhat unexpected, string to his bow: "My other passion is palaeontology," he says. "Especially dinosaurs. I've been fortunate to travel to digs in the badlands of Montana and been on field trips into the deserts of Utah and Arizona, but my favourite area for finding dinosaurs is the Isle of Wight! It's here we find the dinosaurs and their footprints that I've been working on for the past few years."

He explains that he was a Research Associate at the University of Southampton for a couple of years before starting his doctorate. He planned his PhD (on Early Cretaceous Wealden ankylosaurs, in case you were wondering) so he could apply the skills he learned doing scientific animations to his research. "Working on this project allowed me to work closely with the palaeontology team at Manchester, which was a real pleasure as well as a learning experience, and use my passion for the 3D work I do on a daily basis as a working artist."

"I've been using Cinema 4D since it was ported to the Mac," he adds. "It's my choice for both commercial work and research. It's important that my PhD also feeds back into my day job, as being a scientist as well as an artist enables me to communicate effectively with the medical scientists I work with and has helped develop my research skills. Learning new skills is essential for both artists and scientists, and I'm lucky enough to be able to do both. Science and art are a powerful combination!"

The dinosaur simulation is driven by a modified version of the GaitSym multibody dynamics system, developed by Dr. Sellers. It's a forward dynamics modelling program that lets the user apply forces to a skeleton, and which then uses a physics engine to calculate the motion. In the case of GaitSymKinect, it uses the input from the user's movements applied to 3D dinosaur models as a means of showcasing the real-time physics and to help understand how fossil animals might have moved.

Once Dr. Sellers had the go-ahead from NERC, the first thing was to create some high quality 3D models of a variety of dinosaur skeletons. Stuart Pond was contacted by Dr. Charlotte Brassey, who works with Dr. Sellers, and explained the concept behind the project. After a meeting to discuss the details, Pond got to work on building the skeletons.

"Making the models as accurate as possible was key," he explains, "as they would need to be rigged with virtual muscles. We also needed to keep the polygon count as low as possible so the software could animate in real time, and the models needed to be suitable for 3D printing. All the bones were modelled from scratch and to life size within Cinema 4D."

Before starting work, Pond sourced data from LIDAR and photogrammetry scans, as well as referring to scientific literature and first-hand observation of fossils and casts. "A skeleton has a lot of bones and each needs to be looked at individually to ensure it's correct when modelled," he says. "Modelling organic structures brings its own challenges and this encouraged me to think about the shape of each bone before I started work on it."

He began by blocking out the shape of each bone in Cinema 4D, using as few polygons as possible. The basic form was then taken into ZBrush, where Pond sculpted the finer details before using zRemesher to retopologise the mesh. This was then transferred back into Cinema 4D using the GoZ bridge, where he could use the native sculpt tools, and then assemble each skeleton before exporting to FBX files for use in GaitSym.

"I did this because ZBrush's sculpting tools are quick and easy to use," he explains, "and I find the sculpting workflow and symmetrical modelling much more intuitive in ZBrush, which is vital when creating a dinosaur skull, for instance. I did use Cinema's sculpt tools for adjusting many of the models though, especially the vertebrae where taking each one individually into ZBrush would have proved too time consuming. I like the fact I can move freely between the two apps as this is very important when setting up a workflow for any project that involves a lot of modelling."

Most of the bones were sculpted separately, although Pond admits that some of the vertebrae were simply adapted from ‘master' models: "These bones are repeated many times in the skeleton and whilst each bone is unique there are quite a few common features and you can take advantage of that. In these cases I would model a cervical, a dorsal and perhaps two or three types of caudal vertebrae and then adjust those in between with Cinema 4D's sculpting tools."

Cinema 4D's MoGraph toolset also came into play for replicating and positioning similar bones such as vertebrae, saving Pond hours of work. "I would replicate and scale the various parts of the vertebral column (for instance the vertebrae of the tail) using MoGraph, then convert to meshes and adjust the sculpt and reposition as required. In the case of Edmontonia I used MoGraph for much of the armour as many of the osteoderms [bony plates or scales] are pretty much the same shape, with some repositioning by hand."

Overall, Pond created around 210 bones for each of the six dinosaurs, taking about three days for each model. The armoured Edmontonia took longer because it features an additional 178 spikes and plates. "However it was worth the extra effort because it looks really cool," he adds.

GaitSymKinect and all the skeleton meshes are available for download at www.animalsimulation.org, so you can try them for yourselves in Cinema 4D. And despite their use in real-time visualisation, they're surprisingly high-res. "GaitSym is more than capable of handling models with this sort of poly count and greater," explains Pond. "We wanted to make these models as useful as possible to other researchers and so the mesh density was kept as low as possible whilst retaining scientific accuracy."

Clearly the combination of art and science has been the ideal project for Stuart Pond Design, made all the more special as his creations come to life within the GaitSym software. "It's always a thrill seeing your work being used in any situation and in this case it is very satisfying to know we can get actual data using these meshes. GaitSym is a remarkable piece of software and I'm very pleased the models work as planned, both in the Kinect version that allows users to control the dinosaurs and in the version Bill uses for biomechanical work. The fact they look good 3D printed too is great – I love the idea a person could print out a full-sized Tyrannosaurus rex if they wanted to."

