I was reading about this for a year and didn't understand it well. With your 7 min tutorial you gave me much better understanding. Thank you very much Sebastian Lague.
Thank you so much for making these videos. As someone just learning game development focusing on programming, there is a lot of simplistic and outdated stuff out there that wastes your time. I don't need a step-by-step tutorial on how to make a dinky little game no one will care about - I need to know how to *think* about this stuff, how to *approach* it in a more general sense. Can't wait to get through the rest of the series.
oof i am feeling confused about this one, but it's the kind of confusion where it feels like being confused is doing something- it just needs time to gather and i need to find some more examples. thank you for these lovely, extremely well-made videos!
I already knew this stuff but once again I have to praise the clarity of the explanation, much like your neural network video. This makes it crystal clear and if I need to explain this to anyone, I have somewhere to point them to now, thanks
I managed to solve an issue I was having (unless I later find an issue with it) using knowledge of how reference/value types work from this video, so thanks for giving a proper understanding of what these types are.
Is there no distinction between the stack and heap in C#? As far as performance is concerned there's something to be said about optimizations that can be made by allocating memory either on the stack or heap, which is very relevant to game programing.
For resource management, would it be effective in the case of this example, to check if a point has the exact same values and rather than create a new point with the same values, reference the point that has the desired values? Or would the performance loss of looking for a point stored with that value outweigh any possible gains? All of this is assuming that all points values will remain constant and never change. I've been programming for several years self taught with Lua and now learning C# has introduced me to some seriously different standards. You're videos have been a great asset to me. I realize these videos are fairly old, however I was also wondering, if you are still creating content, if you would do an in-depth review on programming shaders in unity? I know we have a shader graph now, but the code actually seems easier to understand for me.
VERY USEFUL TUTORIAL! Thanks! I've been trying to understand what struts are and the difference between reference and value types for the longest. One question though... how are constructors different from structs?
A constructor is just a way of setting the values inside a struct or a class when a new object is created. So constructors aren't "different" from structs, they're a part of structs (as well as classes).
Hey Sebastian, so Point a = new Point (2, 5) creates a new object in ram. Then what happens if I do a = new Point (2,5) again? The previous object in ram is till in there? Like, if I do a = newPoint (2,5) like 100 times, will 99 objects of Point be kept in ram without being used? Is that an issue?
The problem I have is knowing how unity declares it as struct or class. Transform could be used as a struct more than a class for me at least but its a class in unity. I think C++ pointers make it more clear in terms of whats being referenced and whats being copied
Hi Sebastian, Wanna add that list elements and array elements behave as reference types when stored in structs however list and array itself behaves as value type like i can modify any element of array/list stored in struct but could not replace the whole array list/array. someStructObject.array = new int[]{1, 2, 3}//this does not have any effect on someStructObject; someStructObject.array[0] = 5;//this updates the first element of someStructObject array to 5. Read the comments in code. public class Test : MonoBehaviour { void Start() { MeshTris m = new MeshTris(new int[] { 1, 2, 3 }); RunTest(m); // Here m is modified and new values of m are 4, 2, 3 } void RunTest(MeshTris meshTris) { meshTris.tris[0] = 4;; } } public struct MeshTris { public int[] tris; public MeshTris(int[] tris) { this.tris = tris; } }
This is why I really wish more high-level languages did references under the same sort of semantics and syntax as pointers in C. The problem with making reference semantics so implicit is the fact it's so stupidly easy to introduce bugs into code because the language is all too happy to make things a reference and not tell the programmer. In my opinion a well-designed language will always default to values and never ever implicitly switch to reference semantics without the programmer explicitly invoking them. This is why C succeeds in so many places C# fails. For example, in C# you can do Point p = new Point(5, 10); and C# will do it without complaint. In C++, you'd get an error because you're trying to instantiate an object on the heap and then assign its address to something that is NOT a pointer. The compiler would reject the code and tell you this. It should be Point *p = new Point(5, 10); The * there makes it clear in the code that you're working with a pointer. The programmer EXPLICITLY invokes something like a reference instead of the language sneakily invoking a reference on the programmer behind their back. Yes, pointers can be confusing, but they're probably the source of a LOT less hard-to-find bugs than implicit references. And yes, C++ does actually have a non-pointer reference semantic, but AGAIN, it requires that the programmer explicitly invokes them, and when the actual reference itself is used, the effects fall back to acting like you're acting by value. You pass things by reference into a function in C++, but you're not stuck dereferencing anything to work with it, and when you actually assign from something passed by reference, you're still invoking the expected copy semantics. It does have the side effect of introducing side-effects, though, since passing by reference means you're not working with a copy of an object when you pass it into a function, so if you change the object passed by reference in a function it'll be changed in the caller function as well, which is why in C++ you'll most frequently see references being passed into functions as const, so that the object cannot be changed by the called function. But, as much as I like Python and work with it, I'm not a fan of languages that assume it's safe to go into reference semantics without the programmer making that clear on their own. It's weird to me classes and structs are supposed to be the distinguishing factor in C#.
