WEBVTT 00:01.030 --> 00:01.570 All right. 00:01.570 --> 00:02.740 I got a fun one for you. 00:02.740 --> 00:06.700 This time, I'd like you to make some timelines for our fireball. 00:06.700 --> 00:08.860 So create some timelines. 00:08.860 --> 00:11.020 Maybe one, maybe two. 00:11.020 --> 00:15.640 And I'd like you to make our fireballs fly out and then back in. 00:15.640 --> 00:21.640 So they're going to fly out for a certain distance, at which point they slow down and come back to 00:21.640 --> 00:22.180 aura. 00:22.180 --> 00:27.940 And I'd like you to control their positions directly using values from the timeline. 00:27.940 --> 00:35.050 And I'd also like you to make the fireballs come back to aura, and not just back to their initial launch 00:35.050 --> 00:36.040 location. 00:36.310 --> 00:42.610 That means if aura is running around, then those fireballs are going to probably need to adjust as 00:42.610 --> 00:43.690 they're coming back. 00:43.690 --> 00:46.270 So that's a little bit more of a challenge. 00:46.270 --> 00:52.600 It's a little harder doing this than it is to make the fireballs go back to their initial launch position. 00:52.600 --> 00:57.550 So take that into account, pause the video and conquer this quest now. 01:01.740 --> 01:02.340 Okay. 01:02.340 --> 01:05.850 So I'm going to make some timelines in our fireball blueprint. 01:05.850 --> 01:12.180 But before we do that I'd like to make a function in C plus plus a blueprint callable one that we can 01:12.180 --> 01:13.890 call to start the timeline. 01:13.890 --> 01:20.100 And for that reason I'm going to close down the editor first and go into Aura Fireball. 01:21.350 --> 01:23.090 And make a function. 01:23.090 --> 01:24.560 We can make this public. 01:24.560 --> 01:29.960 It's going to be called void start outgoing timeline. 01:31.420 --> 01:33.520 And I'm going to implement this in blueprint. 01:33.520 --> 01:38.290 So I'm going to make it a new function with blueprint implementable event. 01:38.620 --> 01:40.990 So I don't need to implement it here. 01:40.990 --> 01:44.710 In addition though, there's another thing that I want to expose to blueprint. 01:44.710 --> 01:52.540 And that's an aura projectile we have on hit and on hit is handling, playing a sound, spawning a particle 01:52.540 --> 01:56.890 system, and stopping the looping sound and setting a boolean to true. 01:56.890 --> 02:01.180 This is basically doing everything except for destroy our projectile. 02:01.180 --> 02:03.970 This would be useful to expose to blueprint as well. 02:03.970 --> 02:06.670 So I'm going to make this one blueprint callable. 02:07.390 --> 02:12.310 So give it a new function blueprint callable perfect. 02:12.310 --> 02:20.440 And before launching back up I'm going to go into Aura Fireball and just go into begin play and call 02:20.440 --> 02:24.910 my start outgoing timeline blueprint implementable event. 02:24.910 --> 02:26.590 Just so we started. 02:26.590 --> 02:31.120 And with that we can go ahead and launch the editor. 02:32.890 --> 02:36.910 Okay, so I need to get my fireball open here. 02:36.910 --> 02:40.210 And I need to implement start outgoing timeline. 02:42.040 --> 02:43.570 So here's my event. 02:44.000 --> 02:49.220 And I'd only like to control the location of this fireball on the server. 02:49.220 --> 02:50.450 So first things first. 02:50.450 --> 02:58.760 I'm going to check has authority and switch on that and only do anything if I have authority. 02:58.760 --> 03:01.250 So what are we going to do if we have authority? 03:01.250 --> 03:06.320 Well, I'm going to make a timeline to control my outgoing position. 03:06.320 --> 03:09.530 So I'm going to make a timeline here. 03:11.200 --> 03:13.810 And I'm going to call this outgoing timeline. 03:16.790 --> 03:24.350 So outgoing timeline is going to get a float track and I'm going to call this outgoing track. 