Informative Trappist-1 Virtual Reality Simulation

by adelelh in Workshop > Science

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Informative Trappist-1 Virtual Reality Simulation

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This projects aims to recreate, in a virtual reality setting, the wonders of space exploration. It highlights one the most recent discoveries in terms of the search for exoplanets, the Trappist-1 system. Indeed, this solar system harbors planets similar to Earth in size and, for what we know, in composition. It is very small, but three of its seven planets journey through space in what is called the Goldilocks zone, which is just another expression for the habitable zone. Within its boundaries, temperatures are thought to be ideal to support liquid water. A planet with liquid water means a potential for life to develop, and here we meet one of the great purposes of space exploration, the answer to the questions everyone has asked themselves at some point: Are we alone in the universe?

This project consists of three general components. First and foremost, the virtual reality simulation shows the planets as accurately as possible in terms of relative sizes and orbital radii. The textures of the planets were also carefully selected to present an image that resembles the multimedia content NASA has made available to the public. For the journey through this exciting world to be as informative as it is spectacular, an audio voice-over track briefly summarizes a few facts about the planets and how they were discovered. Finally, for a full-on immersive effect, a soundtrack sequence was created and added to the simulation.

To use this project, one simply needs to download the virtual reality game file and put on a virtual reality headset. Press play in and enjoy the experience.

The purpose of this project is to inform the public about NASA’s great discovery in an exciting way. Because the project is informative and immersive, the subject is more likely to retain the information and develop an interest about the topic. This simulation can be used by anyone wishing to take a journey 39 light years away and learn about those currently closely monitored exoplanets. It can even be presented in schools in a science class framework as virtual reality could be a very innovative and appealing new way to teach material to students.

You Will Need...

Material

-A computer

-A MIDI keyboard

Softwares

-Unreal Engine 4 (available on https://www.unrealengine.com/what-is-unreal-engin...

-Garage Band (available on https://www.unrealengine.com/what-is-unreal-engin...

Texture Downloads

-3D texture (normal map) available on :

http://www.bing.com/images/search?view=detailV2&cc...

http://www.bing.com/images/search?view=detailV2&cc...

http://www.bing.com/images/search?view=detailV2&cc...
http://www.bing.com/images/search?

view=detailV2&ccid=dneZDZxI&id=AEBAB566CB1CD7CF6CF1B3E57FC4A8A91249E34E&q=normale+maps+&simid=608021268626868864&selectedIndex=4&adlt=strict&ajaxhist=0

http://www.bing.com/images/search?view=detailV2&cc...

http://www.bing.com/images/search?view=detailV2&cc...

http://www.bing.com/images/search?view=detailV2&cc...

http://www.bing.com/images/search?view=detailV2&cc...

-Planet textures (downloaded directly from Unreal Engine and https://celestiaproject.net/forum/viewtopic.php?f...

Other

Here is a very well-made NASA software that was used to obtain some of the data: http://eyes.nasa.gov/eyes-on-exoplanets.html

Research on the Subject

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Before getting started on any creative tasks, you need to know your subject inside and out, especially when an informative purpose is involved. We not only had to read about the system in general, but we also had to collect specific data such as the planets’ sizes, orbital periods and orbital radii in order to create an accurate model later on. Here is a list of website links where you can find information on the Trappist-1 system:

http://www.popularmechanics.com/space/a25336/seven-earth-like-planets-trappist-1/ http://www.trappist.one/#system https://www.jpl.nasa.gov/spaceimages/details.php?id=PIA21422 https://www.jpl.nasa.gov/spaceimages/details.php?id=PIA21428 http://www.nature.com/nature/journal/v542/n7642/full/nature21360.html

To make the task easier, we have provided a table including the data we used to create the simulation. However, note that you will need to read the articles in order to write an accurate text for the voiceover.

