1 00:00:04,500 --> 00:00:05,730 ‫Hello and welcome to this lecture. 2 00:00:05,730 --> 00:00:11,310 ‫We're going to be playing with AIM offsets that will allow our mesh to move its arms up and down. 3 00:00:11,310 --> 00:00:15,360 ‫As we aim up and down, let's dive in and see what that's all about. 4 00:00:16,170 --> 00:00:20,940 ‫So at the moment, if we aim up and down, you can see that our characters arms aren't actually doing 5 00:00:20,940 --> 00:00:26,370 ‫anything and the gun is not really looking like it should be pointing up and firing and hitting the 6 00:00:26,370 --> 00:00:28,440 ‫location that we're actually hitting. 7 00:00:28,710 --> 00:00:30,930 ‫So how do we go about changing this? 8 00:00:30,930 --> 00:00:33,450 ‫Well, it's a change to our animation blueprint. 9 00:00:33,450 --> 00:00:38,700 ‫So let's go ahead and open up the animation blueprint as a starting point and dock it to our main window. 10 00:00:39,120 --> 00:00:44,250 ‫And then I want to introduce you to a new type of animation asset that we haven't seen before. 11 00:00:44,250 --> 00:00:46,680 ‫We've seen blend spaces, we've seen animations. 12 00:00:46,680 --> 00:00:53,160 ‫The next thing that I want to show you is something called an animation offset and particularly an aim 13 00:00:53,160 --> 00:00:53,700 ‫offset. 14 00:00:53,700 --> 00:01:00,060 ‫So if we look for the keyword ayo in our animations, we're looking for these ones with a little blue 15 00:01:00,060 --> 00:01:02,130 ‫underline called aim offsets. 16 00:01:02,130 --> 00:01:03,090 ‫And there's a couple of them. 17 00:01:03,090 --> 00:01:09,180 ‫The one I'm interested in is AoE combat, which should be around here somewhere. 18 00:01:09,180 --> 00:01:11,730 ‫They would go a idle A0 combat. 19 00:01:11,970 --> 00:01:16,830 ‫If you go and select that, then you'll see that we've got something looking a lot like our blend space. 20 00:01:16,860 --> 00:01:22,530 ‫Except this time if you move the little green nubbin, what's going on is it's changing the direction 21 00:01:22,530 --> 00:01:25,680 ‫that our characters mesh is pointing. 22 00:01:25,680 --> 00:01:30,720 ‫So if we come over to the left, he points his gun to the left, we come over to the right, he points 23 00:01:30,720 --> 00:01:32,670 ‫his gun to the right. 24 00:01:32,670 --> 00:01:36,250 ‫And similarly with up and down, if you go pitch up, then he looks all the way up. 25 00:01:36,250 --> 00:01:39,240 ‫He pitched down, he looks all the way down and tries to shoot down. 26 00:01:39,510 --> 00:01:46,680 ‫Now the difference with this and other animations that we've seen is that this is known as an additive 27 00:01:46,680 --> 00:01:47,310 ‫animation. 28 00:01:47,310 --> 00:01:51,750 ‫If you go to the details pane, you can see that it's additive because it says additive settings and 29 00:01:51,750 --> 00:01:55,920 ‫there's this animation based pose that it's basing all of this off. 30 00:01:56,340 --> 00:02:01,560 ‫Basically what it means when it's additive is that this animation can be added on top of your other 31 00:02:01,560 --> 00:02:02,430 ‫animations. 32 00:02:02,430 --> 00:02:06,090 ‫So it's saying, I can do this aiming while you're running. 33 00:02:06,090 --> 00:02:13,320 ‫I can add the information about where my arms have moved relative to your run pose and add them on top. 34 00:02:13,500 --> 00:02:14,700 ‫So how does this look? 35 00:02:14,700 --> 00:02:22,200 ‫If we go to our animation blueprint, what we want to do is add this information after we've added all 36 00:02:22,200 --> 00:02:28,050 ‫this information about locomotion and probably not before death, because death should be the final 37 00:02:28,050 --> 00:02:28,530 ‫thing. 38 00:02:29,040 --> 00:02:31,140 ‫So we want to have the locomotion. 39 00:02:31,140 --> 00:02:32,970 ‫So we've got all our running animation in there. 40 00:02:32,970 --> 00:02:39,390 ‫We want to add on top of that the a little bit of information about where our arms should be moved so 41 00:02:39,390 --> 00:02:41,040 ‫that we're aiming correctly. 42 00:02:41,130 --> 00:02:45,060 ‫So to do this, we can right click and add in our aim offset. 