03:25.520 --> 03:29.600 An outgoing track can have two points on it, two keys. 03:29.600 --> 03:31.370 So I'm going to add two of them. 03:32.270 --> 03:36.410 And how long do I want these fireballs flying out? 03:36.410 --> 03:41.120 Well, I'm going to make it about one second long, so I'm going to set the length of my timeline to 03:41.120 --> 03:45.290 one and set the first key at time zero. 03:46.050 --> 03:52.620 With a value of zero, and the second key will be at time one with a value of one. 03:53.990 --> 03:56.540 So this will be a normalized curve. 03:56.540 --> 04:03.230 It's going to be something we use along with a maximum distance that we want our fireballs to travel. 04:03.470 --> 04:07.040 I'm going to make it an auto curve and I'm going to shape it like this. 04:07.600 --> 04:14.590 Because I want my fireballs to go out really fast with a high speed and taper off, and then slowly 04:14.590 --> 04:15.100 come back. 04:15.100 --> 04:17.530 Now we're not focused on coming back just yet. 04:17.530 --> 04:19.210 This is just going out. 04:19.690 --> 04:22.330 And how am I going to do this? 04:22.330 --> 04:25.810 Well, I'm going to set actor location somehow. 04:25.810 --> 04:28.360 So if I call set actor location. 04:29.530 --> 04:34.240 We need some location to set in our update, right? 04:34.270 --> 04:37.540 Well, what I'd like to do for my location is. 04:37.540 --> 04:41.260 For one, I need a location to pass in. 04:41.260 --> 04:48.490 So before we start the timeline, I'm going to calculate a location for my target. 04:48.490 --> 04:51.970 At the end of the timeline, I'm going to call it the apex. 04:52.000 --> 04:59.740 Apex generally refers to the highest point in an object's flying trajectory, but I'm referring to the 04:59.740 --> 05:02.260 farthest point out as the apex. 05:02.260 --> 05:07.030 So I'm going to calculate my initial location and my apex location. 05:07.030 --> 05:09.070 So I have a start and an end. 05:09.850 --> 05:14.830 So the start is going to be my current location at the time the timeline started. 05:14.830 --> 05:17.260 So I'm going to call Get Actor location. 05:19.210 --> 05:20.380 And I'm going to store this. 05:20.380 --> 05:24.340 I'm going to promote it to a variable and call it initial location. 05:26.630 --> 05:29.300 Now I also need my apex location. 05:29.330 --> 05:30.860 How am I going to calculate that? 05:30.860 --> 05:34.040 Well, let's get these three nodes here out of the way. 05:34.040 --> 05:37.220 I'm going to take my forward vector. 05:37.490 --> 05:39.830 So get actor forward vector. 05:41.180 --> 05:45.200 And I'm going to multiply this actor forward vector which should be a unit vector. 05:45.200 --> 05:49.820 By the way I'm going to multiply it by a float to scale it out. 05:50.640 --> 05:54.780 Because I want it to be as long as my travel distance. 05:54.780 --> 06:00.420 So I'm going to right click on this second pin, convert it to a float single precision and promote 06:00.420 --> 06:04.170 this to a variable and call this travel distance. 06:06.280 --> 06:11.650 And I can compile and give travel distance a default value if I like. 06:11.950 --> 06:17.470 I'm just going to pick a number, say 1600, but we can tweak that value of course. 06:17.470 --> 06:24.970 But now that I have this vector, I can add this to my initial location and that will give me my apex 06:24.970 --> 06:25.810 location. 06:25.810 --> 06:34.630 So if I take my initial location and I add and I add this vector which points out in the forward direction, 06:34.630 --> 06:40.810 but it's scaled by travel distance, this gives me my apex location, and that's what I'm going to call 06:40.810 --> 06:42.670 it apex location. 06:42.670 --> 06:46.270 So now I have an initial and a destination. 