WEBVTT 00:06.840 --> 00:07.950 Welcome back. 00:08.470 --> 00:14.080 Now our Arcane Shards ability is going to spawn some shards, right? 00:14.080 --> 00:19.060 And I'd like my shards ability to spawn multiple shards. 00:19.060 --> 00:27.550 And when I say multiple shards, let's go into assets effects, arcane shards and open up this Niagara 00:27.550 --> 00:28.390 system. 00:28.510 --> 00:33.190 And in preview scene settings, I'm going to show the floor just so I can see what it looks like on 00:33.190 --> 00:34.120 the ground. 00:34.120 --> 00:39.310 I'm going to uncheck Show environment, and I'm going to set the background to a darker color so that 00:39.310 --> 00:42.880 I can see really more closely what it's going to look like. 00:42.970 --> 00:47.320 Now, this system here, I'm referring to that as a shard. 00:47.320 --> 00:49.330 Or we could call it a group of shards. 00:49.330 --> 00:56.740 Now I'd like to spawn one of these, and at level one, I think our ability can spawn it right there 00:56.740 --> 00:58.750 in the center of our decal. 00:58.750 --> 01:04.780 But at say, level two, I'd like to spawn two of these, and at level three, I'd like to spawn three 01:04.780 --> 01:05.290 of them. 01:05.290 --> 01:10.990 And for arcane shards, I'd like to go all the way up to say, level 10 or 11. 01:10.990 --> 01:18.010 I'd like to spawn a whole bunch of these, and I'd like them to be spawned at roughly evenly distributed 01:18.010 --> 01:25.660 locations, and depending on how many were spawning, I'd like them to spawn starting at the inside 01:25.660 --> 01:28.390 of the circle and propagating outward. 01:28.390 --> 01:30.760 So how is that going to work? 01:30.760 --> 01:31.540 Now? 01:31.540 --> 01:38.950 One way is to calculate these locations, to spawn these at procedurally or with some kind of algorithm. 01:38.950 --> 01:40.300 That's one way. 01:40.330 --> 01:47.500 Another way is to have some collection of points that we've handcrafted, rather than using lines of 01:47.500 --> 01:51.550 code to calculate mathematically where we're spawning things. 01:51.550 --> 01:57.520 Now, I'd like to use the approach of having a collection of points that I've placed out manually. 01:57.520 --> 02:02.770 In other words, I'd like to have some kind of actor that contains a bunch of points. 02:02.770 --> 02:06.400 Now, this method has a couple of advantages. 02:06.400 --> 02:14.260 One is that obviously it looks better when points are hand placed rather than calculated with some kind 02:14.260 --> 02:15.310 of algorithm. 02:15.310 --> 02:20.890 Not necessarily, but in general, if you can hand place points, it looks good. 02:20.890 --> 02:27.910 And another thing is our point collection, if it's an actor we create can have its own functions that 02:27.910 --> 02:29.890 can calculate things. 02:30.460 --> 02:34.570 For instance, let's say that we cast our spell on the stairs. 02:35.180 --> 02:42.320 If I want a collection of points, I want to make sure those points have correct locations, especially 02:42.320 --> 02:43.340 their elevation. 02:43.340 --> 02:47.510 I want them to not be spawned underneath the stairs. 02:47.510 --> 02:53.150 I don't want some of them to be spawned at the top of the stairs, and then others in the air above 02:53.150 --> 02:54.350 the bottom steps. 02:54.350 --> 02:59.210 I'd like them to be spawned on the stairs and perhaps even oriented correctly. 02:59.210 --> 03:05.300 Or if we're on a sloped surface, I'd like to spawn these particle systems on the ground. 03:05.300 --> 03:12.770 And so for that reason, a point collection actor can be useful because it can perform some sort of 03:12.770 --> 03:18.860 line trace down to the ground and get the ground location corresponding to those spawn points. 03:18.860 --> 03:25.280 So for that reason, I'd like to make a point collection actor, and this is going to just be an actor. 