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In October 2019 at Paris Games Week, we presented a world premiere concept: EVA, the first esports stadium in virtual reality over a surface area larger than 1000sqm! During this event, we’ve received many technical inquiries about how it works. EVA team has decided to share with you more about the technology used throughout PGW 2019!😊



There are currently two formats of virtual reality: VR arcade and Free roaming.


The VR arcade is the most common format that are easily found in VR arcades and often utilised by VR home users. The users have a limited space of 3mx3m, and require their controllers to navigate in its virtual environment. This means that the users are confined to small movements and interactions; bending down, picking up objects, dodging, etc. 


Free roaming on the otherhand is practiced on large surface areas in which players are able to move freely and therefore allow total freedom of movement. To navigate in its virtual environment, a player can simply walk, run, stop and dodge in real time, mixing virtual experience and real reactions. Being able to move freely increases the immersion of the player and intensifies the game design, making the experience even more realistic than the normal VR arcade format. 

Some alternatives such as treadmills exist with the promise of reproducing the feeling of walking freely while consuming very little space. Unfortunately this technology is still far from perfection and definitely requires a few more years of development for the product to mature and create a similar product to what was shown in the movie, Ready Player One.




Technology : Outside-in vs Inside-out


Tracking is a key element of VR because it is what makes free-roaming possible by capturing the player's real movements and positions to transcribe them into virtual reality. Two tracking solutions exist today, one using external cameras (base stations) installed within the play area and the other has cameras directly integrated into the VR headset, coupled with environmental recognition.


Outside-in Tracking 


Used by headsets like the HTC Vive, outside-in tracking is based on infrared cameras (base stations) that are installed in the gaming environment: living room, bedroom, LBVR ... These base stations will then detect the receivers on the VR headset and controllers to follow their movements accordingly and transcribe them into the game. The movements needs to be captured within the base station's field of vision, which has a maximum range of 10m. Therefore, most VR arcades offering free roaming experiences with a maximum surface area of 100sqm. 


Inside-out Tracking: Ditch the external cameras


External cameras are no longer required, instead cameras are integrated directly into the VR headset which will film and learn their surroundings to locate the players position and interpret his movements. The helmet will use the light contrasts of its environment to use them as an anchor point and record them in an internal map.

WMR (Windows Mixed Reality) technology notably uses Inside-out tracking, as well as the new generation of VR headsets such as Oculus rift S, the HTC Vive Cosmos, etc. 


Eventhough the manufacturers has announced a space limit of around 100sqm, the helmet will indeed continue to record its environment and track the players even if we exceed the set limit by the manufacturers. Therefore we decided to go with Inside-out tracking which turned out to be a great success, offering an opportunity to play on huge surface area up to 1000sqm.




Convinced by the potential of a large Free Roaming areas, we started out by offering experiences on a 100sqm spcae and quickly steered ourselves towards the inside-out technology, in the aim to reach surface areas larger than 400sqm and allowing quality PVP gameplay.  Unfortunately in theory, no technology could make it possible to meet these specifications.


Optitrack technology, using outside-in tracking with a large network of cameras, could acheive similar results, but its unfortunately too costly for us to offer a viable business model to our partners. In fact, to cover 400m2, we've estimated a budget of 300k euros just on external cameras purchases. It therefore seems very difficult for an LBVR to be profitable with an installation on a 500sqm arena with additional costs to be covered.


After several months of research and development, we finally chose to go with Windows Mixed Reality headsets, using inside-out monitoring. By mastering the constraints of this technology, we managed to exploit it in very large surface areas, exceeding the limits announced by the manufacturers.


1.  Static Bright Lighting
To ensure smooth operations, it is crucial to have a static lighting over the playing area, ensuring at least 500 lumens with a flicker frequency more than 50Hz.


2.  Effective Environment Set Up

As the tracking is based on detecting the light contrasts, it is important to have unique, clear, patterns as anchor points for the VR headset. Non repeating and non reflective patterns in black and white is ideal. The patterns should be of different siwes and easily recognizable close up or from a distance. 


3.  Synchronization Between Players To Avoid Drifting

Last but not least, the heart of EVA's technology that differentiates us from all our competitors - "zero drifting". As the VE headset has a fixed system of its own, time lags are created between players. The consequence could be serious because it could lead to collisions between players. The larger the space, the greater the risk of what we call, drifting. To solve this, our technical team has developed a separate algorithm for the WMR technology so that players are synchronized with one another, thus preventing any collision between players.  



Today, EVA is the only VR turnkey developer that offers quality and competitive VR experience in very large areas without drifting among players.


Now that the technology has been figured out, all that remains is to further develop our concept and imagine what VR esports will be like tomorrow!

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Topics: EVA, Technology, VResports, Free-roaming, Blog