Unity3D GameDev Interview Questions

[@alexpanov4270]

I just got an interview and these are the questions I was asked: - what things to consider while working with canvas? - what is async/await? how is it different from coroutines? - what is Dipendency Injection? Give an example of DI usage. - give an example of S and O usage from SOLID in Unity. - what is assembly definition and how to use it? - how to use git. - how to optimize sprites? how to optimize particles? This looks like general knowledge that every jun to middle dev should know.

[@Ghost13-]

I don't even know a single answer XD

[@RP-dy5mu]

I have been working in game dev for about 3 years now + studying 2 years for it, and I could type out answers for most of these after thinking about it for a while. But jfc I would be totally devastated if I got asked some of these. I am really really bad at all this spontaneous stuff. 🙈

[@publicalias8172]

@@RP-dy5mu yeah truely.. Like these also sound super vague "things to keep in mind with canvas" If this wasn't a UI related job I'd end the interview straight up.

[@phunweng962]

I should feel ashamed? I'm already hired and I have cant answer them all

[@mora_tys]

well... I can answer the question about git 😕

[@Unity3dCollege]

Baby Yoda & the Crazy HammerBot stole my focus... :)

[@LordsofMedia]

Congratulations on 100K

[@felixsantana8043]

Congratulations on 100K

[@sorrowseal]

Manual focus.

[@LordsofMedia]

@@sorrowseal Ford Focus

[@modularwarmachines2028]

Congratulation Gandalf

[@АлексейКонстантинов-т3я]

Man, I'm going to my first interview tomorrow, your video is just on time!

[@yertok2900]

и как прошло собеседование ?

[@Metalvain4]

Thanks, Jason! Still relevant in 2024!

[@rodolfoc.nascimento6301]

Thanks man! You saved me a lot, well my Player was not give a good feedback in the keyboard, I've change the Fixed Timestep to 0.01 giving an 100 frames per second, now it looks smooth and it 's very responsive! Great!

[@meltysensei2652]

Excited to see the new game tutorial for Unity 2020! So many things have changed and the other 3 hour 'mad birds' was an absolute gem!

[@Unity3dCollege]

It's coming along great, have some sweet new art in the works for it too :) almost ready

[@iamDRW]

Great vid, json, I'd like to add some math ones that I've ran into a lot: How to find the direction vector from point A to point B? What is the dot product and the cross product? Give me some examples of them in games. When should you normalize a vector? How to find the angle between two vectors? How to determine if two circles are intersecting? And some optimization patterns: Data locality, Spatial Partition, Object Pooling. Pretty much the ones from the gameprogrammingpatterns book. You don't have to memorize them, but the one optimization topic that kept popping up is something like - there's a million spheres moving around and is hurting performance, what kind of optimization techniques would you do to help it perform better? I remember you put out a similar video like this last year and motivated me to start applying and going through that painful process of applying. I still keep getting denied but still trying! Hope this might help someone. Thanks again, json.

[@GiannyDev]

Without more info of what exactly you want to achieve, here are some answers, correct me someone if I'm wrong. 1) vectorA - vectorB or vectorB - vectorA depends on the dir you want 2) Dot product is the angle between 2 vectors, Cross product is the perpendicular angle between 2 vectors, both math functions are used in different situations. One simple example, when creating a CharacterController and you are facing slops, you use here the dot product to know the angle between the normal of the surface and the direction of your controller, if that angle is less than the max amount you set, you can go through that slop. 3) You should normalize a vector when you only need to know the direction towards something. 4) You can find the angle Between 2 vectors with multiple approaches, for example, use Mathf.Atan2(y,x) or Vector3.SignedAngle(vectorA, vectorB, face direction) 5) Object Pooling use it in any case where you need to instantiate multiple objects, you can reuse those with pooling. 6) Optimization is a big topic to explain here.

[@RasTaIARI]

@@GiannyDev The question was clearly stated as from A to be - so its B - A

[@aaronalfer2615]

I think you should be specific with terms. Dot is not an angle, it's not measured in radian or degrees, it's the cosine of the angle between 2 vectors times their magnitudes. So for normalized vectors its value ranges from -1 to 1. Cross is not only not an angle, it's a whole new vector perpendicular to the other 2 vectors, and it also has a magnitude which is sine times the magnitudes. So there are more things you can determine by these functions than just angular relation. For example, even if you have 2 vectors pointing in the same direction, you can use Dot to determine, let's say, combined force applied in that direction. And many other things :)

[@iamDRW]

@@GiannyDev I'd say your answers seems fine to me. Others have stated some specifics to be sure of that are good to know as well. Aaron has a good answer about the dot/cross product. I'd like to note that whenever I was asked the angle between 2 vectors, I would have to work that out by doing some algebra using the dot product formula. Let me know if you need to know how to derive it. Assume you don't have a library at hand. I had to work out the math on paper, which isn't too bad. Remembering the dot/cross product in math form to computation form helped me out a lot. I'd like to also add: How do you normalize a vector? How do you find the distance between two points? Is there a way to make it faster if we are only comparing which is closer? Optimization is definitely a big topic. But the "there's a billion of 'X' - what steps you do to help it run better" always came up. I forgot to state these questions were asked at both junior level and mid level gameplay engineering interviews.