03:25.280 --> 03:32.990 We're going to stick it in the actor folder so I can go to C plus plus classes or a public actor and 03:32.990 --> 03:34.160 we can put it here. 03:34.760 --> 03:37.520 So I'm going to go ahead and make a new C plus plus class. 03:37.520 --> 03:42.680 I'm going to choose actor and I'm going to call this point collection. 03:44.120 --> 03:46.040 So I'm going to create this class. 03:46.040 --> 03:51.170 I'm going to go ahead and close down the editor, save all my changes. 03:51.170 --> 03:55.760 And I'm going to get this point collection actor open. 03:55.760 --> 04:02.900 I'll go ahead and close all tabs for now and open up Actor Point Collection. 04:02.900 --> 04:07.190 And we'll go ahead and get both header and CPP files open. 04:07.190 --> 04:09.920 So let's clean up this file. 04:10.160 --> 04:16.580 I'll go ahead and remove those comments that I don't like, and move the tick function up to the constructor 04:16.580 --> 04:19.340 and delete that third public section. 04:20.440 --> 04:25.360 We can also remove comments from the cpp file. 04:25.360 --> 04:28.900 And actually my point collection doesn't need to tick. 04:28.900 --> 04:34.750 So I'm going to set primary actor tick be can never tick to false and just remove the tick function 04:34.750 --> 04:35.680 altogether. 04:35.680 --> 04:37.660 No need to override it at all. 04:38.290 --> 04:40.150 And we have a point collection. 04:40.450 --> 04:43.450 Now a point collection should have points. 04:43.450 --> 04:46.420 It should have points that have their own locations. 04:46.420 --> 04:53.500 And one of the most simple types of components that has a location is the scene component. 04:53.500 --> 04:58.960 So we can have ourselves a scene component for each point that we'd like. 04:58.960 --> 05:02.980 So what I want to do is create a whole bunch of scene components. 05:02.980 --> 05:13.000 And I could put these in a private section, and these can be t object pointers, each to a U scene 05:13.000 --> 05:13.900 component. 05:15.790 --> 05:18.940 So in other words, I'll have point one. 05:18.940 --> 05:24.940 I can just use DT one I can actually start at zero because we're programmers, and programmers start 05:24.940 --> 05:27.220 indexing things at zero, don't they? 05:27.220 --> 05:30.700 Unless you program in Lua if you've ever heard of that language. 05:30.700 --> 05:32.500 But that's beside the point. 05:32.500 --> 05:33.790 Let's make a bunch of points. 05:33.790 --> 05:40.600 Now I want about 11 of these, so I'm going to go ahead and just copy paste 11 times. 05:40.600 --> 05:46.300 But I suppose it would be smarter to add a uproperty and copy paste that too. 05:46.300 --> 05:50.020 So I'm going to go ahead and give this blueprint read only. 05:51.580 --> 05:56.950 And when autocomplete isn't working that's an indicator that you have a typo. 05:57.670 --> 06:01.120 So blueprint read only I'll make it visible anywhere. 06:01.120 --> 06:08.440 And if it's going to be blueprint read only, then it should either have meta allow private access like 06:08.440 --> 06:09.190 this. 06:12.730 --> 06:13.990 Equals true. 06:14.110 --> 06:19.930 That would allow us to have a blueprint read only in the private section, or we could just let it be 06:19.930 --> 06:20.860 protected. 06:20.890 --> 06:25.150 I tend to opt for the second option, so we'll go ahead and do that. 06:26.370 --> 06:28.710 So now we have point zero. 06:28.740 --> 06:30.240 We have point one. 06:30.240 --> 06:33.750 And we can paste this a few more times. 06:33.750 --> 06:35.670 I think I'd like to have up to point ten. 06:35.670 --> 06:37.710 So let's do this. 06:43.560 --> 06:46.650 So we have ten scene components. 06:46.650 --> 06:50.370 In addition to that, I'd like to keep these in an array. 06:50.370 --> 06:53.820 And that's going to make them easy to iterate over. 06:53.820 --> 06:56.370 So I'm going to make a T array that holds. 06:56.370 --> 06:58.260 You seen component pointers. 06:58.260 --> 07:01.890 So you seen component pointer. 