1 00:00:00,000 --> 00:00:06,240 Hey, welcome back, My favorite game developers in this video, 2 00:00:06,235 --> 00:00:10,125 our gun is no longer a static object. 3 00:00:10,120 --> 00:00:11,740 If you look closely, 4 00:00:11,740 --> 00:00:13,810 you can see that when we move down, 5 00:00:13,810 --> 00:00:15,250 the gun moves down. 6 00:00:15,250 --> 00:00:16,600 When we look up, 7 00:00:16,600 --> 00:00:17,970 the gun locks up. 8 00:00:17,965 --> 00:00:21,225 Obviously, there are still a couple of things that need to be 9 00:00:21,220 --> 00:00:25,740 fixed because holding the gun like that I feel is pretty uncomfortable, 10 00:00:25,735 --> 00:00:27,505 but no worries about that. 11 00:00:27,505 --> 00:00:31,735 This is the first step in naming our gun properly. 12 00:00:31,735 --> 00:00:35,635 So let's not waste any more time and let's get started. 13 00:00:35,635 --> 00:00:37,335 There's a lot of math in this. 14 00:00:37,330 --> 00:00:40,070 So put your thinking caps on. 15 00:00:41,770 --> 00:00:46,810 Now that we are moving and we're bumping into things, 16 00:00:46,805 --> 00:00:50,135 it's time to start aiming our weapon. 17 00:00:50,135 --> 00:00:55,495 To do that, we want to rotate the weapon around a certain position. 18 00:00:55,490 --> 00:01:01,460 We don't want to actually be rotating the exact weapon because if we look in here, 19 00:01:01,460 --> 00:01:03,400 if we go to the scene, 20 00:01:03,395 --> 00:01:04,475 you can see right now, 21 00:01:04,475 --> 00:01:06,995 if we try to rotate the gun as it is, 22 00:01:06,995 --> 00:01:08,675 it doesn't look as good. 23 00:01:08,675 --> 00:01:13,415 We need a point from which the gun will be rotating. 24 00:01:13,415 --> 00:01:17,915 So what we'll do is we're going to right-click on the dome player. 25 00:01:17,915 --> 00:01:20,675 We're going to create an empty game object. 26 00:01:20,675 --> 00:01:26,305 We are going to call it the weapons arm. 27 00:01:26,300 --> 00:01:29,720 And we're going to move it to a certain point. 28 00:01:29,720 --> 00:01:34,940 And this is the point where the gun or from which the gun will be rotating. 29 00:01:34,940 --> 00:01:40,570 So I'm going to put it around almost the hand or the arm of the player. 30 00:01:40,565 --> 00:01:42,575 And I am going to make the shotgun, 31 00:01:42,575 --> 00:01:45,575 a child of that weapons are. 32 00:01:45,575 --> 00:01:49,495 So now when we rotate the weapons arm, 33 00:01:49,490 --> 00:01:55,400 you'll notice that the shotgun stays in its place almost around the arm right here, 34 00:01:55,400 --> 00:02:02,720 and it looks much more natural as we rotate the shotgun or the weapons are. 35 00:02:02,720 --> 00:02:05,530 So now it's time for a bit of cold. 36 00:02:05,525 --> 00:02:07,105 But before we do that, 37 00:02:07,100 --> 00:02:10,330 how are we actually going to be rotating this arm? 38 00:02:10,325 --> 00:02:14,065 It's going to be dependent on where our mouth is. 39 00:02:14,060 --> 00:02:16,130 So let's say we are up here. 40 00:02:16,130 --> 00:02:19,190 We want the shot gun to point towards the mouse. 41 00:02:19,190 --> 00:02:21,770 How are we going to calculate that? 42 00:02:21,770 --> 00:02:29,210 Well, we will need a couple of points and let me explain it using math, yay math. 43 00:02:29,210 --> 00:02:31,130 So let's get started. 44 00:02:31,130 --> 00:02:34,900 First thing first we need the player position on the screen. 