[@CharlieScarver]

Thanks for sharing these! 🙏

[@F3ND1MUS]

Jason is really good at what he does, I love it, thank you J!

[@iangraham6730]

I swear, a month ago you looked on the verge of retirement, and possibly buying a time share in a beige motorhome . . Today, you look like a man thats prepared to drop a bomb on the dance floor and show those cross town boys that daddy's in home! Either way, top class Tut as always! Thanks for sharing Jason 👌👍🏼

[@chiefmofo]

Having been on a lot tech interviews and having given a lot, you mentioned one of the key things you should do for almost any question, and that's get more context. I've spoken with so many other interviewers and trainers who will deliberately ask a super vague question that cannot be answered correctly without the candidate asking clarifying questions. And even if the question is straightforward, what's really impressive is if you give several examples in different contexts.

[@mrp0001]

Hey Jason, in your video you've asked for some recommendations so from my side, I'd love you to make more content on DOTS please :) You're an amazing teacher and seeing you covering the subject would be great.

[@gideoncresswell]

Another quality video thanks! I've learned so much from these recently - far more than from any other Unity videos online.

[@logerz]

Great video as always Jason! I started watching your videos about 4 months ago, when I decided to pursue my passion and you've been helpful ever since. Can't wait for the "How to make a game 2020" tutorial, keep up the good work sir!

[@eusebiuionut7646]

I really like your videos. dont stop the greate work. As an intermediate dev i would like to see a video focused on architecture. e.g. scenemanagment and gameplay flow because every video i see out there everything is tightly coupled

[@kippenegg]

Agree with your suggestion!

[@benvella1728]

Without over engineering the beejezus out of your game, some coupling is typically desired. Having some object that allows direct references to common systems is something most games I've worked on have. The exception from what I've seen are very simple versions that allow things to run on the fly, all scenes can be independently launched. Arguably the same decoupled approach can be kept but when designers come in and pitch a whole new idea out of bumfuck nowhere, that's where the sweating begins when you have to consider how much more work it is to wire in a new system when everything else just floats about, and needs to be passed in through the editor or will require a dedicated chunk of work to get a working version of it. Things like analystics, backend systems etc are usually kept easily accessible and not allowed to repeat (singleton approach). Haven't thought of a better way yet but always open to suggestions

[@nathanistace3353]

Congrats for your 100k subscribers. I've been watching you for a while now, and think you absolutly deserve it! Keep up the great work

[@fumetsuhito5561]

Jason I wanted to let you know that I consider you my mentor in game development (programming side) I learned a lot of concepts from you on how to think about Architecture and yet again I learned something new, the Json Serialization will make my saving logic more tidy and efficient

[@sanjithwalker6041]

Hey buddy Are you a game programmer?

[@simoncodrington]

Congrats on the 100k subscribers mate, well deserved for sure :) Been great watching your content and seeing how its evolved over time.

[@Oxmond]

Cool. Congrats with the 100K subs Jason! 👍🤓🧡

[@Treetopper911]

Thanks for the new Video, Jason! Love your videos. I look forward to new developments from you.

[@takashy87]

I've been trying to get a Unity job for a while and so far I don't remember ever getting any Unity related questions during interviews . At least not in terms of the examples given in this video. Usually they're more general , if they even happen at all. I haven't had that many interviews for Unity positions, but from my experience they usually go 2~3 ways: - go over your background and maybe your Unity experience in general (personal projects only in my case) followed by a test - go straight into a Test without even bothering to have a call before it With the tests being the important part. Since I'm applying for a programmer position, usually the tests are mainly about writing good / clean code (sticking to SOLID and some patterns) and showing that you know your Unity stuff (like the things mentioned in this video). The tests usually end up being about making some kind of simple game or clone of an existing one., mainly just to get some code down that the company can check out (unless you already have some code you can share, I guess) Though it also seems to depend a bit on the type of games the company makes. Mobile game companies usually seem to focus just on code quality and knowledge, while the companies that work on PC / console games seem to be more interested in more technical / mathematical knowledge that are relevant to the games they make, rather than just being able to write good code.

