Building Augmented Reality Experiences with Unity3D - Abhishek Singh - CS50 Tech Talk

thank you all so much for coming we're really excited about today's talk cs50 as you may know it's been experimenting in the world of virtual reality or VR over the past year and we've had our eye on augmented reality or AR which you might know in some form from like Pokemon go like a year ago you were playing that quite a bit our friend Abhishek here though from NYU who recently finished up there has been working as a resident researcher truly took things to the next level he went viral recently as you may have seen with his implementation of Super Mario Brothers in augmented reality and while perhaps a bit socially awkward it's been quite a bit of time walking down a path in Central Park creating this amazing world that he's kindly offered to share with us today so Abhishek Singh thank you hi everyone I'm Abhishek and let me just kick these things off I mean David's already done and in two introduction but let me just go over it again so I graduated last year from NYU IDP and ITP is the interactive telecommunications program at NYU it's kind of like a mix of a design and tech an art kind of program and that's where I kind of started doing a bunch of crazy odd slightly off kind of projects one of them was this shoe and the shoe is something that you can wear and you can control and customize completely from your phone another thing that it did was an interactive installation in Times Square so this went up on a 40-foot billboard in Times Square you could text in what outraged you on the Internet to that day I also built this 20 foot dragon that you could sit on and ride and that way why riding it you were controlling a dragon or what's your recreation of this dragon you know in a virtual world as well and pointing that I also made this little desktop assistant and this is the assistant that responds to your voice but he responds entirely through gifts and this actually was the project that went viral prior to this current project and yet here I am today talking to you guys about AR so how exactly did that happen well David already reveal that but I'm sure all of you are familiar with this like this might have been Korea prior to most of us being born but at the same time we all recognize it and we all kind of grew up and played it at least once right and this is Super Mario Brothers and what I did was I recreated this except I recreated it in AR as a life-size first person game so I took the iconic first level of Super Mario Brothers and rebuilt it for the hololens and that's what i'm here to kind of talk to you about today in addition to my experiences of building this game i also want to just talk to you about augmented reality in general and also some of the tools at least a cursory look at some of the tools that are available to us to start building stuff in ER so AR is essentially taking worst virtual objects and placing them into the real world but i say not just placing them into the real world but also placing them with them having knowledge of what the world around them is knowledge of surfaces and maybe being able to even interact with them and to be honest AR is quite pervasive already right we all know about snapchat filters and we use them like on a regular basis and this is AR to some extent it's augmenting a reality and snapchat is pushing this further now so they have taken that and they pushed it to what they're calling world lenses in which their stickers are these 3d objects are actually aware of where they are placed positionally in the world and apple recently made a huge announcement and they released a arkad like opening up hopefully to what we'll need much larger adoption amongst consumers and all this comes under under a subcategory or a subset of AR which is called markerless AR so Mark Ellis AR is essentially what is based on a technology called slam and slam is simultaneous location and mapping so what is doing in this is using the device's camera but is using the device's camera to essentially figure out unique spots surfaces and planes within the environment once he figures that out in real time it can then move around pan around the objects and keep them fixed fixed and anchored to their actual location compare mark lists to the other thing which is marker based AR and it's not QR codes but it's kind of QR codes on steroids and QR codes and sales is something which is being used by this company of euphoria and it uses similar except is less computationally intensive and this is less of a technological challenge what it does is it takes a unique image that you can upload so you can upload any unique image and it uses figures out points within that image and using the distances and the positions between that points it can find out the angle of the angle of the image and accordingly figure out how it needs to orient your hologram or your virtual object on top of that image so that's mark of a stage now they would mention this earlier Pokemon go I haven't mentioned it yet and the reason I haven't mentioned it yet is because when Pokemon go released a teaser video this is what they should write this looks like here like the objects are there they're in the scene they're interacting with it but when the app actually launched this is what you got right and this to me is not true error the reason is not true here is because the Holograms or the virtual objects have no idea and they have off of the environment around them they have no idea of surfaces they don't have no idea of objects and they cannot interact with it in any way it's simply just a screen with a sticker overlaid onto it right but all of these still come under the category of what is a mobile layer what Apple Facebook and now so and obviously snapchat for some time have been pushing if you compare and mobile layer is essentially your mobile headset or your mobile handset is a window into the world so you point your handset at either a surface or at a particular marker and you see a hologram in its place on the other hand as compared to mobile you have these headsets and Microsoft