Thursday, 1 September 2016

Frogger VR - Converting the Retro to Virtual Reality

I recently was tasked with converting the 1981 Konami game Frogger, to a modern iteration that could be used with VR. I had a lot of fun writing this document. So I thought I would share my process and my work. What I first decided to do was dissect Frogger; find out what made it tick, and what features of the game were needed to cross over to VR to keep the same soul as before. This post will outline these features, before discussing multiple versions of a VR Frogger, and ultimately picking one I deem to be the more interesting and fleshing it out into a single page Design Document.

Original Frogger Gameplay

Before converting Frogger to VR, we should establish the gameplay elements that make up Frogger.
Frogger is a game where the player takes control of several frogs and attempts to make them move across a busy road, and then a river with flowing logs; towards 5 'Frog Homes' at the other side. Each time, the player makes it across; they must find an alternative route, as the previous frog then occupies that home. The game uses a top down camera to show the entirety of the level.

Each time the player starts as a new frog, they've 1 minute to cross to the other side before losing regardless. This forces the player to move quickly through the stage. The player has minimal control, and only uses the directional pad or arrows to move their frog.

During the first section, the player must navigate the fast moving traffic without getting hit, and waiting for opportunities to cross where gaps appear between vehicles. They'll then have a brief respite before needing to cross the river via logs, turtles and crocodiles.

The original Frogger is known for having the most ways to die in an arcade game; this includes; being hit by a vehicle, jumping into the river, being eaten by snakes, otters or crocodiles, riding a log off-screen and running out of time.

Breaking this down, we can take the elements that are actually important to CoSpaces' Frogger VR:
        The game uses minimal input.
        Move Frogs across the road and avoid traffic / Move Player across a busy intersection and dodge objects.
        Move Frogs across the river and avoid the water / Move Player across a hazard (such as a drop) by standing on objects.
        The Player has limited time to get across the level.


Converting Frogger to VR

Due to the player's perspective and fixed camera of the original; all of the elements of Frogger, should translate seamlessly into VR. This is because the game shows the player the entirety of the level at a time. But it becomes a question of whether or not you want to convert the game as is, or convert it to something that makes more use of the Virtual Reality Perspective. If you are looking to give more utility to the VR Perspective, then you have the following options:-

·        A Third Person Perspective that offered a unique perspective.


·        A Third Person Perspective with functionality that requires the headset to play.


·        A First Person Perspective that shows the level from the Player Character’s perspective. 
With a Third Person Perspective, we can, of course, replicate the gameplay of Frogger quite easily. We would start by replacing the fixed camera with the player's perspective. We can then add utility to the VR headset by giving a unique perspective. One of the ways we can do this is by making the level pan around the player’s peripheral vision; so that the game existed in a 180° or even 360° angle. In this scenario the player’s position would need to be fixed, so that they only turned on the spot. 

Similarly, with functionality that required the headset to play; we would start by replacing the fixed camera with the player’s perspective, but in this scenario, the level would only ever be in front of the player. This wouldn’t add great utility to the VR perspective alone, so we need to additionally give a reason for the player to be wearing the headset. So I would recommend that the player can use the headset to tilt forward and look at specific parts of the level in detail. The player will need to do this because certain sections of the level will restrict the vision of the player. It would be possible to build large structures that would negate the ability to see the Player Character all the time, hence, the player would have to move and reposition themselves to a place where they can see the level and the path easier.

The last option is to give the player a first person perspective from the Player Character. I would worry about the longevity and simplicity of such a game. Futhermore, I'd worry that the player's lack of vision would not be much fun, possibly even discomforting. The potential inability to not see ahead would be constant, and the need to be able to look both ways regularly, might cause dizziness and confusion. The reason the original Frogger works more efficiently is because the player has constant vision of their entire surroundings. And as such, any impending collision is always seen.

I believe the second option is the best option, as not only do I believe this game would be fun, but I also think it would have legs to show off VR as something unique offering a new way to play. This is because unlike the other two options, this version also requires the least amount of buttons to control also. The following is a 1 page design document to build such a game:

Construction Cross VR

Construction Cross VR is a game that takes a lot of inspiration from Konami's 1981 classic - Frogger. The game is set inside a building currently under construction, with multitudes of workers and machinery at work. The player takes control of the Foreman, as they attempt to navigate the hectic construction on each floor of the building. Much like the original Frogger, the game requires the player to avoid colliding with hazards. In this case (to make the game more friendly), they simply are dodging the rows of workers carrying bricks, pipes and wheelbarrows; as any slight collision will cause the whole operation to slow down. As the player moves up the building, the game gets progressively harder, with fewer gaps and faster obstacles. As Construction Sites rely on everyone being timely and efficient, the game also has a set amount of time to complete each level.
Construction Cross VR is a VR game that makes use of a Virtual Reality headset. In the image above, you can see how the game could potentially be viewed. The player character is in red, whilst the workers are wearing green. Moving right to left in the VR headset, might give you a better indication of impending collisions with the workers, as it gives you a better view of your surroundings. This system would also allow you to move up and down.

Controlling Construction Cross VR is also very simple, whether the game is only played with a headset or with a keyboard, the player can control the foreman easily. This is because the headset is used to direct the foreman to a location. Wherever the centre of the player’s headset is looking (identified with a reticule), is where the foreman will head to. Because of this manoeuvrability, the player only needs one additional button; which is simply held down to suspend the movement of the foreman (useful if the player wants to look around without directing the foreman), this will also hide the reticule to further instruct this paused state. Most importantly, this control setup will work with any iteration of VR and any headset, due to its minimal input. For example, if using Samsung Gear VR; the player only needs one of the buttons on the headset itself. This control system above all else; makes the game very user-friendly and accessible to all.