About

What is Mondradiko?

Mondradiko is a future-proof VR engine for creating multiplayer virtual reality experiences.

Future-proof?

Virtual reality is a rapidly expanding field of research, encompassing many topics, including optics, computer vision, machine learning, and embedded programming. As such, any development platform targeting VR needs to be ready to adapt to advances in VR technology, to provide a reliable and cross-platform user experience. Mondradiko will natively support new VR features such as full-body tracking, haptic feedback, eye tracking, and omnidirectional treadmills, as long as new VR tech is being created.

VR engine?

Mondradiko is structured very similarly to a traditional game engine, but VR can be used for far more than just games. Large-scale virtual reality will revolutionize internet communication, allowing businesses, teachers, artists, and performers to engage with their peers over the internet in a far more natural way than with what is currently possible.

Multiplayer?

Mondradiko is strictly designed around a client-server architecture, allowing multiple users to exist in the same virtual environment. Servers can be built to host virtual classrooms, professional meeting spaces, casual hangout areas, and of course, games. Your imagination is the only limit.

Virtual reality should be free.

Mondradiko is and will always be open-source and totally free. Under the LGPL-3.0 license, corporations like Valve, Facebook, or Google cannot make their own modifications to the engine without sharing their changes, meaning that you can safely run Mondradiko without having to worry about being tracked or spied on without your explicit consent. You as a user will always have complete control over what is run on your VR hardware.

Virtual reality should be accessible.

VR hardware is no longer something that only the most enthusiastic of gamers can buy anymore. There are so many options on the market now at a variety of different prices, that all anyone needs to become invested in VR is buy a standalone headset for the same price as a game console. We are now seeing VR users of all ages, genders, education levels, and nationality connecting online through VR headsets, and platforms made to host these users need to be developed for everyone. Localization, interface customizability, accessibility features for the colorblind and hard-of hearing, and strong social features are essential.

Virtual reality should not be a side thought anymore.

Engines like Unity and Unreal Engine, which have so far been the standard for VR development, lack the necessary tools for making high-quality VR experiences. Developers have to explicitly design their apps from the ground-up with VR in mind, leading to a huge range of the quality of VR implementations available to users. Some games might use a teleport movement system that’s smooth and intuitive, while other games have lackluster movement implementation that easily leads to motion sickness. Mondradiko lets you design apps that will work well on any VR platform, so that you as a developer can concentrate on making the content itself.

Implementation

Rendering

Virtual reality headsets run at very high refresh rates compared to most computer monitors and TVs (the Oculus Quest runs at 72Hz, and the Valve Index can go up to 144Hz). To provide a comfortable and smooth experience for the user, it is essential that a rendering engine designed for VR can maintain a very steady frame rate, and that it drops as few frames as possible. Some things that a VR rendering engine can do to increase comfort and performance are:

• Multiview rendering
• Fixed foveated rendering (and dynamic foveated rendering, when available)
• Clustered forward+ shading, with clusters shared between views
• Light bloom, flare, and halo effects modeled around the human eye
• Only rendering per-eye for close-up objects, and sharing a separately rendered view for farther away objects

Luckily, some post-processing effects that you may find in other rendering engines, like motion blur or depth-of-field, are VR-unfriendly, and can be omitted as render passes, increasing the frame budget.

Mondradiko uses Vulkan exclusively as its rendering API. The assumption is being made that anything that doesn’t support Vulkan (old/underperformant hardware) wouldn’t be worth using VR on. Additionally, Vulkan gives many more opportunities to optimize and parallelize the rendering engine in comparison to a more dated API like OpenGL, while maintaining cross-platform support.

Interaction and Input

Mobile (Oculus Quest)

As mentioned above, Vulkan is being used as the rendering API, which is compatible with the Oculus Quest. Because the Oculus Quest is such a popular platform for VR, it will be one of the major targets for optimization in Mondradiko.

I also must mention that my Quest is the only decent piece of VR hardware that I own at the moment. :)

Content Model

Mondradiko is meant to be used as a single executable, that will connect to a server and automatically download the content required (models, textures, sounds, scripts, etc), without recompiling the binary. This means that one universal client app can be used to participate in any online server. All engine content is decentralized, and loaded at runtime.

The server’s role is to run server-side scripts for running core world logic, manage databases for the users and their persistent data, and verify clients attempting to connect through a third-party, server-supplied authentication service.

Updates

As the engine gets updated, the network protocol will change, and engine logic will as well, breaking compatibility for any binaries running an older version. Because of this, a strong versioning system is necessary, to keep track of which clients are compatible with which servers.

Launcher

If a user wants to connect to a server that is running a different version than the client binary that they have, they will have to download the appropriate binary, and potentially reconfigure it to match their old graphical settings, comfort settings, custom input configuration, for example. To make this easier, an external launcher app can be used (depending on the host operating system), that shows which servers are using which versions, automatically downloads client binaries, and shares configuration data between version instances so that the user doesn’t have to worry about manually setting that up for every server that they want to connect to.

Modification

At some point, a server maintainer may want to fork Mondradiko to add their own features to the engine, which for whatever reason may not be feasible to merge back into the upstream repository. In this case, that maintainer would have to add their fork’s name to the versioning system, and potentially also distribute a custom binary if the network protocol changes. A launcher would make this much more user-friendly.

For more information on how these features are implemented, please see Design.