Convert the Data in Kilometers

In order to make the data easier to interpret, you may want to convert all the found values in kilometers. First, for the star, R. represents the size of the sun, so you simply have to multiply 0.117 by the sun’s radius. Than, for the planets, R+ represents the Earth’s radius, so you do the same calculation. Cross-multiplications are an easy way to get to the answers. Finally, to convert astronomical units in kilometers, simply multiply the values by 149 600 000.

Creation of the Skybox You Will Be Using

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For the creation of your skybox, you can decide between buying on the epic games market a space skybox or creating your own one. Because we weren’t experienced enough to create our own, we bought one for 20$ on the market, “StarSphere”. It gives you plenty choices of background, colors, space environment and more.

Add the Planets to Your Skybox

After you finished editing your skybox, you may now add sphere that will then be transform in planets. For adding sphere you may go in the Unreal Engin 4 starter pack and chose to add sphere. Add 8 sphere that will each be one of the 7 planets of the system and the last one will be the star. With the 8 spheres added to the skybox you may now all aligned them. To make it simple, put your star at 0 (y=0, x=0, z=0). After that, put each of your 7 shpere at y=0 and z=0 and just change the the x component to put them appart.

Scale the Planets and Their Orbital Distance

Scaling the planets is pretty simple. Use the radius of each planets and scale the sphere to this radius. Here is a video that will help you scale the planets: https://www.youtube.com/watch?v=uwCG787qp-M

After scaling the planets you should now take the orbital radius that you found on internet for each planet and convert it to put it in the x component to give the planets the real distance between each one.

Put the Texture on the Spheres (texture and Normal Maps)

For this step you should first upload all textures and normal maps in a folder in Unreal Engin 4. Then, you should first put the textures of each planet's. Here is video that will show you how : https://www.youtube.com/watch?v=4xTJq1hTPG0

After having all the textures on each planet's, you can now pass to the step of normal maps. (Definition : In 3D computer graphics, normal mapping, or Dot3 bump mapping, is a technique used for faking the lighting of bumps and dents an implementation of bump mapping. It is used to add details without using more polygons.) The blue parts in the normal maps are the spot where it will raise off the 3D plan. To apply the normal maps, look at this video that explain really well how to do : https://www.youtube.com/watch?v=HSufhA7Jj-U

Lightning of the Star

Making the lightning of the star is pretty complexe. You may put an emissive color light to make it glow how it should (it will make you see the effects of the star rayonnement). To do so, look at this video : https://www.youtube.com/watch?v=CtyNXjN_HFk&t=3s and https://www.youtube.com/watch?v=EIHua5fGGqo

After putting the emissive light, because the emissive light isn’t strong enough, you should add and other form of light to make the planet illuminated and give them a shadow perspective. For this, you need to add a “point light” and adjust the range for it to illumine all planet’s. Here is a video to do it : https://www.youtube.com/watch?v=Z2C4K1pLRqo&t=332s

Add the Starting Point for the Game

Adding a starting point in Unreal Engin 4 is pretty simple. You may just drag the start position point where you wanna start. Here: https://www.youtube.com/watch?v=wDrS8JDCpSc

Making the Matinee

Realising the matinee is the hardest step to make the VR game work. Here is a video that you should look at it closely and repeat everything that he does in your game : https://www.youtube.com/watch?v=N7CYnqOJpA0&t=198s

Composition of the Voiceover Text

Using the information found in the first step, write a text that will highlight the most important and interesting points about the topic. Make sure your text is not too long so as to eventually bore the viewer, but long enough to deliver the facts in one harmonious prose.

Record the Voiceover Text

For this project, the voiceover was recorded using the dictaphone app in the iPhone. Note that it is a good idea to practice saying the text a few times for the final result to sound natural.

Creation of the Music Soundtrack

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You will need to use an instrument of your choice to create a piece that will accompany the simulation. If you lack inspiration, take this moment to listen to pieces you usually listen to and try to mentally dissect them into their different layers to get a sense of how different melodies compliment each other. In this particular project, the audio sequence was inspired from Contact by Daft Punk (https://www.youtube.com/watch?v=JI5noh4OyXc) and a space- themed-ride soundtrack from Disney World (https://www.youtube.com/watch?v=azxQYf9KT94). It was played using a keyboard.