07:01.890 --> 07:06.420 And this is going to be called immutable points. 07:06.690 --> 07:12.810 Pts immutable in a sense that I don't want to ever change this. 07:14.730 --> 07:16.920 I want to keep it unchanged. 07:16.920 --> 07:21.060 And this is going to be blueprint read only visible anywhere. 07:21.060 --> 07:28.890 And we'll just add all of our scene components to this right off the bat as we construct them. 07:28.890 --> 07:33.450 So to the constructor we're going to go over to the constructor here. 07:33.450 --> 07:37.020 And we're going to construct each of these starting at point zero. 07:37.020 --> 07:43.530 So point zero equals we're going to use Createdefaultsubobject with you scene component. 07:47.090 --> 07:50.600 And we're just going to give these each the name. 07:51.310 --> 07:53.680 That corresponds to their variable name. 07:53.680 --> 07:55.420 So the same internal name. 07:55.420 --> 07:57.250 We're going to add it to a mutable points. 07:57.250 --> 08:01.120 So a mutable points dot add point zero. 08:01.360 --> 08:06.310 And we're also going to set point zero as the root component. 08:06.310 --> 08:09.820 So I'm going to say set root component point zero. 08:11.970 --> 08:14.790 And after that I'm going to construct all the others. 08:14.790 --> 08:18.990 So I'm going to copy these two lines and paste them and change this to point one. 08:20.790 --> 08:24.240 So that I'm creating and adding it to a mutable points. 08:24.240 --> 08:30.270 The difference for this is I'm going to take point one and call setup attachment, and we're going to 08:30.270 --> 08:32.070 call get root component here. 08:33.150 --> 08:39.630 After this we can copy this a few more times until we have all the way up to point ten. 08:39.630 --> 08:40.950 So let's do that. 09:02.450 --> 09:05.150 Okay so that's ten points. 09:05.600 --> 09:07.460 So that's great. 09:07.460 --> 09:12.350 Our point collection is just a glorified array with some perks right. 09:12.350 --> 09:17.090 It has seen components with each their own location in space. 09:17.090 --> 09:22.610 Seen components here are going to be a little bit more valuable to me than just f vectors because I 09:22.610 --> 09:27.380 can place these wherever I want in relation to the root component. 09:27.960 --> 09:33.960 Now, in addition to having a bunch of points, I'd like a nice function that can return an array of 09:33.960 --> 09:35.700 these only. 09:35.700 --> 09:42.780 I'd like to return an array that's a copy of these scene components, or at least an array of locations 09:42.780 --> 09:45.150 in space that represent these. 09:45.150 --> 09:50.970 But the reason I'd like to return an array is because I want to be able to get all these points on the 09:50.970 --> 09:54.630 ground, making sure that they're not below the ground. 09:54.630 --> 09:55.650 Above the ground. 09:55.650 --> 09:58.080 We're going to be performing some line traces. 09:58.080 --> 10:03.270 So I'm going to create a public function here that can get these points. 10:03.270 --> 10:10.860 So whether we return an array of scene component copies or just an array of locations, it doesn't really 10:10.860 --> 10:11.790 matter. 10:11.790 --> 10:19.020 I like the idea of a function returning an array of scene components because they have location, but 10:19.020 --> 10:20.670 also rotation. 10:20.670 --> 10:28.080 So if we have a rotation and we'd like to angle our particle systems that we spawn based on, say, 10:28.080 --> 10:33.570 the normal of the ground, well, we can use scene components for their rotations as well. 10:33.570 --> 10:41.640 So I'm going to make a function here in the public section that returns a 2D array of you scene component 10:41.640 --> 10:42.570 pointers. 10:45.430 --> 10:49.060 And we're going to call this get ground points. 10:50.480 --> 10:55.490 Now get ground points is going to need a couple of pieces of information. 10:55.490 --> 10:58.250 One, it needs to know the ground location. 