45 00:02:34,895 --> 00:02:37,345 Well, I use the term player position, 46 00:02:37,340 --> 00:02:42,500 but it's actually the point on which we are rotating the shotgun around. 47 00:02:42,500 --> 00:02:44,600 But for now, let's just keep it simple. 48 00:02:44,600 --> 00:02:46,690 Call this the player position, 49 00:02:46,685 --> 00:02:49,585 and we have the mouse position on the screen. 50 00:02:49,580 --> 00:02:55,360 So what we want is we want to get the vector on these two points. 51 00:02:55,355 --> 00:02:59,345 This is the direction which are gone will be pointing. 52 00:02:59,345 --> 00:03:06,055 But how are we actually going to calculate the angle we want the gun to be pointing in? 53 00:03:06,050 --> 00:03:11,390 Well, we know the exposition and we know the y position. 54 00:03:11,390 --> 00:03:13,580 Well, I meant X and Y. 55 00:03:13,580 --> 00:03:18,830 So what we can do is we can use something called the arc tangent. 56 00:03:18,830 --> 00:03:22,670 And this is something available for us in math. 57 00:03:22,670 --> 00:03:26,170 F of unit is library. 58 00:03:26,165 --> 00:03:29,555 So we can use that to calculate the arctan. 59 00:03:29,555 --> 00:03:33,595 And if you don't know what arctan or you don't even know what Dan is 60 00:03:33,590 --> 00:03:38,210 tangent I believe it's called it's the front side, 61 00:03:38,210 --> 00:03:41,960 which is the y divided by V x. 62 00:03:41,960 --> 00:03:43,370 And when we do that, 63 00:03:43,370 --> 00:03:45,050 we get a certain number, 64 00:03:45,050 --> 00:03:46,450 which is the tangent. 65 00:03:46,445 --> 00:03:48,355 So to get the angle, 66 00:03:48,350 --> 00:03:50,930 we use something called the arc tangent, 67 00:03:50,930 --> 00:03:52,960 which is kind of a reverse. 68 00:03:52,955 --> 00:03:57,035 But all you need to know is that we get the difference in the height, 69 00:03:57,035 --> 00:04:00,475 we get the difference in the distance. 70 00:04:00,470 --> 00:04:05,950 And using that, we calculate the angle in which argon should be pointing out. 71 00:04:05,945 --> 00:04:08,825 This is basic elementary math. 72 00:04:08,825 --> 00:04:10,975 I'm not sure if you're familiar with that. 73 00:04:10,970 --> 00:04:13,960 If you want to delve deeper into it, be my guest, 74 00:04:13,955 --> 00:04:17,275 I believe this will be enough explanation. 75 00:04:17,270 --> 00:04:22,030 So let's translate these mathematical equations into mathematical codes. 76 00:04:22,025 --> 00:04:26,695 So I'm going to go back and our script in here in the player controller. 77 00:04:26,690 --> 00:04:32,540 And the first thing we need is the two reference for the camera and for the weapons are. 78 00:04:32,540 --> 00:04:36,550 So I'm going to start off by creating a serialized field, 79 00:04:36,545 --> 00:04:38,755 which will be a transform. 80 00:04:38,750 --> 00:04:44,540 And it's going to represent the weapons are great. 81 00:04:44,540 --> 00:04:49,130 The second variable we're going to create as a private camera, 82 00:04:49,130 --> 00:04:51,910 and it's going to be the main camera. 83 00:04:51,905 --> 00:04:55,735 And the cool thing about this is that we can immediately go into 84 00:04:55,730 --> 00:05:00,670 Stuart and say that the main camera is equal to the camera. 85 00:05:00,665 --> 00:05:02,495 Dot main. 86 00:05:02,495 --> 00:05:04,735 And using this camera, that main, 87 00:05:04,730 --> 00:05:09,610 we immediately can get a reference to the main camera which we have. 88 00:05:09,605 --> 00:05:11,155 And here, great. 89 00:05:11,150 --> 00:05:15,550 Now we need to know where our mouth is in the world. 