Record the Music Soundtrack

Ideally, you would need to plug the keyboard to your computer using the appropriate USB cord. However, for this particular project, that cord could not be found and we were forced to record using the dictaphone app in the iPhone. Therefore, the sound quality is not optimal. We strongly suggest connecting the keyboard directly to the computer to transfer your track.

Edit Audio Files

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You now have two distinct audio files: the soundtrack and the voiceover. Since, in this case, both were recorded on the iPhone, you can simply use Airdrop to send it to a computer that has the Garageband software. Open the software, and select “New Project”. A blank project window will open. Then, you can simply drag and drop the audio files directly into the track section in the left. Take this time to adjust the relative volumes of your voiceover and your music track to make sure one doesn’t cover up the other. You can do this using the volume slidebar in each added track. If your music sequence is not as long as your voiceover track, you will need to loop your music track for it to last the whole time.

Convert the Audio File to a WAV File

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For the final audio file to be compatible with the Unreal Engine file, you will need to convert it to a .wav file. First, you need to convert the Garage Band project into an mp3 file. To achieve this, click on Share in the top menu and select Export Song to Disk. Then, make sure mp3 is selected, and click on Export. Your track is now on iTunes in playlist called GarageBand. Now, in the top menu, select Preferences. This will open a window. At the bottom, you will see the Import Settings button. Click on it to open another window. In the first slide down menu, select WAV encoder. Click ok on both windows ta save the changes and close the windows. Then, still on the top menu, click on File, then on Convert. Choose Create WAV Version and save the the file. It can now be added to the Virtual Reality simulation.

Add the Audio File to the Virtual Reality Simulation

Adding a soundtrack to your game is simple. You first need to upload you soundtrack in a folder and then drag it on the game in a audio file. https://www.youtube.com/watch?v=qtgY7esjB6I

Make sure that the box for the sound is as big as the whole solar system.

Conclusion

At first, the aim was to create a virtual reality evolution of the International Space Station, but we ended up giving up the idea because we couldn’t find a usable 3D model of the ISS and/or its different units. All we could find was the model available on the NASA website, but it came unassembled (meaning in a few thousand pieces). We decided to stay in the space theme, so we went for Trappist-1 instead. Indeed, the articles had just started coming out and NASA had just released the information they had gathered on the system, so this was a refreshing subject to go for. It was clear for us that the topic showed an appeal.

It took us a long time to figure out the actual size Trappist-1’s host star. Indeed, we hadn’t noticed the symbols in subscript when R was used as a unit of measurement. We thought that, in all cases, R was the size of planet Earth. This made sense for the planets, but we were skeptical about this system’s star being only 0.117 times as big as the Earth. This being unrealistic, we read further into the articles we had saved and found out that the sun is supposed to be around Jupiter’s size. We ultimately found out that a + in subscript does refer to the Earth’s radius, but a + actually refers to our sun’s radius.

During this project we encounter some problems that complicated our life. We had small problems because we were new to Unreal Engin 4. This biggest problem we encounter was with the lighting. It took us few hours to find out why was the emissive light not strong enough to light up all the planets. We finally found out that we needed to add another lighting to compensate. If not, in general the project was going pretty well and this thanks to the youtube videos.

Our plan was to play our track on the keyboard and transfer it easily to the computer with a USB cord,, but, at the last minute, we realized that we couldn’t find the appropriate cord that came with it. As explained in the steps above, we had to record the track using an iPhone. It’s not the best quality, but it works.

Like any project, there are countless ways to improve the final product. If we had had more time, we could’ve figured out how to make the planets orbit around the sun to add more dynamic to the simulation. We also could have made the music sequence longer so as to not have to repeat it so much, which can get annoying towards the end.