[@AliAzizQualityEducation]

latest game developer interview tip : kzbin.info/www/bejne/f4W4oaiBl6mBic0

[@auroranova]

Another way to describe coroutines that I think explains how they work a little more: The single thread is passed from coroutine to coroutine amongst all active game objects in the scene, and the thread executes each coroutine up until the next yield statement. Then, the thread is passed to the next coroutine, etc. And it loops back around until all logic in all coroutines that need to be handled in any given frame have their logic executed. In doing so, each object has its behaviors expressed in an order that the human eye perceives them all happening at the exact same moment. So it tricks the human eye into thinking this is all asynchronous.

[@nichegames9590]

I love the office setup. THanks for the video.

[@Unity3dCollege]

Thanks!

[@bitbrain3468]

Pretty helpful. I think I got asked that update/fixedupdate question in my only unity/gamedev interview ever (so far, #2 in 1.5 hours, hopefully I have better luck this time).

[@publicalias8172]

How'd it go? Please share your experience good or bad!

[@riteshkhokhani]

very useful information, one of best video for unity interview questions

[@mthew6721]

Super excited for the "make a game" video, been going through the angry birds clone and wanting something different. Thanks for the content!

[@CodemasterJamal]

Congrats on 100K subs!

[@Alzimovich2]

Nice vid Jason! :D Just a little correction: in C# the % operator is the remainder operator, not the mod operator. The difference is slight, but for instance -1 % 10 will return -1, not 9 as you would expect from the mod operator.

[@aryanasdf3424]

Jason i think you should get your youtube channel verified, it will attract more people, and i love the way you teach, cheers

[@Francisco-Gutierrez]

Congrats for the 100k subs!

[@samojitde2419]

So many questions were there which Jason solved for me.....I love it😃😃😄

[@jake-ly]

The question we always ask at my work is "what are singletons, and why would you use/not use them vs similar methods?"

[@justinriccardo6634]

A question I was recently asked is what is the order of calls that happen when a game starts to when it ends. So example is its OnAwake()->OnEnable()-> Update()...ect.

[@dudenarima2528]

It's also important not to just give an answer, but also show them ur thinking process. Just say everything you have in mind, like "If I do this, this will happen, so It'll break the system. But if I do this..."

[@publicalias8172]

That makes sense.. Though sometimes it can give a false impression someone doesn't get something just because while they may be a genius programmer they struggle with deconstructing their thought process Verbally its two completely seperate skills.

[@andythedishwasher1117]

1/timestep = fps. Storing that in my formula database for damn sure.

[@alexsevilla5389]

Congrats on 100k 🥳

[@-will-1389]

100k! Well done!

[@addikins3082]

Would love to see the Office Tour video.

[@zekiozdemir420]

You are my HERO.

[@praveshsharma9194]

You r doing great job👍👍👍

[@thelowendstudio]

This is a really helpful video🔥 thanks Jason ❤️

[@supertenchoo4271]

Very Informative this kind of video is very helpful thanks so much

[@youtubechannel548]

I'm a bit late but congrats for 100k subs man!

[@tmoneygamestudio]

Congrats on 100k

[@0darkwings0]

Hi 👋🏼 can you elaborate more about coroutines? Maybe with examples, when we should use them and more importantly when we shouldn’t use them

[@yomamasofat413]

Okay so for fixedUpdate vs Update, both are just loops but for fixedUpdate it runs at a fixed time at every 0.02 seconds (default) and you want to do physics things like add a force every standard amount of time and also so that you dont add it more frequently in the Update method. The Update method loops quicker usually

[@mogacreative409]

Congrats 100K!

[@riteshkhokhani]

very well explained in detail

[@ejhessing]

Hi Jason, cheers for all your videos. As a web developer looking at game developer as a possible career move, are you able to please go over what a typical day looks like as a game dev in a team? I would imagine as an Indie dev you would spend most of your time designing your game in terms of what objects look like, how they move etc and much less of your time on the scripts. How does this compare to working in a team with game designers, 3d modellers etc.

[@zainjavaid7659]

Thank you for the information.

[@AliAzizQualityEducation]

latest game developer interview tip : kzbin.info/www/bejne/f4W4oaiBl6mBic0

[@amidofulue6205]

I was asked about the difference between Start and Awake, and the difference between Update and LateUpdate

[@abdullah4653]

awesome tutorial man

[@y01cu_yt]

Thanks Jason.