90 00:05:15,545 --> 00:05:17,995 So we are going to scroll down and here, 91 00:05:17,990 --> 00:05:21,970 and I'm just going to remove these comments because we no longer need them. 92 00:05:21,965 --> 00:05:23,875 If you feel you need them, 93 00:05:23,870 --> 00:05:29,240 keep them as a reminder for later on how we changed and moved through our code. 94 00:05:29,240 --> 00:05:32,780 So now I'm going to get the position of the mouse. 95 00:05:32,780 --> 00:05:36,100 I'm going to use a vector three. 96 00:05:36,095 --> 00:05:41,545 And it's going to be called the mouse position. 97 00:05:41,540 --> 00:05:48,080 And it's going to be equal to the input dot mouse position. 98 00:05:48,080 --> 00:05:52,340 And you can see right now that immediately the Visual Studio Community 99 00:05:52,340 --> 00:05:56,810 gives us the current mouse position in pixel coordinates. 100 00:05:56,810 --> 00:05:58,670 So great, that's what we need. 101 00:05:58,670 --> 00:06:00,970 And obviously, I already know this stuff. 102 00:06:00,965 --> 00:06:03,215 If you want to research this, 103 00:06:03,215 --> 00:06:05,915 you would have needed to go into Google, 104 00:06:05,915 --> 00:06:07,595 how to go get most position. 105 00:06:07,595 --> 00:06:10,915 You have gotten the documentations for unity. 106 00:06:10,910 --> 00:06:14,410 You would have found this input dot mouse position. 107 00:06:14,405 --> 00:06:15,635 You would have used it. 108 00:06:15,635 --> 00:06:17,245 This is just a shortcut. 109 00:06:17,240 --> 00:06:20,420 Let's continue on. Next thing we need is the screen point. 110 00:06:20,420 --> 00:06:27,830 So screen point, and it's going to be equal to the main camera, 111 00:06:27,830 --> 00:06:33,560 the world camera, world to screen point. 112 00:06:33,560 --> 00:06:36,350 And you can see the definition and here is 113 00:06:36,350 --> 00:06:40,820 the transform position from world space and to screen space. 114 00:06:40,820 --> 00:06:43,190 There we go. This is what we need. 115 00:06:43,190 --> 00:06:48,560 Transform local scale, I mean local position. 116 00:06:48,560 --> 00:06:52,490 And this will give us the local position of the transform, 117 00:06:52,490 --> 00:06:55,130 which is the player right now. 118 00:06:55,130 --> 00:06:58,750 And now it's time to calculate the angle. 119 00:06:58,745 --> 00:07:01,205 Let's first of all, save all of that. 120 00:07:01,205 --> 00:07:06,315 Let's go ahead and assign the arm for the player. 121 00:07:06,315 --> 00:07:09,145 So I'm going to drag the weapons arm right now. 122 00:07:09,145 --> 00:07:10,495 We're going to save that. 123 00:07:10,495 --> 00:07:14,925 And now the next step is to actually calculate the angle. 124 00:07:14,920 --> 00:07:17,520 So I'm going to first of all, 125 00:07:17,515 --> 00:07:22,485 show you this again so you can go back and look at it if you need to. 126 00:07:22,480 --> 00:07:25,440 And then I'm going to issue you a challenge. 127 00:07:25,435 --> 00:07:29,415 And your challenge is going to be to calculate the angle. 128 00:07:29,410 --> 00:07:33,030 So first thing you do is you need to subtract 129 00:07:33,025 --> 00:07:38,635 the mouse x position from the screen point position of the x. 130 00:07:38,635 --> 00:07:42,715 Obviously, you will need to do the same for the y. 131 00:07:42,715 --> 00:07:44,535 And then you'll need to calculate 132 00:07:44,530 --> 00:07:51,020 the math F dot arctangent to find that in the Unity documentation. 