06:46.540 --> 06:52.270 And what I can do is use my outgoing track, which goes from 0 to 1, and I can lerp. 06:52.300 --> 06:54.940 Lerp is a linear interpolation. 06:56.210 --> 07:05.000 If I take my initial location and I drag off and type lerp, I can lerp vector passing in initial location 07:05.000 --> 07:09.680 for a apex, location for B and an alpha. 07:09.710 --> 07:18.020 Now what we get out of this node is a vector between these two, depending on the alpha. 07:18.020 --> 07:22.970 If the alpha is zero, the return value is going to be a initial location. 07:22.970 --> 07:28.400 If the alpha is one, the return value is going to be B apex location. 07:28.520 --> 07:35.240 And if it's say 0.5, then we would get the vector in between these two it's linearly interpolating. 07:35.420 --> 07:43.130 Well I can pass outgoing track into this lerp and take the lerp and pass it into set actor location. 07:43.610 --> 07:51.530 And this allows me to set the location starting at initial going to apex, and will be smoothly going 07:51.530 --> 07:54.050 to it according to our curve. 07:54.050 --> 07:56.240 Let's go ahead and hook this up. 07:56.240 --> 08:00.140 I'm going to just hook up play and I want to see what this looks like. 08:00.140 --> 08:00.500 Now. 08:00.500 --> 08:04.430 First I need to get my projectile movement component and disable it. 08:04.430 --> 08:04.970 Again. 08:04.970 --> 08:09.680 I'm going to go ahead and just put a zero in for initial speed and max speed. 08:09.680 --> 08:15.800 Scroll down and disable everything from auto activate to wears. 08:15.800 --> 08:16.790 Start with tick enabled. 08:16.790 --> 08:17.720 There it is. 08:17.720 --> 08:21.710 And with that we now no longer have projectile movement. 08:21.710 --> 08:24.020 We're now controlling our movement here. 08:24.020 --> 08:25.220 Let's see how it works. 08:25.220 --> 08:28.430 I'm going to go ahead press play and hit the two key. 08:29.290 --> 08:30.130 And there they go. 08:30.130 --> 08:33.040 And they slow to a stop right there. 08:33.070 --> 08:34.450 Pretty fascinating. 08:34.450 --> 08:34.780 Right. 08:34.780 --> 08:36.760 And we can change that travel distance. 08:36.760 --> 08:43.330 That's the magic of having these member variables like this is if I change travel distance to 400, 08:43.330 --> 08:44.830 I accidentally hit four twice. 08:44.830 --> 08:46.330 I'm just going to leave it at 440. 08:46.330 --> 08:47.710 Let's see what it looks like. 08:49.140 --> 08:57.750 So over the space of a second, our projectiles fly out fast at first, but they slow to a stop, right? 08:59.630 --> 09:05.840 So that takes care of the outgoing timeline, but I'm going to want them to come back in as well. 09:06.420 --> 09:11.280 So before we do that, let's put some comments on this section here. 09:11.280 --> 09:16.920 We're going to say store initial and Apex locations. 09:16.920 --> 09:20.250 And this has a lot to do with vectors a lot of yellow. 09:20.250 --> 09:22.440 So I'm going to make this a yellow comment. 09:22.860 --> 09:29.160 And then after we've done this part a very important part here. 09:31.540 --> 09:32.740 And I'll move this. 09:33.740 --> 09:37.880 Let's see if we can overlap as little as possible here. 09:40.800 --> 09:42.210 With our wires. 09:43.470 --> 09:51.630 After this, our timeline is going to execute finished when it's done right and when finished, I'd 09:51.630 --> 09:56.160 like to execute another timeline, one for coming back in. 09:56.160 --> 09:58.830 So I'm going to right click and type timeline. 10:00.180 --> 10:04.380 Scroll all the way to the bottom and add a new timeline and call this one. 10:04.530 --> 10:08.820 Returning or incoming either one returning timeline. 10:09.420 --> 10:15.000 And as soon as Outgoing Timeline is finished, we're going to play the returning timeline, and this 10:15.000 --> 10:21.780 one is going to get a track of its own a float track called Returning Track. 