[@raveltammeleht6278]

nice Tupac Shakur reference in the background ;)

[@RasTaIARI]

FixedUpdate vs. Update leads me to this random semi-related comment: The convention about the game-programming community that so much should happen within update loops in general is something that always struck me as bad software engineering. Input should just not happen in update. Repeatedly querying boolean values in a loop is simply an ugly practize. An input event is an event. Handlers should be attached to events. The idea that a key-down variable is true for the duration of one frame - its a bad one. Also I like the async-await syntax better than coroutines. coroutines are basically a syntactic hack, to use the power of enumerators to do the context-switching. from a language point of view, its clear that Tasks were really designed for this.

[@kingjr999]

Your my replacement for Brackeys

[@ghost5hadow315]

Not a replacement! Jason comes after you've completed brakeys tutorials ☺️

[@shubhamthakare295]

He's not replacement , Jason is jason he's Alpha and Omega

[@titkosaaron4067]

brackeys was a dlc of jason, u just played the dlc first

[@Flick69ED]

Brackey himself suggested him

[@teh1archon]

I had a series of interviews last week. Design patterns and SOLID principles were a big chunk of these. But I was interviewed for a senior position so... Idouno how much to know these for junior positions is relevant but in my country DP are always asked no matter the level of the position.

[@PPLorux]

Hi Jason! I would to to see a video where you do a quick postmortem of the commercial games you worked on. Thank you, have a nice day!

[@claudiosilvestri8485]

From version 3.0 to version 4.5 of Unity is it possible to use only the 2012 version of Visual Studio professional ?

[@tarrocan]

i really like your content, maybe u can make a Video about level Design and some tips do use texture , prefabs etc. would be really nice do see how u would do start Level Design especially preparation :)

[@ArcadeMdns]

Unity documentation says FixedUpdate is frame-independent. Always. If game fps drops below, it shouldn't affect fixedUpdate call frequency. Am I wrong? For example Thread.Sleep(50) in Update make my scene to run slower and I get from 2 to 4 fixedUpdate calls each frame.

[@ashtwenty12]

Congrats on 100k. Have you decided what game you will fully make. Can I suggest something with tilemap please, and finite state machine AI

[@tigranavagyan1587]

Thank you!!!

[@adityashanbhag5044]

Great Video Jason. Have one question though, @22:18, Is it possible to store image/sprite in WritePlayerDataWithJson() ?

[@publicalias8172]

Doubt you'll get an answer. I would suggest you to write the bytes of the image and reconstruct it into said image when needed.

[@Gaisiran]

Making a game sounds like a good idea

[@hank_bloodshadow]

i less or equal to _max otherwise it just goes to 99 :) Last print should be Buzz (100).

[@twiconst9137]

can you explain about unity mobile game development? i was asking this for a long time. I am also using your website.

[@pagames3d]

Hello Jason, for about 4 days I see blue circle that indicates that you uploaded new video, but nothing new. After I visit your channel page circle done, but in few hours appears again.

[@JKczolg]

can you make video about what is a "good for me"(i mean you ofc) system to build, like you did with kids game. Like a simple quest system. would greatly helpfull

[@Woewal]

What is your opinion on using Scriptable objects as a replacement of singletons?

[@apritellolives3920]

What do you know about coroutines? I don't like them I prefer Task

[@nemogames5354]

that's fuckin it??? im definitely applying

[@zainulabdin2614]

Is there any way we can practice coding specifically related to unity? If there is any helping material or website kindly do let me know

[@random_precision_software]

Hey Jason, have you come across the UNITY DISTRIBUTION PORTAL? It puts your games on sites like SAMSUNG, HUAWEI, etc, without you doing it for each site. I'm having trouble uploading my game it crashes..ANY chance you'll do a video on it

[@miriomandubisi4593]

Pls show is a tutorial on how we can receive payment from Unity

[@vladimirkuznetsov3601]

4:12 this is not correct. The FixedUpdate rate can easily be higher than game's framerate. It will stack multiple calls in between Updates simulating higher rate.

[@phunweng962]

Can you explain? while Jason literally just simulate it out to prove his point.

[@vladimirkuznetsov3601]

@@phunweng962 he demonstrates that FixedUpdate can run slower than Update on high FPS, but it also can run faster on low FPS. Search for "Order of execution for event functions" - Unity has a good article about it with a flowchart. Here is a bit from this article: "FixedUpdate: FixedUpdate is often called more frequently than Update. It can be called multiple times per frame, if the frame rate is low and it may not be called between frames at all if the frame rate is high."