133 00:07:51,020 --> 00:07:53,650 Go ahead, pause the video right now. 134 00:07:53,645 --> 00:07:54,905 Go do your best. 135 00:07:54,905 --> 00:07:55,655 Try it. 136 00:07:55,655 --> 00:07:58,955 You won't lose anything by doing your best. 137 00:07:58,955 --> 00:08:03,385 Pause the video right now and go do the challenge. 138 00:08:03,380 --> 00:08:05,810 Hey, welcome back. 139 00:08:05,810 --> 00:08:07,250 So as you can see, 140 00:08:07,250 --> 00:08:09,110 I've just looked up math, 141 00:08:09,110 --> 00:08:11,600 arc tangent in Unity. 142 00:08:11,600 --> 00:08:13,660 Now I am right here. 143 00:08:13,655 --> 00:08:17,695 What do I do? Well, I need to see how this works. 144 00:08:17,690 --> 00:08:19,890 What does do? It returns a float. 145 00:08:19,894 --> 00:08:23,004 This is our how I use matlab.org Tange. 146 00:08:23,000 --> 00:08:24,200 Okay, great. 147 00:08:24,200 --> 00:08:25,960 Then let's go back in here. 148 00:08:25,955 --> 00:08:29,605 So first thing we need to do is we need to calculate the difference. 149 00:08:29,600 --> 00:08:33,760 I'm going to put both of these into a vector two. 150 00:08:33,755 --> 00:08:36,415 So I'm going to use a vector to, 151 00:08:36,410 --> 00:08:39,330 I'll call this the offset. 152 00:08:39,334 --> 00:08:42,484 So it's the offset between the two points. 153 00:08:42,485 --> 00:08:47,825 It will be equal to a new vector two. 154 00:08:47,825 --> 00:08:55,145 And in here I'm going to first of all get the mouse position dot x and subtract from it, 155 00:08:55,145 --> 00:08:58,495 the screen point directs. 156 00:08:58,490 --> 00:09:03,060 And I'm going to do the same on the why. 157 00:09:07,750 --> 00:09:13,870 Now I'm going to create a float because as we saw this method, 158 00:09:13,865 --> 00:09:17,675 the method dot arctan returns a float, 159 00:09:17,675 --> 00:09:25,225 is going to be equal to math F dot arc tan or no, Eta. 160 00:09:25,220 --> 00:09:27,980 It's called a tan two. 161 00:09:27,980 --> 00:09:36,600 And I'm going to use the offset dot y divided by the offset DRX. 162 00:09:36,730 --> 00:09:39,620 Great, so I'm going to save that. 163 00:09:39,620 --> 00:09:46,780 But whenever we want to assign the actual rotation to the weapons are, 164 00:09:46,775 --> 00:09:50,045 we cannot simply do it using a float. 165 00:09:50,045 --> 00:09:54,745 What we need to do is we need to use an extra method, 166 00:09:54,740 --> 00:10:00,880 which is the method that rad two degrees. 167 00:10:00,875 --> 00:10:04,745 And you can see this converts radians to degrees constant. 168 00:10:04,745 --> 00:10:07,405 So we will need to do that. 169 00:10:07,400 --> 00:10:11,720 And the final thing we need to do is we will need to access the weapons on 170 00:10:11,720 --> 00:10:17,170 dot rotation and now get ready for a bit of a scary world. 171 00:10:17,165 --> 00:10:19,555 We are going to use quaternions. 172 00:10:19,550 --> 00:10:23,810 So quaternion dot Bueller. 173 00:10:23,809 --> 00:10:30,169 And we're going to set it as 00 on the x-axis. 174 00:10:30,170 --> 00:10:32,870 We don't rotate on the y-axis, we don't rotate. 175 00:10:32,870 --> 00:10:36,830 We only rotate around the z-axis using the angle. 176 00:10:36,830 --> 00:10:39,320 Now, before you run away, 177 00:10:39,320 --> 00:10:42,580 what is Turnitin dot Hulu? 178 00:10:42,575 --> 00:10:45,155 If you look on the earlier right here, 179 00:10:45,155 --> 00:10:50,285 you can see that it returns a rotation that rotate Z degrees around z axis, 180 00:10:50,285 --> 00:10:51,715 x around x axis, 181 00:10:51,710 --> 00:10:53,060 and so on and so forth. 