metricminds shared some inside info about their Virtual Dungeon Experience (VDx). It combines the visual quality of the Oculus Rift and the precise motion capture tracking of the OptiTrack System. It was developed with Unreal Engine 4.
About the Virtual Dungeon Experience
During the preparations for hosting FRAVR, Germanys first international symposium about Virtual Reality, the team at metricminds strongly felt that they needed to contribute to the event. Due to the fact that this was a side project and that time was not ample before the event took place, the team had to overcome certain hurdles. In essence, the task was to make the experience come to life in less than three weeks.
The tools to create something amazing and exciting were already there: a 68 Camera Optitrack motion capture system, the Unreal 4 Engine and tons of creativity and know-how on the team. Leveraged by this symbiosis, the idea was to build an authentic environment and a very immersive and present experience for the player, using all of the ingredients mentioned above.
The project began with vague, brainstormed ideas, but over a short time, the content added up in the end to build a solid base from where new ideas blossomed and were ready to be realized. The result is an ancient and very dark dungeon, which each player gets to explore. The detailed virtual world surrounding the player builds a platform to make the experience authentic and believable.
The first task the adventurer is confronted with is to overcome the obstacle of darkness by finding a light source. Conveniently, there is a torch placed right at the entrance, which one can physically touch and take out of its holster. The ability to actually interact with props that have a life both in reality and in virtual reality gives the simulation a unique sense of realism and adds to the essential presence established right in the beginning of the experience.
The VDx is a short and adventurous exploration game where the player is tasked with the mission to escape the dungeon by exploring its mystery.
The major difference to other VR installations is that the player has absolute freedom of movement across a space of ca. 7m by 7m (23ft x 23ft). Additionally, they can interact with a number of objects that exist in the real and virtual world at the same time. The dungeon is designed in such a way that it works hand in hand with the OptiTrack Motion Capture System. Accurate position tracking and a clever level design allow the player to always focus on the game without breaking the immersion and presence in the world.
How it was made
The game is using a space of 23 ft by 23 ft (or roughly 7m by 7m). The 68 Optitrack cameras capture the movement of the Oculus VR goggles (to track the positions and field of view of the player) and all the objects the player can interact with. A motion capture suit, as used in traditional motion capture, is not required. The sense of virtual presence in the Player is achieved with a solid simulation of the environment and the fact that they can actually touch certain virtual objects.
metricminds decided to use the Unreal Engine 4 since it already has an Optitrack Plugin and can be easily used as a prototyping tool. The plugin allows real-time streaming of rigid body tracking data from Optitrack’s Motive into Unreal Engine 4. It also features HMD tracking integration for virtual reality devices like the Oculus Rift. So in conclusion, it was possible to create a quick and reliable setup that allowed fast iterations on world and experience design.
Once the plugins are properly integrated into the Unreal Engine directories, the OptiTrack and NatNet Streaming Client, as well as the Oculus Rift plugins are available within the UE4 project. The NatNet Streaming Client plugin allows you to stream live rigid body tracking data from the Optitrack Motive Software into the Unreal Engine. The Oculus Rift plugin makes it possible to implement HMD tracking into your game scene by creating the the Optitrack Client Origin object in your Unreal scene from where it connects to the server application via NatNet protocol and makes the rigid body tracking data usable. The Client Origin object also mirrors the global origin in Optitrack Motive and all streamed data will be referenced to it.
So in effect, if the player moves an object in the real world, the virtual object will follow the exact movement without a recognizable lag and therefore gives credence to the virtual environment the player interacts with.
The team also added ambisonic sounds and music, to create another layer of believability. Ambisonic sound is basically 3D SFX using stereo headphones. By using the position of the HMD to trigger sounds, it is possible to give the player a feeling for positions and distances of virtual objects. This way the player can be guided not only with visuals, but also with sounds. The team was astounded about the dramatically intensified experience through the use of music and sound effects. The most vivid example is the sound the torch makes when you wave it around.
The VDx can be seen as the next level of an escape room, where the player has to interact with the environment to win the game and succeed. The VDx can be experienced in private sessions at metricminds’ motion capture studio in Frankfurt, Germany as it is not permanently installed.
metricminds create animated entertainment using games technologies. The services include in-engine cutscenes and trailers, as well as animations used in games and movies. The company operates one of Europe’s largest motion capture studios located in Frankfurt, Germany. Metricminds collaborated on titles such as: Evolve, Gears of War, The Witcher, Dying Light, Star Citizen and many more.
Motion Capture is a process where the movement of an actor is digitized and transferred onto an 3D character. In order to capture these movements, special equipment is needed. Metricminds relies on an OptiTrack motion capture system. This system features 68 high-resolution cameras which record the movements of markers attached to actors and props inside a capture volume.
Alongside with their OptiTrack System, metricminds has acquired a tool set that not only will allow the state of the art studio to do outdoor capturing as well as recording up to 12 actors with props.
The FRAVR was Germany‘s first international symposium about the potential of Virtual Reality in the games and entertainment business. The event brought together international leading experts and business leaders from the games, entertainment, and technology industries to talk about the possibilities VR brings to the world of entertainment, and about the technologies needed to reach new artistic landmarks as well as sound business opportunities.