10:23.330 --> 10:26.330 And just like outgoing track, it's going to get two keys. 10:26.330 --> 10:27.620 One, two. 10:27.650 --> 10:33.080 The first one will be at time zero and it'll have a value of zero. 10:33.110 --> 10:39.170 The second is going to get a time of one and it'll have a value of one. 10:39.560 --> 10:44.570 And I can go ahead and normalize it and set the length of the track to one. 10:44.990 --> 10:47.900 So why bother creating a whole timeline for this? 10:47.900 --> 10:50.510 Well we can make this a different shape. 10:50.510 --> 10:58.760 I'm going to make this an auto curve and shape it by grabbing the last key point and put it like this. 11:00.640 --> 11:03.910 So the first curve looks like this. 11:03.910 --> 11:07.540 We're starting off fast and slowing down. 11:07.540 --> 11:10.420 The returning timeline curve starts like this. 11:10.450 --> 11:13.810 It starts off slow and then gets faster. 11:15.500 --> 11:19.370 So with our returning timeline, let's go back to our event graph. 11:19.370 --> 11:23.810 We have our returning track and let's decide how we're going to do this. 11:23.810 --> 11:29.540 I know for sure I'm going to be using set actor location, so I'm going to go ahead and hook that up 11:29.540 --> 11:30.650 to update. 11:31.240 --> 11:33.820 But how am I going to lerp this one? 11:33.820 --> 11:35.980 Well, I can duplicate lerp. 11:37.720 --> 11:41.680 And we're starting off at the apex location this time. 11:41.680 --> 11:44.710 So that's going to be a but what's B? 11:44.740 --> 11:49.870 Well, B needs to be the actor that we're returning back to. 11:50.140 --> 11:53.080 So how do we know what that actor is. 11:53.110 --> 11:55.480 Well we're going to have to set it somehow. 11:55.570 --> 12:00.970 So I'd like to add a variable to our fireball that we can set when we spawn it. 12:00.970 --> 12:01.750 Let's do that. 12:01.750 --> 12:03.940 Let's go ahead and close the editor down. 12:03.940 --> 12:09.010 We'll save all and we'll go back to our fireball and we'll add an actor. 12:09.010 --> 12:13.960 So it's going to be a public variable just so we can set it from outside the class. 12:13.960 --> 12:16.180 Let's make it a t object pointer. 12:16.930 --> 12:18.970 And this will be an A actor. 12:19.330 --> 12:22.870 And we're going to call this return to actor. 12:23.230 --> 12:27.820 And we'll give it a U property and make it blueprint read only. 12:28.030 --> 12:30.640 And we'll set this as soon as we spawn it. 12:30.640 --> 12:33.040 So we'll go back to Aura Fire Blast. 12:33.040 --> 12:38.020 And as soon as we've spawned the fireball, we're setting its damage effect params. 12:38.020 --> 12:39.730 We're also going to set. 12:40.850 --> 12:42.830 Its return to actor. 12:43.040 --> 12:44.990 And what are we going to return to? 12:44.990 --> 12:46.130 Well that's easy. 12:46.640 --> 12:50.480 Get avatar actor from actor info. 12:50.840 --> 12:53.840 And with that, we now have a valid return to actor. 12:53.840 --> 12:55.550 We've exposed it to blueprint. 12:55.820 --> 12:58.820 Now we can use it in our event graph. 13:00.490 --> 13:01.150 Okay. 13:01.150 --> 13:03.100 So we're going to go ahead and open. 13:03.550 --> 13:11.080 And now in our lerp we can use Return to actor and we can get its actor location. 13:12.270 --> 13:13.980 With Get Actor location. 13:14.620 --> 13:19.180 We can hook that in for B and our track is going to go into Alpha. 13:26.100 --> 13:28.140 So we can bring this up here. 13:35.490 --> 13:38.100 I'm just tidying things up a bit. 13:38.820 --> 13:41.340 And this will go into new location. 13:41.700 --> 13:42.840 Now here's the thing. 13:42.840 --> 13:45.600 As soon as we're done, I want to blow up. 13:47.140 --> 13:55.600 So I'm going to place a branch right here after we've set the active location and blow up under a certain 13:55.600 --> 13:56.110 condition. 