1 00:00:04,530 --> 00:00:05,310 ‫Hello and welcome. 2 00:00:05,310 --> 00:00:10,830 ‫In this lecture, we are going to introduce you to a new part of the animation blueprint called a state 3 00:00:10,830 --> 00:00:11,370 ‫machine. 4 00:00:11,370 --> 00:00:12,780 ‫Very useful part of it. 5 00:00:12,780 --> 00:00:18,990 ‫And what it will allow us to do is if we hit a Boolean switch here, it's going to allow us to transition 6 00:00:18,990 --> 00:00:22,740 ‫into a jumping state and then back down to grounded. 7 00:00:22,740 --> 00:00:27,090 ‫Let's see how all of this works and how we can create this for ourselves. 8 00:00:28,050 --> 00:00:28,290 ‫Okay. 9 00:00:28,290 --> 00:00:33,480 ‫So we've got this really weird behavior when we jump, which just means that we end up running in midair, 10 00:00:33,480 --> 00:00:36,270 ‫which is obviously not a very good look. 11 00:00:36,480 --> 00:00:41,790 ‫Now, to fix this, we're going to need to learn about a whole new animation concept called an animation 12 00:00:41,790 --> 00:00:42,570 ‫state machine. 13 00:00:42,570 --> 00:00:44,640 ‫So this belongs in the animation blueprint. 14 00:00:44,640 --> 00:00:48,300 ‫So go ahead and get that fired up if you haven't got it fired up already. 15 00:00:48,540 --> 00:00:55,080 ‫And over in the anim graph, so far everything we've done in the graph has been through these nodes 16 00:00:55,080 --> 00:00:55,740 ‫here. 17 00:00:55,860 --> 00:01:01,020 ‫Now, what I want to show you is how we can add something new, something called a state machine. 18 00:01:01,110 --> 00:01:07,110 ‫We're going to right click and this is in the anim graph and we're going to look for state machine. 19 00:01:07,110 --> 00:01:11,620 ‫And you can see that this ad, new state machine is one option here. 20 00:01:11,640 --> 00:01:15,380 ‫Now, I want to show you that there's another way of doing this as well. 21 00:01:15,390 --> 00:01:17,910 ‫If you right click all the way back. 22 00:01:17,910 --> 00:01:24,720 ‫So if we right click in the anim graph and search for new state machine, then we've got this option. 23 00:01:24,720 --> 00:01:31,470 ‫Here we click, it creates a new node and you can see that node has a single animation PO's output pin 24 00:01:31,740 --> 00:01:37,950 ‫and over in the left hand pane in the My Blueprint, it's created this new state machine underneath 25 00:01:37,950 --> 00:01:39,360 ‫our anim graph. 26 00:01:39,360 --> 00:01:45,480 ‫So if you either double click on the new state machine or click it over in the anim graph, you see 27 00:01:45,480 --> 00:01:47,670 ‫it takes you to this new window. 28 00:01:47,670 --> 00:01:48,900 ‫So it's yet another thing. 29 00:01:48,900 --> 00:01:53,850 ‫We've got our anim graph, our event graph, and now we've got this state machine graph. 30 00:01:54,510 --> 00:01:55,980 ‫We can actually rename that. 31 00:01:55,980 --> 00:02:01,770 ‫So we can give our state machine a better name by clicking it in the My Blueprint and hitting two. 32 00:02:01,770 --> 00:02:05,730 ‫And we can call it locomotion because this is going to be all about locomotion. 33 00:02:05,730 --> 00:02:07,710 ‫And then what does a state machine do? 34 00:02:07,710 --> 00:02:11,880 ‫Well, a state machine is at its simplest, it's a set of if you right click. 35 00:02:11,880 --> 00:02:14,190 ‫In fact, you can see there's a couple of options here. 36 00:02:14,190 --> 00:02:15,690 ‫There's a comment, there's a conduit. 37 00:02:15,690 --> 00:02:19,950 ‫But the most important thing is it states it is a machine full of states. 