For anybody: What's a quick example of what one could use structs for? I've never personally had to use one and, judging by the way they behave, I wouldn't necessarily want to use one for fear of losing track of what a variable is supposed to be doing.
@@mhhm-mq3ct Fair enough. I guess I wasn't referring to those structs. I was more or less looking for examples in which one would go "Hey, I don't need a class right now/ a class is just too much/ doesn't suit the task at hand, I need a struct." Like, specifically, when you could use a class, why would one forego it for a struct instead? That's more or less what I was trying to ask. I probably wasn't being clear, I'm kind of new to all of this, but floats and bools and stuff kind of misses the point of the question I was trying to ask. "If you would watch carefully" Well, I did. Multiple times, in fact. So.. .... Why the attitude sir? You initially come off to me as bitter. Why are you mad? I ask because you seem to assume I didn't watch this 5 times beginning to end already, and it kind of pisses me off you felt the need to begin your comment with this incorrect assumption that I didn't already watch this fully well before posting, or wasn't willing to "watch carefully".
hi its me pie again. I imported the 3d model I made into unity and for some reason the colors only show up when I look at the model from underneath it or through the side of one of the bumps in the map. I imported the model in an fbx file and I was wondering if i was supposed to. is there a way for me to send you screenshots of the problem so you can see yourself? thank you
Those are "custom" data types created by the IDE or API,.. on different Systems an int may use e.g. 4 Bytes (32Bit), 8 Bytes (64Bit) or only 2 Bytes. This is specific to the target system. By using uint32 your unsigned int will reliable use 4 Bytes
And why do both methods and structs have to exist? what are the pros of each over the other?It seems to me that structs make more sense. OOOOh, do structs not have parameters? And that's why we need methods as well?
What my computer science is trying to learn us since 2 months lol. Thanks, i did'nt knew what object.method was meaning in visual studio. Fun fact: I have an exam on it today. Thanks!
Hey Sebastian Lague i am learning a lot from your video.Thank you very much Recently i completed you 2d platformer series.And I have also implemented climbing,swimming,shooting,pushing,dashing,player underairforce,jetpack,crouching and also enemy AI ,created an animator to handle all animation can i sell that asset on unity asset store for 5$ only with your permission
@@Arbeta10000 Well his question was if there was other people confused by this, not a question with which answer he can help himself, but instead comfort himself that there are other people who are confused as well. So. just type "Omigod, yes, I am also confused", and that will help him a lot! lol...
@@Ggd07 That's not a useful question to ask though, if they want comfort then the internet is the last place for them to go, because it's full of people who will do the opposite as well. xD I'm not one of those, mind, but the real question in Araraura's comment seemed to be "could somebody help me understand this?", at least from the way it's phrased. If you went up to a teacher and said "I'm confused by this" then it'd be a bit unnatural for the teacher to say "I'm not" or "me too". They'd assume that their sentence was meant as a question.