is obviously pushing a lot in this and it's probably got the most sophisticated has set out there right now which is called the hololens and it they call it holographic computing it's a headset that you wear on your head and you can see objects overlaid in the environment it has since it's a completely new form of computing it has completely different interactions we all use to mobile interactions swipe tap all those things but for the hololens it uses these four forms it uses gaze which is essentially where you are looking it uses and these are specific gestures I'll just cover shortly it uses voice similar to Siri and it also has a clicker that comes along with it which can double up as a mouse and interact with objects that you're looking at so the two gestures that the hololens supports is the air tap the air table is you make a tap and you just kind of tap in front of it and this is similar to what a mouse click would do and the other one is the bloom and the bloom gesture is just like the home button on your iPhone whatever wherever you are it will take you back to the home screen well what the holliness does really well is spatial mapping so it has a bunch of cameras for cameras to be precise and the depth sensor which is similar to what the Microsoft had in the Kinect which you can then look around in your environment to map it out and so it knows where the surfaces exist where objects is exist so that you can actually place your holograms on those surfaces or have them interact with those surfaces in real time the only issue I mean one of the several issues and this is obviously a very early I would say prototype or development kit of a headset is that it has an extremely narrow field of view so it's not as immersive as well if you have tried what your reality is not as immersive as that but it's definitely a big step towards having these headsets and for me headsets is definitely something which is not probably going to happen in the next couple of years but maybe five or seven years from now just because it keeps your hands completely free so mobile is a good first a stepping stone into air let me begin by how I got to making Mario and it actually all started with this one simple cube up here so and I must be wondering how I started with this cube and I'll get to that so it when I got an access to hololens and that's the great thing about universities is you get access to technology and equipment that otherwise you probably couldn't afford I already knew that what I wanted to create was a large expansive outdoor experience the hololens and the microsoft fa Q's they specifically say it's meant for indoor use and it is not meant to be used outdoor ends meant to be used in kind of small quarters but I always saw the opportunity of air to be something that you can use outdoors something that you can move through something which may have a fitness element to it something that that would actually take technology out from within the rooms and into the real world so I decided that I'm going to create some sort of street runner game right I would create a game that would exist in the streets of New York and I would run through it completing it and probably possibly record it just for my own fun while I was learning hololens development and everything starts with like either a bouncing ball or you have like a cube that you place and there's the basics the absolute basics I took this white cube and I kind of moved it around in this space I've moved it around in 3d space in the hololens except during one of those tests I placed it slightly above my head and for some unknown reason I stepped under it and I jumped and then as soon as I jumped all the memories from my childhood came rushing back and I was like this is Super Mario and this is this white cube is the brick that I'm supposed to birth that I'm supposed to like hit with my head and have a mushroom come out of so so starting with that I was like Super Mario Sol's everything that I was going for I wanted to create a large experience I wanted you to be outdoor and it added the other additional thing that it now had a purpose like what my game was lacking I did not know what the purpose of my game was but Super Mario had a purpose the player is moving through it to reach the end to complete the level and in addition to that it has this huge legacy behind it right everybody is immediately relatable and I knew that it had viral potential so the first step was a ton of research and a ton of research meant watching the video on loop over and over again till I practically memorized every single interaction and every single element on that it also meant going at back and playing the game something which I hadn't done in in several years to actually get a sense of all the game mechanics after I had done that I was the next step was recreating in 3d and the first step to recreate it in 3d was to get a handle of the assets I was I thought this would be pretty simple super Mario's been for 30 years people have definitely created 3d assets that he could easily download for free online and include them into my game but that wasn't the case it wasn't the aesthetic that I matched and it was priced at a ridiculous $5 it's now at a discount so it made more sense to instead spend one week building it myself well it at least made it made made more sense at the time in retrospect probably five dollars would have saved me a lot of time so I decided that I'm going to design all the elements myself so I picked Autodesk fusion 360 which is like a CAD program and I started designing these elements the only problem was that I have only been used to seeing the elements in this way I don't know how they look in 3d I don't even know what the underside of this brick looks like so I took that reimagine and rethink all these elements at how they would go in 3d so it turns out I decided that this is how the brick would look instead and this is how the underside of the brick would look and then going back I found 2d cutouts of all the elements and then recreated them in 3d so this is the goombah which for the longest time i used