38 00:02:19,950 --> 00:02:22,860 ‫And I can add a couple of states in here to give you an idea. 39 00:02:22,860 --> 00:02:25,050 ‫So we've got state, state one, state two. 40 00:02:25,350 --> 00:02:29,670 ‫And then if you drag off of this border, it creates something called a transition. 41 00:02:29,670 --> 00:02:32,550 ‫So you can create a transition between states. 42 00:02:32,820 --> 00:02:38,730 ‫And we've got this entry pin which basically is telling us where which state should be started. 43 00:02:39,120 --> 00:02:39,440 ‫Okay. 44 00:02:39,450 --> 00:02:40,830 ‫So let's take a little step back. 45 00:02:40,830 --> 00:02:42,300 ‫What does this all mean? 46 00:02:42,960 --> 00:02:49,140 ‫Well, in each given state, if you double click on it, you can see that there is an output pin and 47 00:02:49,140 --> 00:02:55,350 ‫that output pin can be used in the same way as our anim graph can be used to build up an animation pose. 48 00:02:55,350 --> 00:03:00,150 ‫So in its simplest form, we might just decide to stick an animation in here. 49 00:03:00,150 --> 00:03:03,540 ‫So select any old animation playability, for example. 50 00:03:03,540 --> 00:03:09,540 ‫And that's the animation that's going to be played when the state machine is in a given state. 51 00:03:09,930 --> 00:03:11,820 ‫Now, how do we get into a given state? 52 00:03:11,820 --> 00:03:15,060 ‫Well, we might get into a given state because our entry node points to it. 53 00:03:15,060 --> 00:03:16,710 ‫And so that's the default state. 54 00:03:16,710 --> 00:03:18,060 ‫That's where we start off. 55 00:03:18,270 --> 00:03:21,990 ‫But then we might get to a state via a series of transitions as well. 56 00:03:22,350 --> 00:03:27,150 ‫So the transitions each have properties, you can double click on a transition and you can see that 57 00:03:27,150 --> 00:03:27,390 ‫again. 58 00:03:27,390 --> 00:03:32,340 ‫We get this node editor pop up and we can have some sort of boolean property. 59 00:03:32,340 --> 00:03:39,030 ‫So I don't know we could have some thing like is dead, we can get is dead we can pipe that into here 60 00:03:39,030 --> 00:03:41,820 ‫and now every time is dead is true. 61 00:03:41,850 --> 00:03:48,120 ‫We're going to make the transition if we're in this original state, if we are dead, then we'll make 62 00:03:48,120 --> 00:03:52,200 ‫the transition into state one and we'll start playing the animation in State one. 63 00:03:52,200 --> 00:03:57,870 ‫And then if the transitions from State one are true, for whatever reason, we might make the transition 64 00:03:57,870 --> 00:03:59,070 ‫over to State two. 65 00:03:59,610 --> 00:04:05,880 ‫Okay, so this is all very well and good in theory, but how does this help us in practice with running? 66 00:04:06,300 --> 00:04:11,130 ‫Well, for example, we might want a state that says grounded. 67 00:04:11,760 --> 00:04:16,440 ‫And in the grounded state, we're going to play our ground locomotion. 68 00:04:16,440 --> 00:04:21,520 ‫So if we go back up to our anim graph, what is our grounded locomotion? 69 00:04:21,540 --> 00:04:23,940 ‫It is basically everything here. 70 00:04:23,940 --> 00:04:30,720 ‫Before the we add our idle combat offset, there's this locomotion blend space is our grounded offset. 71 00:04:30,720 --> 00:04:39,300 ‫So I'm going to cut the nodes here, go and hook up my locomotion state machine to pass in to our aim 72 00:04:39,300 --> 00:04:40,110 ‫offset. 73 00:04:40,230 --> 00:04:45,480 ‫Then I'm going to go into the locomotion state machine, go into the grounded state and paste in those 74 00:04:45,480 --> 00:04:48,600 ‫nodes here and connect them up to the output pin. 75 00:04:48,750 --> 00:04:52,620 ‫So let's follow what's going on here at the anim graph level. 