Unfortunately this was the first video to completely lose me. It was WAY too abstract for me to follow. I struggle to follow things that aren't accompanied by something demonstrating *why* I would be using the demonstrated method. As in, an actual program (even if super simple) with a tangible task. Simply seeing all those letters didn't make a lick of sense to me :-/ heading into the next tutorial and hoping that's where it will all make sense.
You should be awarded for these concise yet really helpful masterclasses!
Agreed. These are far more clear than many of the official Unity videos.
Well, there you go. 1 1/2 years of computer science before this was cleared up.
I was reading about this for a year and didn't understand it well. With your 7 min tutorial you gave me much better understanding. Thank you very much Sebastian Lague.
It's 2020 and these videos are very useful to start with Unity.
Thank you so much for making these videos. As someone just learning game development focusing on programming, there is a lot of simplistic and outdated stuff out there that wastes your time. I don't need a step-by-step tutorial on how to make a dinky little game no one will care about - I need to know how to *think* about this stuff, how to *approach* it in a more general sense. Can't wait to get through the rest of the series.
oof i am feeling confused about this one, but it's the kind of confusion where it feels like being confused is doing something- it just needs time to gather and i need to find some more examples. thank you for these lovely, extremely well-made videos!
I already knew this stuff but once again I have to praise the clarity of the explanation, much like your neural network video. This makes it crystal clear and if I need to explain this to anyone, I have somewhere to point them to now, thanks
FINALLY. THANK YOU JESUS! i mean THANK YOU SEBASTIAN!
Mr Fox OMG YESSSS!!!
I don't know if you still read these comments but this series is insanly good. Thank you very much :)
Your each and every word is golden in this video!. Couldn't be explained any better than this.
Found this out the hard way whilst writing trying to manipulate lists in python a few years back. Thanks for this.
Amazing stuff! Finally all my programming doubts are cleared. Thank you so much!
I managed to solve an issue I was having (unless I later find an issue with it) using knowledge of how reference/value types work from this video, so thanks for giving a proper understanding of what these types are.
2:10 interesting note to take: if you will test the following:
(a.x == b.x)
(a.y == b.y)
these will both be true :) while a ≠ b
Because x and y are value types and their equality depends on the value itself not the reference
Faz apenas 3 dias que estou assistindo esse cara e já quero assinar o patreon dele, mds, que homem
oh gosh, that helped me a lot & saved may hours of confusion! Thanks!
holy f*ck that's clarity. thank you baby jesus for your videos
Is there no distinction between the stack and heap in C#? As far as performance is concerned there's something to be said about optimizations that can be made by allocating memory either on the stack or heap, which is very relevant to game programing.
Superb explanation, as always!
That's great, Structs have been confusing me and this cleared things up for me quite a bit.
Dude, incredible video, and worth for more than games, thx you so much!!
Best tutorial about basics of unity. really recommend watching all his videos.
Excellent video. Thanks, Sebastian!
Thank you! In your next Intro to Game Dev episode, please consider covering Properties and Accessors
VERY good visualizations. Ty so much!
For resource management, would it be effective in the case of this example, to check if a point has the exact same values and rather than create a new point with the same values, reference the point that has the desired values? Or would the performance loss of looking for a point stored with that value outweigh any possible gains? All of this is assuming that all points values will remain constant and never change.
I've been programming for several years self taught with Lua and now learning C# has introduced me to some seriously different standards. You're videos have been a great asset to me.
I realize these videos are fairly old, however I was also wondering, if you are still creating content, if you would do an in-depth review on programming shaders in unity? I know we have a shader graph now, but the code actually seems easier to understand for me.
good stuff, is there any tutorial explaining the = ~ or = ( x
VERY USEFUL TUTORIAL! Thanks! I've been trying to understand what struts are and the difference between reference and value types for the longest. One question though... how are constructors different from structs?
A constructor is just a way of setting the values inside a struct or a class when a new object is created. So constructors aren't "different" from structs, they're a part of structs (as well as classes).
Thanks!! You're the best!