to call bad mushroom and this is the koopa troopa which i obviously always called bad turtle so once I had all the assets are built out the next step was bringing it into the game engine of my choice and the game engine of my choice is unity not only because of my familiarity with it but also because it's the one that supports halogens development and has an SDK which allows you to build and deploy to the hololens so just a quick segue into unity for those who are not used to it or not familiar with it unity is essentially a game development engine which has democratize the creation of 2d and 3d games for developers everywhere it's pretty simple when you think of it you create an object and you attach a script to it and that script allows you to give that objective behavior add interactions or add animations of any sort and you can script it in multiple languages c-sharp JavaScript unity the reason of listing this order is because this is the popularity of the community everybody kind of prefers see shop and you'll also find many more links and many more help tutorials on that so once I brought it into unity the next step was painstakingly recreating the entire stage right in that stage but not only the entire stage but each and every single game mechanic and now when I think of it and when I look back I'm like truly amazed of how these programmers were able to do this in like 1985 when there was no Google there was no Stack Overflow and you had to basically figure all these things out yourself so building the level took some time and at the end of it I was able to recreate this entire level so what you're seeing here is the unity interface and you can see the level within it but it's not in 2d as you see I kind of scroll around all these elements were then recreated in 3d and I built this to scale so I built this to human scale so the final length of the entire level was about 110 meters long which means I needed a space which was at least hundred and ten meters long to be able to play it myself there are obviously several challenges along the way and what I like to call several hacks or programmatic illusions that I had to undertake to actually bring Mario to life because Mario after all is a video game right so he can defy the laws of physics which are not necessarily possible for me yet so so one of the things was he can jump twice his height I can do that and at the same time he can collide with bricks and I can't collide with Holograms so how do I kind of work my way around that to do that to do that just to kind of get an understanding is that the hololens knows its position in space so the hololens is placed on my head it kind of knows where it is located in space so I attached a Collider to the hololens starting from my head and moving down to what my height is and I attached a Collider to every brick 3d brick in the scene except the bricks had to be much higher to give the same effect so I just offset the collider from the bricks so brought to collider down the colliders are invisible they're not visible to anybody but by jumping just a few inches off the ground I could still collide with them and have the same interaction alright so now you can see bricks up much higher than I could possibly reach but I'm still able to jump and interact with them and get the coin out of it the next thing was spontaneously growing when you eat a mushroom so yes I can't spontaneously grow either so how did I achieve that instead of me growing I decided that everything around me would shrink so that would give at least the illusion that I had now grown the other thing that you see in Mario is there are several visual cues which we should accuse interspersed throughout the game as soon as he gets a powerup his costume changes and he has this kind of blinking effect so I couldn't figure out how to do the costume change but I did figure out how to do the blinking effects okay as soon as you hit that the powerup you see kind of this overlay which mimics the blinking effect so you know you've got the thing but stripping and in immediately changing in the middle of Central Park was little bit off limits and and finally the other thing is that how do I interact with something that doesn't really exist right the Holograms have no physical I mean they have nothing there is no material they're just completely creations of light and he's supposed to jump around a jump on these Holograms jump on these pipes so I found it really simple fix to this I was working in 3d so I decided to just walk around them and then moving on like these resists what I like to call programmatic illusions but in addition to that there are also a bunch of hacks and a bunch of hacks with the to tweak the hololens to work over such a large expanse the hololens is meant for indoor use it's meant to be used within small quarters it's not meant to be used outdoors on a flat surface which has very little differentiation on it like a road five meters from here looks exactly the same as the road five meters behind so it's very difficult for the hololens to figure out what it saw or what it's going to see and at the same time it was outdoors and it's over 110 meter expanse so to achieve that I had to do a number of hacks but the first thing before reaching any of that I realized was then what if someone else wants to play this game what if someone else who is not as tall as me always much taller than me wants to play this game everything would be lower for them or higher for them and they would not be able to complete it so the first step what I did was I integrated this calibrator of sorts as soon as you start the game you first enter your height in centimeters and once you enter your height in centimeters it calibrates the level to your particular height so if you are really short the bricks will be closer to you and if you are really tall the bricks will be further above so respective of whatever physical build is you will be able to complete the entire level after that I went about like scouting a location and in scouting location I I did make a mistake I spent too much time developing indoors in