10:58.250 --> 11:01.100 So we're going to pass that in as a const vector. 11:03.560 --> 11:05.480 We'll call it ground location. 11:08.570 --> 11:15.770 In addition to this, I'd like to be able to pass in an integer into this function to get a limited 11:15.770 --> 11:18.470 number of the points in the collection. 11:18.500 --> 11:23.690 For example, I'd like the first three that are closest to the center, and so on. 11:23.690 --> 11:29.420 So I'm going to go ahead and make an int 32 input parameter here called num points. 11:30.290 --> 11:36.650 And then I'd like to be able to override the rotation as a your value. 11:36.650 --> 11:40.580 So I'm going to say your override and that'll be a float. 11:40.580 --> 11:45.500 But if we don't pass this in I'd like it to be initialized to zero by default. 11:45.500 --> 11:48.260 And this can be a blueprint pure function. 11:48.260 --> 11:51.410 I'm going to make it you function blueprint pure. 11:51.410 --> 11:59.210 As every time we call this, we're going to want it to be executed afresh, anew, a different time. 11:59.210 --> 12:01.670 So let's go ahead and generate the definition. 12:02.980 --> 12:07.630 And what exactly is this get ground points going to do for us? 12:07.630 --> 12:14.620 Well, the first thing is, if I call the function and I pass in num points and num points is more than 12:14.620 --> 12:21.340 how many points I have, I'm going to punish the user who called this function with a nice crash. 12:21.340 --> 12:26.440 So I'm going to say check f, I'm going to say immutable points dot num. 12:26.920 --> 12:30.940 And I want to make sure that this is greater than or equal to num points. 12:30.940 --> 12:34.360 If it is greater than or equal to num points, we're good. 12:34.360 --> 12:40.420 Otherwise we're going to crash with a nice nasty crash log message. 12:40.420 --> 12:48.640 We're going to say attempted to access immutable points out of bounds. 12:51.640 --> 12:55.690 Okay, now that we're done being nasty, let's continue. 12:55.690 --> 13:00.190 And what I'm going to do is first and foremost make a T array. 13:00.220 --> 13:03.520 That's a copy of my immutable points. 13:03.520 --> 13:11.200 So if I shuffle them around in my array, for example, or I remove anything from the array, at least 13:11.200 --> 13:13.960 my original array won't be touched. 13:13.960 --> 13:17.170 So this will be a t array of you seen component pointers. 13:17.170 --> 13:19.630 And I'm going to call this array copy. 13:20.830 --> 13:24.280 Now what I'm going to do is loop through my immutable points array. 13:24.280 --> 13:31.210 I'm going to say for you seen component pointer I'm going to call it t short for point. 13:31.210 --> 13:33.850 And I'm looping through immutable points. 13:33.850 --> 13:41.920 And each iteration of the for loop I'm going to check if array copy dot num. 13:43.930 --> 13:45.940 Is greater than num points. 13:46.780 --> 13:50.170 If it is, we should just return array copy. 13:54.500 --> 13:57.980 As there's no point in continuing, right? 13:57.980 --> 14:03.380 Because array copy now contains greater than num points elements. 14:05.030 --> 14:06.320 After that. 14:06.320 --> 14:12.800 What I'd like to do is get the location of all the points in my immutable points array. 14:12.830 --> 14:14.840 All of my scene components. 14:14.840 --> 14:25.250 But I'd also like to rotate all of my points by the amount of your override that I'm passing in. 14:25.250 --> 14:31.640 And the way that I'm going to set this up is point zero is at the center, so we don't need to rotate 14:31.640 --> 14:36.710 point zero, but I want to rotate all the other points relative to point zero. 14:36.710 --> 14:40.400 And I'm just going to have points one through ten. 14:40.580 --> 14:45.680 Get farther and farther away based on their order away from zero. 14:45.680 --> 14:53.270 So what I'm going to do is I'm going to say if point is not equal to point zero. 14:54.860 --> 14:59.450 Because there's no point in rotating point zero. 14:59.480 --> 15:06.020 So what I'm going to do is make an f vector called two point, and this is going to be the vector from 15:06.020 --> 15:07.790 the center to the point. 