Stuart Pond Design Website: www.stuartponddesign.com.

All images courtesy of Stuart Pond Design

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Hitting CG out of the park

Posted on July 26, 2016 by Maxon UK | 0 comments

T20 cricket is an all-action sport that required an equally energetic promotional campaign, as Duncan Evans discovered

Having already produced two previous promotional videos for Nottinghamshire County Cricket Club's T20 team, otherwise known as the Outlaws, Pete Black, Head of Post Production at Affixxius Films, knew that this third instalment would be the most ambitious yet. A team of just two CG artists and one visual effects supervisor had only two months to create a three and a half minute film that utilised motion capture, actual cricketers and even a foe in the form of the Alien Cricketer.

The concept was that in the previous films, called Cricket Has Landed 1 and 2, (www.youtube.com/watch?v=kHyaN-5cBpI and www.youtube.com/watch?v=wi8hWMAdlNI), the Outlaws had fended off an attack on Nottingham. In this concluding film the aliens unleash a devastating force and steal the "spirit of cricket," hiding it deep within Sherwood Forest. The film follows the players as they attempt to take back the spirit of cricket and save the day. As the first film in the series won Best Promotional Programme at the Royal Television Society Midlands awards in 2014, Pete knew they would have to come up with something special to better it.

To start with, it meant using mocap information to drive the animation of the Alien Cricketer. This took half a day in the studio but at least with Cinema 4D it was straightforward importing the mocap data. The entire video has a Japanese anime influence which was typified by the Alien Cricketer design. This was designed by Kieron Edwards, a concept artist that Affixxius worked with. He was briefed to make a character that was very imposing but had armour that was based on cricket equipment. It took the team 10 days to model the alien character which ended up with 39,897 polygons.

Pete explained how they went about creating the motion capture, "We worked alongside AudioMotion to capture the movements required and then Dan, one of our 3D artists, translated the information to the character rig he'd made in Cinema 4D. Due to the size of the character, 10ft tall with a large chest, we had to be mindful of the limitations to avoid the arms intersecting with the body." To do this the actor being captured was directed to hold his arms out wider than his actual body, but this only minimised the issue. The data was then manually adjusted using the rigging tools to fit the large frame of the alien.

The next challenge was to create a CGI forest for the players to be set in. This is where Cinema 4D's MoGraph tools made life easier as Pete revealed, "The MoGraph tools made building the 3D forest really simple as we were able to use cloners with random effectors. We used a total of seven trees in a cloner with a random effector attached. The foliage was animated using XPresso which drove the various effectors applied to the ferns."

As the action starts in the forest you can also see one particularly large and old tree. This is the Major Oak, which is actually in the middle of Sherwood Forest and according to local folklore, was used by Robin Hood and his men. The tree itself is over 800 years old. To create it in the film the main sculpting tools used were Pull, Smooth and Pinch. Pete pointed out that, "The convenience of having the sculpting all within the same application made for a seamless workflow. Sculpt layers helped to add levels of detail onto the bark."

The cricketers themselves were filmed in a green screen studio, and lighting plans were drawn up in advance so everyone knew where lights were going to be positioned. Wind machines were also used to help with interaction. The Director ran the players through each of the scenes and gave them reference points, such as the alien will be stood here and you need to be looking there.

However, at the end of the day, they were actually cricketers, not actors, so some retakes were required. Still, Pete was impressed with how they acted in front of the camera, "On the whole the players were very good, most had been in the previous videos so they knew the process. Steven Mullaney in particular was very good in front of camera giving some great performances."

After creating the environments in Cinema 4D and completing the filming they were composited in Nuke. Pete pointed out the benefits of a smooth pipeline between the two, "We're really starting to get to grips with the workflow between Cinema 4D and Nuke and the results are getting better every time. It was a very quick turnaround for our Post Production department as we only had approximately two months to complete all the shots."

Given the complexity of the project and the small team involved, Pete admitted that it was tough to turn it round in the two month timeframe and added, "There were a lot of late nights and pizzas consumed. Once we received all the data from the motion capture company we did notice that the alien's 'Big Laugh' scene looked like he was dancing rather than laughing. The scene does feature in the final video but we felt it was clear he was laughing when the audio can be heard, making it less Saturday Night Fever and more like an alien chuckling."

In the end it took around five weeks of rendering across a render farm of 10-12 machines to output the three and a half minutes of film. It has the slightly unusual resolution of 2048x858. Pete explained why, "We shot the project on an ARRI AMIRA, which shoots at a native resolution of 2048x1152. We then opted to cut the film at cinema scope 2K, which gave us a cropped height of 858."

Given the heavy workload and intense schedule Pete was also thankful that C4D was up to the task, "Cinema 4D is the most robust software I've ever used. It may take time to think about complicated scenes but it'll hardly ever crash."

Watch the Behind The Scenes movie: www.youtube.com/watch?v=T0MvURegLwM

You can see more about Affixxius Films at www.affixxius.com.

All images courtesy of Affixxius Films

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