13:56.110 --> 13:57.730 Now, what is that condition? 13:57.730 --> 14:04.450 Well, I want a specific distance that these should blow up as soon as they come back within that distance. 14:04.450 --> 14:09.520 So I'm going to add a new variable and call this explode distance. 14:10.060 --> 14:11.650 It's going to be a float. 14:11.800 --> 14:14.380 I can compile and give it a value. 14:15.190 --> 14:18.550 And I'll just make it say 250. 14:18.550 --> 14:24.670 So when our fireballs are coming back, as soon as they're close enough, close enough. 14:24.670 --> 14:28.150 Being 250 away, we're going to blow up. 14:28.150 --> 14:30.850 So let's check that distance. 14:31.430 --> 14:35.420 So first of all, we need to check the distance between this fireball. 14:36.560 --> 14:39.200 That's get actor location 14:41.000 --> 14:42.260 minus. 14:42.870 --> 14:44.190 Minus what? 14:44.220 --> 14:48.030 Minus the location of return to actor. 14:51.080 --> 14:54.020 And after we have this vector, we get its length. 14:54.140 --> 14:56.720 So we use vector length. 14:58.010 --> 14:59.090 And we check this length. 14:59.090 --> 15:02.390 We say, is this less than or equal to? 15:03.540 --> 15:06.000 And we have our explode distance. 15:07.180 --> 15:11.740 This can go into our branch and this could be a blueprint, pure function. 15:11.740 --> 15:12.880 We can collapse. 15:12.880 --> 15:19.660 The function we can call this is within explode distance. 15:20.170 --> 15:25.600 And we can take this function and make it a blueprint pure by checking pure like that. 15:27.700 --> 15:29.140 So that looks nice. 15:30.240 --> 15:35.040 So if we should explode, if is within explode distance. 15:35.040 --> 15:37.140 Well, we have on hit, don't we? 15:40.130 --> 15:43.280 That's going to do lots of things for us. 15:43.280 --> 15:46.550 It's going to make our explosion happen. 15:48.190 --> 15:50.530 Now all of this happens on the server. 15:50.530 --> 15:55.360 So if on hit happens then we can just destroy actor. 15:57.270 --> 16:01.110 Let's see how this all works with our incoming timeline. 16:01.860 --> 16:05.400 I'm going to save all first and press the two key. 16:06.690 --> 16:09.390 And that looks amazing. 16:12.520 --> 16:17.500 And the cool thing is, if we're running around, it looks even better because check this out. 16:18.550 --> 16:19.450 Boom. 16:24.480 --> 16:25.650 That looks so good. 16:25.650 --> 16:32.100 Now I would like to change the travel distance because 440 is a little low. 16:32.130 --> 16:33.840 I'm going to try 800. 16:35.580 --> 16:37.530 I might even have it even more than that. 16:37.530 --> 16:37.830 Oops. 16:37.830 --> 16:39.210 Wrong spell. 16:39.390 --> 16:40.680 That's the one. 16:41.920 --> 16:46.960 Look at that and the explode distance is a little high, I think. 16:46.960 --> 16:54.580 So I'm going to go ahead and change the explode distance from 250 to let's try 150. 16:58.860 --> 17:00.150 I like it. 17:01.320 --> 17:04.080 Now things are looking good visually. 17:04.840 --> 17:06.670 But we don't cause any damage. 17:06.670 --> 17:12.760 We'll see that they can pass through enemies, these fireballs, and they can even explode next to them. 17:12.760 --> 17:14.470 Nothing really happens. 17:14.470 --> 17:17.920 So we're going to need to make these fireballs functional. 17:17.920 --> 17:20.530 But visually, this is looking pretty. 17:20.530 --> 17:21.700 Pretty nice. 17:24.940 --> 17:29.260 So awesome if you got through this whole challenge, congratulations! 17:29.260 --> 17:30.670 I'm really proud of you. 17:30.670 --> 17:32.380 And if not, don't worry about it. 17:32.380 --> 17:34.090 We got fireballs now. 17:34.120 --> 17:39.100 Things are looking great and we'll continue in the next video.