43 00:02:45,060 --> 00:02:46,710 ‫We can do it from the asset browser as well. 44 00:02:46,710 --> 00:02:52,380 ‫I'm going to look for A0 and then as I said, we're looking for that combat version, which is a different 45 00:02:52,380 --> 00:02:53,580 ‫place in this browser. 46 00:02:53,580 --> 00:03:00,180 ‫Funnily enough, if I track that in, then what you get is something with an input pin which says What's 47 00:03:00,180 --> 00:03:01,140 ‫the base powered? 48 00:03:01,170 --> 00:03:07,050 ‫Notice that locomotion blend space didn't have an input pin because it's supplying you the whole animation, 49 00:03:07,140 --> 00:03:14,580 ‫whereas this aim offset because it's an additive animation, it requires something to add on top of. 50 00:03:14,580 --> 00:03:20,040 ‫So you need to give it a base pose which is going to come from our locomotion, and then we're going 51 00:03:20,040 --> 00:03:26,700 ‫to go and input that into our false pose of the blend, whether we are dead or not, because we're only 52 00:03:26,700 --> 00:03:28,260 ‫showing this if we're not dead. 53 00:03:29,000 --> 00:03:36,770 ‫And then I want to show you that if I were to change the pitch to one or maybe to 180, actually, and 54 00:03:36,770 --> 00:03:41,750 ‫go ahead and compile, then you can see that he's fully looking upwards. 55 00:03:41,900 --> 00:03:44,570 ‫Now, another tweak I want to do here is in the event graph. 56 00:03:44,570 --> 00:03:50,120 ‫At the moment, we've got a rather vexing situation where we can't tweak anything in the anim preview 57 00:03:50,120 --> 00:03:54,890 ‫because it's being overwritten with zeros by our event graph. 58 00:03:54,890 --> 00:04:01,850 ‫An easy way to fix this is to simply put a check in here for whether the pawn owner that we've got here 59 00:04:02,000 --> 00:04:04,370 ‫is valid, namely is it null? 60 00:04:04,820 --> 00:04:10,280 ‫So if we put an is valid here and the one with the question mark automatically gives us these execution 61 00:04:10,280 --> 00:04:18,140 ‫nodes and if we pass through our update animation execution node and only set things if that's valid, 62 00:04:18,170 --> 00:04:23,750 ‫then what's going to happen is that when you are not actually playing and there isn't a pawn there to 63 00:04:23,750 --> 00:04:26,960 ‫give us the information, it's going to allow us to set it in. 64 00:04:26,960 --> 00:04:28,470 ‫The Anim Preview Editor. 65 00:04:28,490 --> 00:04:36,620 ‫So now I can change the speed and you can see that he starts running with his aim offset set up high. 66 00:04:36,860 --> 00:04:41,090 ‫So let's set this so that our pitch is actually a variable here. 67 00:04:41,090 --> 00:04:47,120 ‫So I'm going to right click on pitch and promote the variable and bring that variable down here where 68 00:04:47,120 --> 00:04:50,510 ‫it's visible and change its name to pitch. 69 00:04:51,110 --> 00:04:54,530 ‫Or in fact, let's be more specific, this is the aim pitch like. 70 00:04:54,530 --> 00:05:00,290 ‫So now if we go ahead and compile, we set a default aim pitch by accident. 71 00:05:00,290 --> 00:05:03,380 ‫We want to set that down to zero by default. 72 00:05:03,560 --> 00:05:05,150 ‫I'm going to go ahead and compile that. 73 00:05:05,150 --> 00:05:11,270 ‫And now if we go ahead and change the speed and then change the aim pitch. 74 00:05:12,110 --> 00:05:17,090 ‫You can see we can aim up and we can aim down, which is exactly what we want. 75 00:05:17,120 --> 00:05:20,180 ‫Now, the problem here is it's not being set in our game just yet. 76 00:05:20,180 --> 00:05:26,930 ‫If we go up and down, none of that is coming from information from our control rotation and our aiming. 77 00:05:27,020 --> 00:05:31,040 ‫So we need to go back to our event graph and get some of that information in here. 78 00:05:31,070 --> 00:05:36,050 ‫Now, I'm just going to space things out a little bit here because this is getting rather long. 79 00:05:36,050 --> 00:05:42,680 ‫And what I want to do is off this valid pin is I want to put a sequence node which is going to let me 80 00:05:42,770 --> 00:05:47,720 ‫spread things out a little bit down the in the vertical direction as well. 81 00:05:47,720 --> 00:05:53,030 ‫So the sequence node, first of all, is going to go off to setting the speed and angle over here. 82 00:05:53,030 --> 00:05:57,290 ‫Then I think we can move this stuff to do with casting to the shooter character. 