15:07.790 --> 15:15.530 So I'm going to take point get component location minus point zero. 15:15.530 --> 15:17.300 Get component location. 15:18.080 --> 15:22.460 So I have the vector from the center to point and I'm going to rotate it. 15:22.460 --> 15:32.630 So I'm going to take two points and set it equal to 2.. rotate angle axis. 15:32.630 --> 15:39.260 And I'm going to rotate about the up vector an amount equal to your override. 15:39.260 --> 15:43.010 So I'm going to say your override as the amount to rotate. 15:43.010 --> 15:45.260 And I'm going to use f vector. 15:46.580 --> 15:47.630 Up vector. 15:49.010 --> 15:55.670 And now that I've rotated this two point vector, then I can go ahead and set my point location. 15:55.670 --> 16:05.630 I could say point set world location, and I can get my point underscore zero and get its location. 16:05.630 --> 16:08.360 So get component location. 16:08.360 --> 16:13.130 Of course this is also the same as get actor location because this is the root component. 16:13.130 --> 16:18.290 But we can get that actor location and add two point to it. 16:18.290 --> 16:26.270 And now we'll be repositioning this point such that we've rotated it by our yaw override. 16:26.840 --> 16:30.680 This allows us to get some variation in the rotation of our point collection. 16:31.370 --> 16:38.090 Now, after doing that, I'd like to perform a line trace straight down to the floor to get the ground 16:38.090 --> 16:39.080 location. 16:39.560 --> 16:47.870 So for that, we need a trace start and a trace end, which will be raised and lowered locations, respectfully. 16:48.350 --> 16:54.680 So I'm going to make a const f vector and call this raised location. 16:55.320 --> 16:57.450 Now this is going to be an f vector. 16:57.450 --> 16:59.970 I'm going to use the f vector constructor. 16:59.970 --> 17:07.770 But I'm going to initialize it with x, y, z components starting with point get component location 17:07.770 --> 17:11.070 dot x so it can have the same x. 17:11.580 --> 17:15.660 I'm also going to use point get component location dot y for the y. 17:15.690 --> 17:17.700 So dot y there. 17:18.090 --> 17:20.730 But for z I'm going to add some to it. 17:20.730 --> 17:26.430 I'm going to use point get component location dot z plus 500. 17:27.860 --> 17:34.310 I don't want to go too far beyond 500 above this points location for the start of my trace. 17:34.310 --> 17:40.700 The end of the trace is going to end up below, so it's going to be called lowered location. 17:41.180 --> 17:47.030 And for this the Z is going to be the original Z of the point -500. 17:47.030 --> 17:50.630 So we start 500 above and we end 500 below. 17:50.630 --> 17:53.150 And now we can line trace between these two. 17:53.180 --> 17:59.600 So I'm going to make a line trace which requires an f hit result I'm going to call it hit result. 18:00.730 --> 18:08.560 And of course, if we line trace, we just might trace down and hit an enemy or any kind of thing we 18:08.560 --> 18:09.760 don't want to hit. 18:09.760 --> 18:15.130 And luckily there's a function to get all live players within radius. 18:15.130 --> 18:19.900 It's a function we added to you or a ability system library. 18:19.900 --> 18:23.500 And we call this get live players within radius. 18:23.500 --> 18:28.690 And this can take a world context object that can be this. 18:28.690 --> 18:32.500 And it also takes an array of overlapping actors. 18:32.950 --> 18:35.320 I'm going to make an array to pass in. 18:35.620 --> 18:38.680 So it's a T array of a actors. 18:41.740 --> 18:42.790 Pointers, of course. 18:42.790 --> 18:45.160 And I'm going to call this ignore actors. 18:45.250 --> 18:48.190 And I'm going to pass ignore actors in here. 18:49.000 --> 18:49.630 Why? 18:49.660 --> 18:55.120 Because get live players within radius will fill that in with all live players. 