my computer rather than going and testing outdoors in the actual location that I was going to shoot so I picked Central Park and I picked Central Park this area is called the mall in Central Park and it's the only straight stretch of land in Central Park and probably in New York which is so empty that I could actually go and play this without being run over by a car or arrested by someone so so I picked this place and as soon as I went to this place and the first thing I realized was that the hologram so much more transparent than when I was filming them indoors and that's the reason why Microsoft also recommends that you film that that you used the Holograms and used indoors the reason is that indoors you can control the lighting the lighting is more consistent it's not as harsh as sunlight so the Holograms which are based essentially on playing with light are much more opaque to get around that I'm I again found a programmatic hack instead of capturing the video directly through the hot - the hollowness I did capture the video directly through the hololens but instead of capturing through the hololens hardware itself i captured it to be from within my app running on the hololens so i wrote a custom script that would allow me to increase the opacity of the holograms as they were being captured so while this is the exact view and the reason why I have added these translucent cue of this translucent squares on the edges is that this is the actual field of view of the hololens what you are seeing and and the rest of it is what is captured by the hololens cameras but it's not what is visible from within the headset so I figured out how to get the Holograms to be completely opaque which was extremely necessary for me at least just to show the potential of a are and just to get the point across because it was much more compelling seeing it this way than seeing a translucent washed out hologram instead but every action has some kind of reaction and the result of this was that the hologram the hololens sees everything that is black as transparent so that's how everything that is black gets overlaid with the real world so I had created these bits right the pits that you remember in the stage that if you fall into you kind of die I created these pits and I created the exterior to be completely black so that they would be completely transparent to the hololens but as a result of writing my own custom script to capture this the holograms were now being rendered in my final capture as completely black so even though in the hololens while I was walking around everything looked fine in the final video capture it was looking like one gigantic black cube embedded into the floor so to find a way around this I tried two things both were writing custom shaders so shader is essentially like a program which gives you on a pixel or vertex level control so you can define how every pixel is rendered on onto the screen so the first thing that I did was I wrote a custom shader that essentially what it did was it made the black transparent to the camera but opaque to everything behind it so as a result of that I could not see anything unless I stepped right over it but the problem with this was that it was extremely computationally intensive and as a result of that the final capture was extremely jittery and there was too much drift and lag while I was moving through the stage so instead of that I use something called the stencil buffer and a stencil buffer is some is what you can consider to be a mask so everything that you see through that mask is visible and if you don't look through that mask it's not visible and the resulting effect is something like this so you can walk up to the pit and you can look down and it looks completely overlaid onto the floor and the stencil mask or the stencil buffer is no overlay right on top of it so it's like a window into this object but it's only when I look through this window that I can see anything that's inside it all that was fine but as a result of not testing outdoors enough the other issue that arose was that there was a lot of drift and when I mean by a lot of drift was the entire level as I moved further into it was shifting tremendously to the left or the right or up or down and you can kind of think of that as a pivot right if you if you look at my elbow and if you think of my elbow as a pivot as I move my hand everything that's further away moves moves more than everything that's closer to the pivot and the result of and the issue was that I had one single pivot I had one single pivot where the stage was initialized so any movement any recalculation that the horror that the hololens did to figure out where it was positioned in space shifted everything further into the stage by a factor of five so to get around that I had to do the biggest chord rewrite ever practically go back to scratch and split the stage that I'd now coded as one gigantic stage into small sections into small chunks so I took the entire thing and split it into 23 sections right and each section had a spatial anchor and a spatial anchor is something that the Holland's can use to anchor a hologram in space so each of these cubes that you see on the screen over here what was used as visual cues by me to signify the start and end of the section and there was an anchor which is obviously invisible completely based in the center of each section and by placing the first anchor so I will just place the first anchor on the floor and then place every subsequent anchor completely perfectly aligned to it following that so the end of it each even though the entire stage was working as one cohesive whole it was actually made up of 23 different parts each part being anchored completely independent of each other and that helped get rid of the drift completely and also helped its steel level on the floor once all these kind of issues was sorted out and there were bunch of other things which if I get into will probably be sitting here all day I decided that it was time I did it's time to finally film this and put it out there but before doing that I obviously had to dress up