Hello everyone, I’m Cosmos 王柏堯 from National Taiwan University.
I am very excited to present my first UIST paper: Game Illusionization.
This project was done with my colleagues 徐琮賀，王品懿，黃新予，鄭人豪，張彧瑋，林雨新，and my advisor 鄭龍磻.
In this project, we propose a workflow for game designers to apply optical illusions to their video games.
Here shows an example.
This is a classic mini game where players move their character left or right to drop onto the next rising platform.
After illusionization, the platforms seem tilted, so players have to pay extra attention to the game.
By adding illusions, we increase the games’ difficulty and enjoyment.
Ok, but why do we do this?
During our survey, we saw Monument Valley and Superliminal.
These two games apply illusions to their games and hit a big success.
However, we still don’t know what makes a good illusion game since there are only a few cases.
This leads us to think, maybe we should teach others how to make illusion games first,
so we can have more illusion games.
And that’s why we propose a workflow to integrate optical illusions into video games in this project.
Here is our workflow. it has 5 steps:
choosing an object, searching for an illusion with our database, selecting a mechanic,
integrating the illusion into the game, and optionally revealing the illusion.
I will continue to use this classic game to elaborate more on our workflow step by step.
First, we have to choose an object from the game.
There are many objects to choose from
such as the platforms, the character, the remaining life, and so on.
Different objects result in different candidate illusions later
Here, let’s choose the platform.
Secondly, we look for matching illusions from our illusion database based on the object.
Our database contains 163 illusions in total.
This is our database interface.
And you can try our database with the link above.
Our database provides two meta-level tags:
visual elements and effects. By selecting these tags, we can find corresponding illusions.
The visual element tags describe what the game object looks like,
while the effect tags describe what kind of effect the user wants to achieve.
In this example, we search related illusions from visual elements.
Let’s observe the standing platform
It is rectangle, and parallel to each other,
so how about we choose the tags rectangle and parallel.
Our database then returns a list of related illusions.
Each contains a short animation and its name.
We can click the illusion for more info such as a short description and related tags.
In this example, we pick the Zollner Illusion.
The Zollner Illusion makes parallel lines seem askew.
After picking the illusion, now we have to think about how to apply the illusion to our game.
Here, we propose 2 illusion mechanics to think about
Misleading and Swapping realities.
The first one is Misleading
which increases the game’s difficulty.
To mislead players, we put both objects with and without illusions into the game.
In this example, since the Zollner illusion makes the platforms seem tilted
we can put both the illusionized platforms and the real tilted platforms into the game
Now players are hard to distinguish whether the platforms are indeed tilted or not
Trust me, what you see here is not what you get.
On the other hand, Swapping realities creates different gameplay.
To swap realities, players need to turn illusions into the reality of their games.
In this example, we disable the player’s movement
and allow players to add stripes to the platforms to make the platform “look” tilted
making the character slide from the platform to reach the goal.
By doing this, illusion becomes reality.
Also, this can be done in a reversed way.
Players remove the stripes by themselves to bring the reality back.
These two mechanics lead to different designs of illusion games
In this example, we take the misleading one.
Ok, we have a design in mind.
Next, we have to implement it.
We provide 6 specific illusion editors for rapid prototyping.
Our illusion editors integrate prior knowledge about illusions and help developers to apply illusions to their game objects.
For example, a prior work has shown how the angles of these extra short lines affect the strength of the Zollner illusion.
We then convert this knowledge into a Unity interface for developers to quickly adjust the illusion strength by the slider.
To use our illusion editors, just simply download and import our Unity Package from the link above,
and then assign the game object to add illusion.
We can also adjust more details in advanced settings.
Now we have an illusion game.
In addition, we also have suggestions for designers to reveal illusions.
Revealing explicitly makes players realize that there are illusions, rather than just glitches or bugs.
However, some designers do not reveal illusions because they want to use illusions as Easter eggs for players to find out.
So, we leave this step optional in our workflow.
There are three ways to reveal: Adding an indicator, changing perspective, and removing the interference.
We have more details about these in our paper
In this example, let’s choose removing the interference.
By removing the interference from the platforms,
we can see if the platforms are “really” tilted or not.
After our workflow,
the classic mini game has been illusionized to puzzle players and increase its difficulty.
And there are more example illusion games done by our workflow in this paper.
We illusionized a billiards, a territory game, a space invader, a road fighter, and a rhythm game.
These games are made with our other 5 illusion editors,
which integrate Munker, Footsteps, simultaneous color contrast, and Poggendorff illusions.
We have developed this workflow, and we wonder whether our workflow helps the game designers.
So, we conducted a two-week in-depth interview.
We invited 3 designers to use our workflow and implement illusions to their games.
All designers successfully developed their illusion games,
and thought our workflow helpful.
Here are their results.
In conclusion, we propose a workflow to integrate optical illusions into video games.
We provide an illusion database and 6 illusion editors.
With our work, we hope more game designers without illusion expertise to join us to create more illusion games.
Thanks for your attention.
If you want to know more details, please contact us or refer to the full paper.