18:55.120 --> 18:59.230 And that's basically anything that implements the combat interface that isn't dead. 18:59.230 --> 19:00.940 So I'm going to pass that in. 19:00.940 --> 19:05.620 Now this function itself requires an array of actors to ignore. 19:05.650 --> 19:08.440 That's not going to be my ignore actors. 19:08.440 --> 19:11.920 I'm going to ignore nothing with get live players within radius. 19:11.920 --> 19:17.860 So I'm going to make a t array of a actor pointers, but an empty one. 19:18.340 --> 19:22.480 So passing in an empty array there and we need a radius. 19:22.480 --> 19:25.390 So I'm just going to pass in 1500. 19:26.170 --> 19:28.630 We can make that a member if we want. 19:28.630 --> 19:31.720 And then it needs a sphere origin. 19:31.720 --> 19:34.450 We're going to use get actor location again. 19:34.450 --> 19:37.510 That's the same as the point zero location. 19:37.600 --> 19:44.500 But the point of this is to get all the live players within radius and fill them in to my ignore actors 19:44.500 --> 19:45.160 array. 19:45.160 --> 19:45.790 Why? 19:45.820 --> 19:50.950 Because I'm going to now use this as my ignore actors for my line trace. 19:50.980 --> 19:52.360 Pretty clever right? 19:52.360 --> 19:59.380 So what I can do now is I can perform a line trace, and the particular line trace that I'd like to 19:59.380 --> 20:09.520 use is line trace by profile, so that I can only trace against objects that have a specific collision 20:09.520 --> 20:10.420 profile. 20:10.420 --> 20:15.760 And profiles are things like block all, block all dynamic, things like that. 20:16.420 --> 20:17.890 So here's what I'm going to do. 20:17.890 --> 20:24.460 I'm going to call get World Line Trace single by profile. 20:25.030 --> 20:27.430 The first input is the hit results. 20:27.430 --> 20:29.140 So I'm going to pass in hit result. 20:30.270 --> 20:33.090 The second input is the trace start that's going to be raised. 20:33.090 --> 20:34.050 Location. 20:34.350 --> 20:38.040 Next is the trace end that's going to be lowered location. 20:38.730 --> 20:43.350 After that we have the profile which is a profile F name. 20:43.440 --> 20:46.470 And I'm going to trace against block all. 20:49.190 --> 20:51.560 And now we need collision query params. 20:51.560 --> 20:55.550 We can just create some f collision query params here. 20:59.850 --> 21:02.130 I'm going to call these query params. 21:05.060 --> 21:08.240 And this is where I can use my ignore actor's array. 21:08.240 --> 21:10.520 So I'm going to take query params. 21:12.020 --> 21:19.910 Dot, add, ignore or ignored actors and pass in ignore actors. 21:21.080 --> 21:25.760 And we can pass query params in as the last of the inputs for this. 21:25.790 --> 21:32.450 Now that we're tracing and we're ignoring all of the live players within a radius we specified, well, 21:32.450 --> 21:39.560 this is great because now we can take this line trace and get that location from its hit result. 21:39.950 --> 21:43.670 And really, I only care about the Z location of it. 21:43.670 --> 21:48.920 So I'm going to make a new const fvector called adjusted location. 21:48.920 --> 21:52.250 And it's going to be a new f vector. 21:53.240 --> 21:56.510 And I'm going to use the points x and y. 21:56.510 --> 22:02.810 So I'm going to use point get component location dot x point get component location dot y. 22:02.840 --> 22:04.910 I'm going to copy those and paste them here. 22:05.330 --> 22:11.240 And for the Z I'm going to use my hit results dot impact point. 22:11.760 --> 22:12.870 Dot z. 22:13.560 --> 22:18.960 So the only thing that really matters from our line trace is that z location. 22:19.470 --> 22:21.240 Now, after all this. 22:21.270 --> 22:29.640 Now that we have an adjusted location, I'm going to take my point and call set world location passing 22:29.640 --> 22:31.380 in my adjusted location. 