83 00:05:57,380 --> 00:06:04,610 ‫I think we can bring this down further vertically, hooking up that sequence pin and the object pin 84 00:06:04,610 --> 00:06:09,860 ‫to our try get pawn owner node, then we can add another pin into the sequence. 85 00:06:09,860 --> 00:06:13,820 ‫And this time I want to get two pieces of information from our pawn owner. 86 00:06:13,940 --> 00:06:17,330 ‫The first one is going to be our control rotation. 87 00:06:17,330 --> 00:06:20,060 ‫So let's do a get control rotation. 88 00:06:20,360 --> 00:06:26,360 ‫But this isn't going to be enough because our control rotation, if we split the pin, you can see we've 89 00:06:26,360 --> 00:06:29,570 ‫got a pitch in here and we could try setting that pitch. 90 00:06:29,570 --> 00:06:30,950 ‫Let's let's give that a go. 91 00:06:30,980 --> 00:06:38,570 ‫So if I do a set pitch and connect up the execution node to the execution node from our sequence, adding 92 00:06:38,570 --> 00:06:44,960 ‫in a bit of a redirect to there, what's going to happen if we compile, save, hit play and then aim 93 00:06:44,960 --> 00:06:46,320 ‫up works fine. 94 00:06:46,340 --> 00:06:48,800 ‫Aim down does not turn around. 95 00:06:48,800 --> 00:06:52,310 ‫Then things start to look even more weird. 96 00:06:52,400 --> 00:06:59,330 ‫Now what's going on there is that this control rotation is entirely global and so doesn't take into 97 00:06:59,330 --> 00:07:02,870 ‫account the direction that our player is already facing. 98 00:07:02,930 --> 00:07:10,910 ‫So to take that into account, we need to go to the pawn again and get the actor rotation. 99 00:07:10,910 --> 00:07:18,560 ‫And then what we want to find is the rotation between the actor's rotation to the control rotation. 100 00:07:18,560 --> 00:07:22,640 ‫And the way we do this is I'm just going to disconnect the AM pitch. 101 00:07:22,940 --> 00:07:28,730 ‫Break that link and right click and recombine the struct pins is I want to do a delta between those 102 00:07:28,730 --> 00:07:33,470 ‫two so I can take off of the control rotation and look for Delta. 103 00:07:34,240 --> 00:07:41,280 ‫And Delta is basically a fancy way of saying subtraction between rotators. 104 00:07:41,290 --> 00:07:48,820 ‫So what we want to do is take our control rotation and subtract the base rotation, which is going to 105 00:07:48,820 --> 00:07:50,830 ‫be our actor rotation. 106 00:07:50,830 --> 00:07:55,930 ‫So that's B so it's going to be A minus B if you hover over, that's what the Delta rotator does. 107 00:07:56,050 --> 00:08:01,660 ‫And we basically want to be saying, Yeah, I want the control rotation, but take away all that information 108 00:08:01,660 --> 00:08:03,610 ‫about our active rotation. 109 00:08:03,610 --> 00:08:10,270 ‫So I can just know whether we're aiming up and down relative to the direction that our character is 110 00:08:10,270 --> 00:08:10,960 ‫facing. 111 00:08:11,110 --> 00:08:17,830 ‫And then if I split out the return value pin from that and use the pitch from there, we're going to 112 00:08:17,830 --> 00:08:20,170 ‫see that everything works as expected. 113 00:08:20,170 --> 00:08:26,950 ‫When I look up my naming up, when I look down, I'm aiming down and doesn't matter which way I'm facing 114 00:08:26,950 --> 00:08:29,440 ‫in the world, that's always going to be the case. 115 00:08:29,440 --> 00:08:33,220 ‫So that's almost it for our aim rotation. 116 00:08:33,220 --> 00:08:38,350 ‫The only problem is that at the moment our eye is incapable of aiming like this. 117 00:08:38,350 --> 00:08:46,660 ‫So if I go and put a shooter character up on the stairs over here and then we go over to try and hound 118 00:08:46,660 --> 00:08:49,420 ‫him down, try and get him to come over to us. 119 00:08:49,420 --> 00:08:50,500 ‫Here he comes. 120 00:08:50,500 --> 00:08:53,350 ‫You can see that he's just shooting off into the wall. 121 00:08:53,350 --> 00:08:56,200 ‫He's not trying to aim at all, which is a bit sad. 122 00:08:56,200 --> 00:08:57,670 ‫So what's going on there? 123 00:08:57,670 --> 00:09:04,120 ‫If we go to our eye and our behavior tree, you can see that we're setting a default focus to a location. 