Hey Sebastian, so Point a = new Point (2, 5) creates a new object in ram.
Then what happens if I do a = new Point (2,5) again?
The previous object in ram is till in there?
Like, if I do a = newPoint (2,5) like 100 times, will 99 objects of Point be kept in ram without being used? Is that an issue?
If we have out, why do we need ref?
Whoa, so THAT'S what structs are for! Thanks. Maybe you should have mentioned pass by value though.
The problem I have is knowing how unity declares it as struct or class. Transform could be used as a struct more than a class for me at least but its a class in unity. I think C++ pointers make it more clear in terms of whats being referenced and whats being copied
Awesome Video you should make a series out of this.
Darwin Willers great idea. Then he could do reference vs value types in...
EPISODE 17.
Hi Sebastian,
Wanna add that list elements and array elements behave as reference types when stored in structs however list and array itself behaves as value type like i can modify any element of array/list stored in struct but could not replace the whole array list/array.
someStructObject.array = new int[]{1, 2, 3}//this does not have any effect on someStructObject;
someStructObject.array[0] = 5;//this updates the first element of someStructObject array to 5.
Read the comments in code.
public class Test : MonoBehaviour
{
void Start()
{
MeshTris m = new MeshTris(new int[] { 1, 2, 3 });
RunTest(m);
// Here m is modified and new values of m are 4, 2, 3
}
void RunTest(MeshTris meshTris)
{
meshTris.tris[0] = 4;;
}
}
public struct MeshTris
{
public int[] tris;
public MeshTris(int[] tris)
{
this.tris = tris;
}
}
Java needs structs, also, amazing tutorial
This is why I really wish more high-level languages did references under the same sort of semantics and syntax as pointers in C.
The problem with making reference semantics so implicit is the fact it's so stupidly easy to introduce bugs into code because the language is all too happy to make things a reference and not tell the programmer.
In my opinion a well-designed language will always default to values and never ever implicitly switch to reference semantics without the programmer explicitly invoking them.
This is why C succeeds in so many places C# fails.
For example, in C# you can do Point p = new Point(5, 10); and C# will do it without complaint.
In C++, you'd get an error because you're trying to instantiate an object on the heap and then assign its address to something that is NOT a pointer. The compiler would reject the code and tell you this.
It should be Point *p = new Point(5, 10); The * there makes it clear in the code that you're working with a pointer. The programmer EXPLICITLY invokes something like a reference instead of the language sneakily invoking a reference on the programmer behind their back.
Yes, pointers can be confusing, but they're probably the source of a LOT less hard-to-find bugs than implicit references.
And yes, C++ does actually have a non-pointer reference semantic, but AGAIN, it requires that the programmer explicitly invokes them, and when the actual reference itself is used, the effects fall back to acting like you're acting by value. You pass things by reference into a function in C++, but you're not stuck dereferencing anything to work with it, and when you actually assign from something passed by reference, you're still invoking the expected copy semantics.
It does have the side effect of introducing side-effects, though, since passing by reference means you're not working with a copy of an object when you pass it into a function, so if you change the object passed by reference in a function it'll be changed in the caller function as well, which is why in C++ you'll most frequently see references being passed into functions as const, so that the object cannot be changed by the called function.
But, as much as I like Python and work with it, I'm not a fan of languages that assume it's safe to go into reference semantics without the programmer making that clear on their own. It's weird to me classes and structs are supposed to be the distinguishing factor in C#.
You definitely should consider making Monogame series... tutoring can't be any neater than this.
Very useful, thanks :)
If reference types can't be equal to each other without referencing the same point in ram, how come you can check if Vector3s are equal to each other?
Vector3s are value types not reference types, so it just checks if xyz are the same for both
thank you that was epic
For anybody: What's a quick example of what one could use structs for? I've never personally had to use one and, judging by the way they behave, I wouldn't necessarily want to use one for fear of losing track of what a variable is supposed to be doing.
if you would watch carefully, he explained that almost all in-built types are structs ... if you ever use float, bool, then you have used structs.