76 00:04:53,130 --> 00:04:58,320 ‫First of all, we are running the animation locomotion state machine. 77 00:04:58,500 --> 00:05:04,380 ‫And because I haven't hooked this up, but because the entry pin points to the grounded state, we're 78 00:05:04,380 --> 00:05:08,520 ‫automatically in the grounded state, it's going to go into there, figure out, okay, we've got a 79 00:05:08,520 --> 00:05:12,390 ‫blend space, we blend it using our variables, then we output this. 80 00:05:12,390 --> 00:05:16,140 ‫That becomes the output of our state machine as a whole. 81 00:05:16,140 --> 00:05:21,120 ‫And then it feeds through into the combat animation, which feeds through into our death animation, 82 00:05:21,120 --> 00:05:23,490 ‫which feeds into our final output. 83 00:05:23,820 --> 00:05:30,660 ‫So hopefully now what we'll see when we compile it is actually nothing really has changed because there's 84 00:05:30,660 --> 00:05:32,580 ‫only one state in our state machine. 85 00:05:33,270 --> 00:05:36,780 ‫However, if we're jumping then we can introduce a new state. 86 00:05:36,780 --> 00:05:43,740 ‫For that we go ad state, then we can have airborne as a state, and in this state we won't be playing 87 00:05:43,740 --> 00:05:44,760 ‫the same animations. 88 00:05:44,760 --> 00:05:48,990 ‫We're essentially switching out those animations in the anim graph up. 89 00:05:48,990 --> 00:05:54,210 ‫At this level, we're saying that this node is going to switch to playing different animations when 90 00:05:54,210 --> 00:05:56,070 ‫in the Airborne State. 91 00:05:56,070 --> 00:06:00,450 ‫So we want to go into the Airborne State and make sure we have an animation selected here. 92 00:06:00,450 --> 00:06:05,640 ‫So I'm going to pull off of that result pin and I'm just going to look for a jump. 93 00:06:05,640 --> 00:06:12,630 ‫And particularly I'm going to look for the jump apex combat combat because that has as aiming Apex because 94 00:06:12,630 --> 00:06:19,020 ‫this will be the top of our jump and then we're going to go out of the anim graph, then we're going 95 00:06:19,020 --> 00:06:23,430 ‫to go out to the locomotion level and we'll notice that there's a problem here. 96 00:06:23,520 --> 00:06:28,110 ‫There's no way for us to get to the Airborne State because there isn't a transition that leads us there. 97 00:06:28,410 --> 00:06:34,950 ‫So what we want to do is drag from the border of grounded on to the airborne state and we want to double 98 00:06:34,950 --> 00:06:38,340 ‫click in there because we want to create a transition here. 99 00:06:38,340 --> 00:06:42,090 ‫And I'm just going to do a transition based on a variable which we don't currently have. 100 00:06:42,090 --> 00:06:50,610 ‫So if I go over to my blueprints, add a variable and have an is airborne as a boolean variable in here, 101 00:06:50,610 --> 00:06:58,050 ‫then I can pull that over in to this node editor for our grounded transition. 102 00:06:58,710 --> 00:07:05,910 ‫And then we can hook that up so that what we're saying is this transition is possible when we are airborne 103 00:07:06,270 --> 00:07:11,490 ‫and then we want a converse transition that goes from airborne to grounded. 104 00:07:11,640 --> 00:07:19,410 ‫And if we click on double click on that one, then we can put in a knot node which basically negates 105 00:07:19,410 --> 00:07:25,850 ‫the boolean and then we can put in the is airborne boolean as well. 106 00:07:25,860 --> 00:07:32,280 ‫So that at the end what we've got here, if we go to our anim preview editor tab over to the right, 107 00:07:32,280 --> 00:07:38,310 ‫we can flip this switch and we go into that airborne state playing the airborne animation. 