124 00:09:04,120 --> 00:09:10,210 ‫And by default, if you set a focus to a location, then Unreal is not going to update your control 125 00:09:10,210 --> 00:09:13,540 ‫rotation in the same way it's not going to do the pitch. 126 00:09:13,720 --> 00:09:15,100 ‫So that's a bit sad. 127 00:09:15,100 --> 00:09:21,970 ‫Okay, so what we need to do is go to a blackboard and change this player location to just be a reference 128 00:09:21,970 --> 00:09:23,680 ‫to the player instead. 129 00:09:24,060 --> 00:09:27,790 ‫Then we need to change this vector over to be an object. 130 00:09:27,790 --> 00:09:33,430 ‫So now what we've got is a blackboard key for the player, which is an object, and we can change the 131 00:09:33,430 --> 00:09:38,860 ‫base class to b actor if we want to, although it's not particularly important. 132 00:09:38,860 --> 00:09:44,620 ‫And then what that means is over in the behavior tree, we can switch things up so that we are moving 133 00:09:44,620 --> 00:09:49,570 ‫to instead of moving to our player location, we're moving to the player actor. 134 00:09:49,570 --> 00:09:55,330 ‫We can set the focus to be the player actor and update the player. 135 00:09:55,330 --> 00:10:00,400 ‫Location of scene now needs to be pointing to a player actor as well. 136 00:10:00,400 --> 00:10:05,860 ‫Now, this isn't going to work just yet because our update player location of scene is currently trying 137 00:10:05,860 --> 00:10:08,260 ‫to set a location into this key. 138 00:10:08,260 --> 00:10:11,050 ‫So a little mini challenge for you, see if you can update it. 139 00:10:11,050 --> 00:10:18,810 ‫So instead of setting the location in that behavior tree service, we're setting the actual actor pause 140 00:10:18,820 --> 00:10:19,720 ‫video and have a go. 141 00:10:19,750 --> 00:10:20,650 ‫Okay, welcome back. 142 00:10:20,650 --> 00:10:25,810 ‫So we're going to go over in to Visual Studio code and look for our service particularly. 143 00:10:25,810 --> 00:10:29,650 ‫It's the service underscore player location if seen. 144 00:10:29,800 --> 00:10:35,830 ‫And we're going to change this to instead of set value as vector, it's going to be set value as object, 145 00:10:36,280 --> 00:10:37,090 ‫simple as that. 146 00:10:37,090 --> 00:10:42,190 ‫We had the choices of types in the blackboard, and that's what we're going to tell it here. 147 00:10:42,220 --> 00:10:46,360 ‫Now, obviously, it's going to complain that what we're trying to set is a vector rather than an object. 148 00:10:46,360 --> 00:10:51,280 ‫So we're going to just remove the get actor location and pass in the player pawn. 149 00:10:51,280 --> 00:10:56,860 ‫Instead, clearing the value is the same as it was before, so we can just go back into the editor, 150 00:10:56,890 --> 00:11:03,340 ‫hit, compile, and see if this new set up is working with aiming for the I Kate let's dive in hit play. 151 00:11:03,370 --> 00:11:05,800 ‫Go and find out I up on the stairs. 152 00:11:06,590 --> 00:11:13,250 ‫Get them to try and come and look down as come on I and one more thing that I've forgotten from the 153 00:11:13,250 --> 00:11:19,820 ‫behaviour tree to update is the cansee player at the moment is has gone on reset the blackboard key 154 00:11:19,820 --> 00:11:26,600 ‫to self actor we want to that to be player basically is the player set let's go and make that change 155 00:11:26,600 --> 00:11:31,700 ‫because at the moment the I wasn't coming to chase us now it's chasing us and in fact if you jump, 156 00:11:31,730 --> 00:11:36,050 ‫you can just about see that the aim rotation of this guy is changing. 157 00:11:36,050 --> 00:11:40,550 ‫Let's go over to the stairs and see whether he can shoot down from the stairs at us. 158 00:11:41,030 --> 00:11:41,690 ‫Excellent. 159 00:11:41,690 --> 00:11:46,130 ‫He's changed his rotation and indeed he is shooting right at us. 160 00:11:46,130 --> 00:11:47,300 ‫Both of them are where? 161 00:11:47,300 --> 00:11:49,250 ‫So I'm losing health and will soon die. 162 00:11:50,600 --> 00:11:57,080 ‫Okay, that's it for this lecture we have added in an aim offset and we have updated our eye so that 163 00:11:57,080 --> 00:11:59,150 ‫it can use that to aim as well. 164 00:11:59,180 --> 00:12:03,410 ‫The next lecture we're going to be doing something about this funny running while in the air. 165 00:12:03,410 --> 00:12:04,370 ‫I will see you there.