@@mhhm-mq3ct Fair enough. I guess I wasn't referring to those structs. I was more or less looking for examples in which one would go "Hey, I don't need a class right now/ a class is just too much/ doesn't suit the task at hand, I need a struct." Like, specifically, when you could use a class, why would one forego it for a struct instead? That's more or less what I was trying to ask. I probably wasn't being clear, I'm kind of new to all of this, but floats and bools and stuff kind of misses the point of the question I was trying to ask.
"If you would watch carefully" Well, I did. Multiple times, in fact. So..
.... Why the attitude sir? You initially come off to me as bitter. Why are you mad? I ask because you seem to assume I didn't watch this 5 times beginning to end already, and it kind of pisses me off you felt the need to begin your comment with this incorrect assumption that I didn't already watch this fully well before posting, or wasn't willing to "watch carefully".
hi its me pie again. I imported the 3d model I made into unity and for some reason the colors only show up when I look at the model from underneath it or through the side of one of the bumps in the map. I imported the model in an fbx file and I was wondering if i was supposed to. is there a way for me to send you screenshots of the problem so you can see yourself? thank you
Sounds like your normals are flipped. should be able to fix this fairly easily in whatever modelling software you are using.
Zaphod BeebIebrox thanks but how do I flip the normals
Zaphod BeebIebrox I'm using blender
In blender I think it's just ctrl +N in edit mode, should recalculate normals.
Zaphod BeebIebrox k
Could you make a tutorial that explains what an uint32 is and why we would want to use it?
Those are "custom" data types created by the IDE or API,.. on different Systems an int may use e.g. 4 Bytes (32Bit), 8 Bytes (64Bit) or only 2 Bytes. This is specific to the target system.
By using uint32 your unsigned int will reliable use 4 Bytes
I must say that before you I hated C#. Now I actually like it a little bit.
THANK YOU!!!
And why do both methods and structs have to exist? what are the pros of each over the other?It seems to me that structs make more sense. OOOOh, do structs not have parameters? And that's why we need methods as well?
Thank you
Cheers
What my computer science is trying to learn us since 2 months lol.
Thanks, i did'nt knew what object.method was meaning in visual studio.
Fun fact: I have an exam on it today.
Thanks!
I hope it's not an English exam...
@@ChopChopMinecraft lmao
I mean, at least it is understandable.
nice!
7 minutes passed so quick
Hey Sebastian Lague i am learning a lot from your video.Thank you very much
Recently i completed you 2d platformer series.And I have also implemented climbing,swimming,shooting,pushing,dashing,player underairforce,jetpack,crouching and also enemy AI ,created an animator to handle all animation can i sell that asset on unity asset store for 5$ only with your permission
Am I the only one confused by this?
everyone here seem to understand this, but this is confusing af for me
Could start by asking questions, nobody can help you if you don't state the problem
@@Arbeta10000 Well his question was if there was other people confused by this, not a question with which answer he can help himself, but instead comfort himself that there are other people who are confused as well. So. just type "Omigod, yes, I am also confused", and that will help him a lot! lol...
@@Ggd07 That's not a useful question to ask though, if they want comfort then the internet is the last place for them to go, because it's full of people who will do the opposite as well. xD
I'm not one of those, mind, but the real question in Araraura's comment seemed to be "could somebody help me understand this?", at least from the way it's phrased.
If you went up to a teacher and said "I'm confused by this" then it'd be a bit unnatural for the teacher to say "I'm not" or "me too". They'd assume that their sentence was meant as a question.
this is free btw
finally........
im sorry sebastain but i dont really get any idea of what ur saying :( PS: Im 12
Unfortunately this was the first video to completely lose me. It was WAY too abstract for me to follow. I struggle to follow things that aren't accompanied by something demonstrating *why* I would be using the demonstrated method. As in, an actual program (even if super simple) with a tangible task. Simply seeing all those letters didn't make a lick of sense to me :-/ heading into the next tutorial and hoping that's where it will all make sense.
"Introduction" to Game Development
"Ep17"