182 00:10:53,060 --> 00:10:55,400 So quaternion dot. 183 00:10:55,400 --> 00:10:57,020 If you are interested, 184 00:10:57,020 --> 00:10:58,930 you can delve deep into this. 185 00:10:58,925 --> 00:11:03,055 Me personally, I've been rotating objects in Unity for 186 00:11:03,050 --> 00:11:07,460 several years and I've never quite understood what they 187 00:11:07,460 --> 00:11:11,630 mean by quaternion is just a way to convert 188 00:11:11,630 --> 00:11:16,340 from the XYZ into an actual rotation and space. 189 00:11:16,340 --> 00:11:19,550 So feel free to delve deep, 190 00:11:19,550 --> 00:11:22,450 go look it up, make sure you understand everything. 191 00:11:22,445 --> 00:11:25,285 If not, if you're not bothered by not fully 192 00:11:25,280 --> 00:11:28,910 understanding what is happening with quaternion u dot. 193 00:11:28,910 --> 00:11:34,640 Trust me, you can go through your game development journey without worrying about it. 194 00:11:34,640 --> 00:11:38,150 So this is simply a way to convert x, 195 00:11:38,150 --> 00:11:41,450 y, and z into an angle into a rotation. 196 00:11:41,450 --> 00:11:42,580 We'll save that. 197 00:11:42,575 --> 00:11:44,555 We'll go back into Unity. 198 00:11:44,555 --> 00:11:47,915 And we are going to run the game. 199 00:11:47,915 --> 00:11:51,875 And let's see what is happening with the gun right now, 200 00:11:51,875 --> 00:11:53,995 we move up, the gun moves up. 201 00:11:53,990 --> 00:11:56,210 We move down. The gun moves down. 202 00:11:56,210 --> 00:11:58,430 If we go to the left, yep. 203 00:11:58,430 --> 00:12:02,480 Our gun looks a bit weird when we look in the other direction, 204 00:12:02,480 --> 00:12:06,490 but when it comes to the proper direction, there you go. 205 00:12:06,485 --> 00:12:09,445 We move and even adjusts as we walk. 206 00:12:09,440 --> 00:12:11,830 So you can see when we move up, 207 00:12:11,825 --> 00:12:13,115 the gun moves down. 208 00:12:13,115 --> 00:12:18,425 Always looking at exactly where our mouse position is. 209 00:12:18,425 --> 00:12:22,315 So great now we have a gun that is actually firing, 210 00:12:22,310 --> 00:12:25,910 which is amazing in my opinion, not actually firing, 211 00:12:25,910 --> 00:12:30,730 which will be firing in the right direction later on as we move. 212 00:12:30,725 --> 00:12:33,445 But obviously there is something wrong when 213 00:12:33,440 --> 00:12:36,280 we try to move the mouse in the other direction, 214 00:12:36,275 --> 00:12:38,025 it does move properly. 215 00:12:38,029 --> 00:12:43,069 That's what we are going to be fixing in the next video while learning 216 00:12:43,069 --> 00:12:48,699 something very nice encoding which is called the if statements and if conditions. 217 00:12:48,695 --> 00:12:50,845 So I'll see you there. 218 00:12:50,840 --> 00:12:52,160 But before we go, 219 00:12:52,160 --> 00:12:55,640 always make sure to stage all your files. 220 00:12:55,640 --> 00:12:57,250 Mega commits. 221 00:12:57,245 --> 00:13:03,125 I'm going to call this made my gun point in 222 00:13:03,125 --> 00:13:09,575 the right direction or not envy right angle. 223 00:13:09,575 --> 00:13:10,945 Because in the next video, 224 00:13:10,940 --> 00:13:13,250 we'll make it point in the right direction, 225 00:13:13,250 --> 00:13:16,520 will make the whole player point and the right direction. 226 00:13:16,520 --> 00:13:19,290 So, see you then.