108 00:07:38,310 --> 00:07:44,430 ‫And if we flip it again, we go back in to our grounded locomotion and you can see that all of this 109 00:07:44,430 --> 00:07:46,500 ‫is going to be working with our aim pitch as well. 110 00:07:46,500 --> 00:07:50,820 ‫If I move the aim pitch pointing up, then I hit an airborne. 111 00:07:50,820 --> 00:07:54,530 ‫You can see we keep aiming in the direction that we should be aiming. 112 00:07:54,540 --> 00:08:00,750 ‫Okay, so I've got a mini challenge for you, apart from getting the state machine set up like this, 113 00:08:00,750 --> 00:08:06,690 ‫if you haven't been following along already, what I would like you to try and do is see if you can 114 00:08:06,690 --> 00:08:07,470 ‫find a way. 115 00:08:07,470 --> 00:08:14,130 ‫At the moment when we click is airborne, we get this weird glitching looping of this animation, this 116 00:08:14,130 --> 00:08:15,360 ‫airborne animation. 117 00:08:15,360 --> 00:08:18,810 ‫See if you can make it so that this animation doesn't loop. 118 00:08:18,810 --> 00:08:23,640 ‫So if you can find your way around the anim blueprint, which can be quite hard to navigate and see 119 00:08:23,640 --> 00:08:24,870 ‫if you can find that property. 120 00:08:25,170 --> 00:08:25,680 ‫Welcome back. 121 00:08:25,680 --> 00:08:28,260 ‫So hopefully you've gone and given this a shot. 122 00:08:28,260 --> 00:08:30,510 ‫So where would we start to think about this? 123 00:08:30,510 --> 00:08:33,120 ‫How would we start to navigate around this blueprint? 124 00:08:33,690 --> 00:08:39,600 ‫Well, for a start, we know that this problem is coming from our locomotion state machine. 125 00:08:39,840 --> 00:08:45,210 ‫So let's go in there and we can see that the thing that is playing the state that's currently playing 126 00:08:45,210 --> 00:08:46,680 ‫is the airborne state. 127 00:08:46,680 --> 00:08:52,860 ‫So let's go into that and you can see that the jump apex combat is just looping round and round and 128 00:08:52,860 --> 00:08:55,260 ‫it's clearly creating this problem here. 129 00:08:55,470 --> 00:09:02,490 ‫So if we click on that animation and look at the details, you can see that we have got this loop animation 130 00:09:02,490 --> 00:09:03,540 ‫property set. 131 00:09:03,990 --> 00:09:11,460 ‫If I uncheck that and then recompile our animation blueprint, then I go and hit the is airborne. 132 00:09:11,730 --> 00:09:21,330 ‫You can see it plays that jump apex just once and then it proceeds to hold that animation until we uncheck 133 00:09:21,330 --> 00:09:25,830 ‫the box, at which point it transitions back to our locomotion state machine. 134 00:09:25,830 --> 00:09:29,070 ‫Let's see all of that working if we had a bit of speed, if we were moving. 135 00:09:29,070 --> 00:09:36,030 ‫So here we are running, we add our is airborne, it goes into our jump apex until we are no longer 136 00:09:36,030 --> 00:09:40,350 ‫airborne, at which point we transition back to being running on the ground. 137 00:09:40,350 --> 00:09:41,400 ‫So that's it for this lecture. 138 00:09:41,400 --> 00:09:46,710 ‫We've been introduced to a whole new concept, a lot to take in the idea of an animation state machine 139 00:09:46,710 --> 00:09:52,890 ‫we've seen about states and how we get into them via transitions, and we've seen how that can be driven 140 00:09:52,890 --> 00:09:57,690 ‫by a boolean value to allow us to have a jump state. 141 00:09:57,690 --> 00:10:02,250 ‫In the next lecture, we're going to hook this up to gameplay and refine things further.