as Mario because the entire entire point of this was that it's a first-person game in which you step into the shoes of Mario's so you are Mario so I had to be Mario so again it was kind of a dear do-it-yourself kind of outfit I purchased the overalls from Amazon I had a full sleeve overalls and the gloves were from Amazon I built the buttons the yellow buttons out of wood just kind of taped them to myself and I luckily had a full sleeve red t-shirt so after that I went ahead to Central Park went early in the morning because one it's less crowded right I would get fewer well weirded out looks and at the same at the same time the light was less harsh so as the sunlight gets harsher and harsher it's worse for the Holograms to perfect itself so let's just have a look because it was not just about the Holograms looking perfectly it was also about the audio working perfectly a lot of the things like I cannot physically feel a hologram so I had to rely a lot on audio cues to know that I had performed the correct tasks or the correct event had kind of occurred so Maya obviously has each and every asset file of the audio available online so I just use those and trigger them at perfectly the perfectly timed events but it was not just about what we are used to see in Mario right the other thing is like what we're not used to seeing in Mario and one of the things that I always wondered was what was inside the castle at the end but now that I was building it myself I was like okay now we can actually see what's inside this castle at the end and since it's like a 3d castle you actually get to walk into it and look up so the end of the stage once you clear the level unfortunately I couldn't slide down that flag you simply step into the castle and the cast is a life-sized it completely occludes everything around it and you can see that not only does it a set of the flag but you can look out through the windows you can look out through the roof and you can look out through the door so I kind of had this headline in my head I was like okay this has kind of viral potential the end effect looks really good and probably someone is going to post this saying like crazy dude in Mario costume seen running through Central Park early in the morning but but I kind of underestimated in New York I didn't get a headline but it was no one thought it was real but but I beg to differ because I was able to then zoom in on someone and I did get a bunch of looks so there were definitely of confused looks but then again it's New York so people have definitely seen things weirder than me jumping around early in the morning in Central Park and it led to a lot of interesting conversations a lot led to a lot of people just kind of taking pictures figuring out what exactly was happening because most people had not seen a hololens before and most people were not familiar with augmented reality or virtual so there was a lot of I guess interest by seeing what I was doing there earlier in the morning once I shot this and I shot this on a Tuesday I posted it out on Wednesday by studying to post it on Reddit and that's when it kind of went viral so it didn't go viral immediately Wednesday I post it on reddit it got deleted for some reason well I didn't delete it but apparently I was violating some rule so it got and I I thought it's kind of over I said I'll try again next week but somehow I got picked up by a couple of sites and I tweeted out to hololens I tweeted out to Holland saying hey check out what I built never heard anything back from them and when went to sleep I woke up next morning and the video completely skyrocketed the tweet was now in like five thousand retweets and everybody across the internet was somehow talking about this thing right I woke up to thirty emails all asking for permission to use this and by the end of it it was covered in almost all major publications across the internet and from it was not only about recreating SuperMario in air right for me also it was about just generating this interest and getting conversation started and having people not only talk about what is possible now but what will possibly be possible five or six years from now and and that's what it kind of led to led to a lot of interesting conversations when people seeing is this the future of gaming is can AR now be used outdoors because that's something that has not been tried before can AR be used for fitness activities will these headset private it will will these large expansive outdoor experiences become the norm and many people are now questioning do now do I now have to deal with weird guys jumping around this place and not looking down at their phone they already got a taste of that way Pokemon go but except now you'll be with something probably mounted on your head and another thing that I always get asked a lot is what is my opinion on AR vs. we are I have worked with VR and I have worked or with AR personally my opinion is that AR has a lot more potential and ers possibly going to be a stepping stone maybe to VR and one of the main reasons that I feel they are is going to have much mass adoptions not only because a lot of companies are supporting it currently but more importantly is the user experience that it provides we are demands fully motion right it asks to cut you out of what you are doing you have to wear this headset you completely occluded from the world around you whereas a are just allows overlays it on to the real world so it it demands less effort from the user which is why I feel it's in better stepping-stone and a better stepping-stone rather than VR and that's basically about it so if you have any questions I would love to kind of take them now both those questions very often so it took me about a month to build it including building out the three the 3d assets and all those things it was not it was a sleepless month for living for the gallery and in addition to that if I'm going to build more games I'm not too sure I was thinking I might do maybe make another level of Super Mario one of the underground levels in the subway or something like that by the same thing there's