[@vladimirkuznetsov3601]

Although he is correct that FixedUpdate frequency can drop, this only happens if FPS delta time is higher than Maximum allowed timestep. Until then Unity will call FixedUpdate as many times as it needs to keep the simulation frequency.

[@phunweng962]

@@vladimirkuznetsov3601 I got you. I have a pretty good pc and I assume Jason does too so I can barely imagine potato that will run FixedUpdate more frequent than Update.

[@neox9235]

cool i like your content

[@willianaraujodesouza6940]

Hello Gamedev.tv, could you help me pfv ? in my project has a ball with an arrow directional, as I do for the Ball shoot only in the direction that the "tip" of the arrow is aiming please. i put a gameobject with collisor on tip ^^,

[@epath4957]

Have you ever met a god game dev who learned by himself with online courses? I started to learn C# last week, of course I know nothing but I've seen a couple interview videos and pages and I got to say all of them scared me af. Hell, I don't even know if I'll like programming, so I might find out I don't and be done with it, but even if I do end up liking it idk, seems too much more than I could learn from online courses tbh.

[@Unity3dCollege]

I mostly learned from a few terribly old books, experimenting, and stumbling through real projects. Now I go to videos and courses woth blog posts for some specific topics amd ofnc I urse online docs when they're good :)

[@epath4957]

@@Unity3dCollege I see, thank you very much for your answer! I'm downloading Unity tonight, and maybe in a couple weeks, I'll be certain I want this path (or not).

[@TealKeel185]

I got asked about linked lists and matrices in an interview and apparently didn't get the job because I don't use them? Are they really that important in Unity or something that would be integral to be working with Unity?

[@Unity3dCollege]

Matrices yes, linked lists no.. at least not in unity. And the matrix work you need to do depends a lot on the role. Most devs don't need to worry about them day to day, until a specific issue pops up. Gfx programmers need to be matrix wizards :)

[@TealKeel185]

@@Unity3dCollege I really appreciate the response! And thanks for the video. It's hard to figure out what I can do to improve my employability without knowing what is expected. Saying "We want 3+ years of Unity Experience" isn't very helpful. Thank goodness for peeps like you!

[@THEspindoctor84]

since you asked about other videos to make, and I heard in another one of your videos that you aren't much of an artist....how do you deal with that? As a solo developer, what's your process on getting your games completed if you aren't much of an artist?

[@publicalias8172]

Paying for commission work is a popular route people go.

[@xingorro8605]

Tour would be nice,.

[@zeeshanqaswar3573]

Why did you came back to Visual studio from Rider???

[@Unity3dCollege]

Tutorials. I use rider for more advanced stuff and my personal projects still :)

[@nenadkis5015]

Bro try fixed game Dark Nemesis please

[@SukruBeyy]

First of all sorry for my bad english , I'm living in Turkey. I am a student of Mehmet Akif Ersoy University CTIS department. I want to do an internship abroad. That's why i am still learning english. Do you think it is impossible ?

[@publicalias8172]

Nothing is impossible for those that try.

[@JarlThorson]

I thought PlayerPrefs were stored in the Windows registry.....this seems a bit rude to our players to use. Or is that just me?

[@SinusQuell_]

As far as I know PlayerPrefs are in AppData on Windows, no?

[@JarlThorson]

@@SinusQuell_ According to the docs: "On Windows, PlayerPrefs are stored in the registry under HKCU\Software\[company name]\[product name] key, where company and product names are the names set up in Project Settings." docs.unity3d.com/ScriptReference/PlayerPrefs.html

[@SinusQuell_]

@@JarlThorson Wow, then I agree with OP, that's kind of rude :o

[@jonduan5718]

Thats why i love internet, includes a lot of information and bikini videos

[@publicalias8172]

W h a t

[@royalstudio7113]

Number

[@Т1000-м1и]

1 week ago

[@YAS-vm8ko]

Json

[@hossein818]

I think you can make fizz buzz more better with a variable and 2 if and a debug. string a = ""; for (int i = 1; i

[@aleyummusic]

Oh if only Fizzbuzz was asked and not crazy LC problems

[@royalstudio7113]

Hallo

[@royalstudio7113]

Hall

[@geri4367]

Don't quite like the new content. I started following like 3 years back when it was all about game arquitecture and programming patterns. Now that I have 3 extra years of experience it's all about suuuuuper basic stuff :(

[@EvansdiAl]

tough luck

[@kippenegg]

tough luck

[@ikryper]

Seek Jesus Christ, he will open your eyes to the truth. He is real

[@ZuoCruz]

Amen

[@fearlessjet]

Seek a suitable comments section.

[@publicalias8172]

@@fearlessjet anime