been also like a lot of interest of like recreating like doom or one of the older older classic games but but I do have a feeling that there'll be a lot of developers who let's now start working on themselves yeah we are in action I have not yeah okay yeah okay oh great yeah yeah I have yes I haven't had a chance to play with it I don't have access to one yet yeah yep more real were you able to support this at all get a sense of where the light is coming from and you talked about like the strength of the line yeah you know to get like a shadow of the object or also to get like a little like a glare right on the surface of the object like so it doesn't know where environmental light is coming from but you can put programmatic lights which simulate the environment to give you those kind of reflections and glaze yeah yep it's a completely self-contained so the hololens has the power source inbuilt into it I have used it extensively and it lasts about maybe two two and a half hours which is not that bad yeah your kit I haven't started playing with a arcade yes because I don't have access to an iPhone so so yeah once again an iPhone or if someone gives me an iPhone hint came in then I will start playing with the orchid yes well multiplayer essentially I would have to dress up as Luigi and play the game again yep I think unity a treaty that the unity engine is amazing and you can do like a lot with it but at the same time perhaps the hololens documentation is not the best yet it's not put together yet though they do have a forum which is relatively active and they're quite helpful over there so it did require me to go to the forum several times and dig around in different places to get everything to work but unity itself is quite a mature platform okay I forgot completely I should have been repeating these questions so so he asked what is the computational intensive meanness of running these programs this was not computationally too intensive the Hollow Earth Harlan says that it can render up to hundred thousand polygons without any problem and especially in the case of Mario because it has this pixelated kind of boxy look so the assets themselves were not very heavy yeah so this ran without any problem yes he didn't intend to reach out to me after this is out no they haven't reached out to me yet a lot of people have said that they will only with the cease and desist so but that hasn't happened yet I I don't know if I'm happy I'm kind of bummed out but yes yeah so the question is unity has an option to suspend the laws of physics so I did play with that the the thing with AR as compared to VR is that AR still has the real world anchored around you so it doesn't create the illusion it doesn't create a good enough illusion to play with gravity because there are some suggestions that for me to climb up the pipes maybe I could lower the entire level as I was jumping but because I would my I would also be seeing the real world anchored where it is it would not be a good effect at all yeah yeah okay from my bio what have been my past businesses so one of them yes was related to VR and air it's called syrups around and essentially it is a platform to create and share live 360 of rented videos so you can take a 360 video 360 videos video that you can look around in all directions and it is captured with specific 3d cameras and we allow companies and brands to livestream a 360 distributed through a platform but at the same time augmented with elements so you can layer it with any kind of 3d objects 3d elements any kind of rich media images texts tweets websites and send it out to your consumers all right yeah would it be possible to use like 360 video to just film Central Park really well and then you know put it in in a VR situation where you have the element add-ons from your code and you have the 360 video and then anyone around the world so long as they have the 100 meters of straight flat yes can now see Central Park and can see the object so the question is how do you transport someone in who cannot go to Central Park into a vr thing is there some technique to maybe recreate Central Park in VR and then integrate this game into it so the problem capturing a 360 video is that 360 video does not have any depth so essentially it is just a sphere and you place the camera in the center of the sphere and look around in all directions so you would not be able to create the 110 meter depth what you could do is maybe do a really large photogrammetry capture of Central Park so photogrammetry is taking pictures of an object from multiple directions and then it uses that to kind of map and create an actual actual 3d representation of that thing so either a huge photogrammetry or capture or using something like a lidar sensor to recreate the entire space import that into a vr space and then integrate your Mario game into it yeah it's possible yes okay so uh applications of a are beyond videogames and possibly in educational space yes definitely I mean for education and that's where Microsoft also has been using the hololens a lot is educational spaces because and shared experiences I feel like in educational experiences being able to like share an education experience itself is really powerful so using them in classrooms using them to kind of their examples of interaction with the solar system right and you can't really interact with a solar system but you can take like a 3d representation of the solar system place it on the table have your students kind of stand around it look into it and then actually see how everything works or they similarly there are a lot of a lot of use cases in human anatomy and human anatomy and understanding the body is something which is really cool because you can actually take the body split it up into all its different subsections walk around interact with it and see all the different elements so so definitely education like the possibilities are endless in education all right okay looks like that is it [Applause]

Channel: CS50

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Length: 41min 45sec (2505 seconds)

Published: Fri Jul 07 2017