22:33.380 --> 22:39.380 Now I can also set its rotation based on that hit result because we have the impact normal. 22:39.380 --> 22:44.000 So what I can do is take point and call set world rotation. 22:44.000 --> 22:46.250 And this needs to be a rotator. 22:46.250 --> 22:48.680 So how do I get a rotator from a vector. 22:48.680 --> 22:52.430 Well I can use you Kismet math library. 22:52.430 --> 22:56.540 And there's a handy function called make wrote from Z. 22:56.540 --> 23:03.020 And this can take in an f vector I can use hit result dot impact normal. 23:03.020 --> 23:08.720 The normal is the vector from the ground straight out perpendicular. 23:08.720 --> 23:14.420 We call it orthogonal when we use 3D vectors to that face that was hit. 23:14.420 --> 23:19.010 And this is actually you kismet math library, not just you kismet math. 23:19.010 --> 23:22.760 I thought I autocompleted it, but looks like I didn't. 23:23.180 --> 23:26.090 Now by the end of this point has been adjusted. 23:26.090 --> 23:31.190 It's been rotated potentially, and it's been elevated or lowered potentially. 23:31.670 --> 23:36.830 So after doing this I'd like to add it to my array copy. 23:38.150 --> 23:39.980 So array copy dot add. 23:39.980 --> 23:41.360 And I'm going to add the point. 23:41.390 --> 23:46.190 Now this doesn't mean that we're creating a copy of the scene component. 23:46.190 --> 23:47.180 We're not. 23:47.180 --> 23:49.700 There's only ten scene components here. 23:49.700 --> 23:51.170 We're not creating any new ones. 23:51.170 --> 23:53.990 We're just moving around those scene components. 23:54.440 --> 23:59.870 So they start off at their original positions, we move them and we return an array that contains some 23:59.870 --> 24:00.410 of them. 24:00.410 --> 24:03.020 Not all of them, just some of them. 24:03.020 --> 24:07.550 Just enough for our needs determined by num points. 24:07.970 --> 24:11.720 And we're looping over all of these points starting at zero. 24:11.720 --> 24:19.700 And each time we're adding one to our array copy, and we're going to return as soon as our array copy 24:19.700 --> 24:21.800 becomes equal to num points. 24:21.800 --> 24:25.460 We said greater than we could use greater than or equal to here. 24:25.460 --> 24:26.180 Really. 24:26.180 --> 24:31.820 Because once this array contains num points we're ready to return it. 24:31.820 --> 24:35.720 And then we can use those scene components in any way we want. 24:36.430 --> 24:38.740 So now we can see how this works. 24:38.740 --> 24:42.550 Of course, our get ground points needs to return an array. 24:42.550 --> 24:46.840 So by the very end of this we have to actually return array copy. 24:47.880 --> 24:50.820 And now that this returns something, we can try this out. 24:50.820 --> 24:53.190 Let's go ahead and compile and launch the editor. 24:54.360 --> 24:56.490 All right, so back in the editor. 24:56.520 --> 24:59.400 Looks like I can close arcane shards there. 24:59.400 --> 25:01.860 I'm going to close our character. 25:01.860 --> 25:04.800 And here in my Arcane shards gameplay ability. 25:05.580 --> 25:10.170 I can try to use my point collection, but I'm going to close project settings. 25:10.170 --> 25:16.050 And before we go and create a point collection, I'm going to make a blueprint based on our point collection 25:16.050 --> 25:16.500 class. 25:16.500 --> 25:20.310 So let's go to blueprints I'm going to go to. 25:21.090 --> 25:23.310 Ability, system or abilities. 25:23.310 --> 25:25.050 Arcane arcane shards. 25:25.050 --> 25:29.910 And I'm going to make a new blueprint here, and I'm going to make this based on my point Collection 25:29.910 --> 25:30.750 class. 25:33.540 --> 25:36.450 And I'll just call this BP Point Collection. 25:40.550 --> 25:42.380 So I'm going to open my point collection. 25:42.380 --> 25:49.670 Now here are my scene components and you can't really see them unless you select them. 25:49.670 --> 25:51.230 You can move them around. 25:51.770 --> 25:58.100 I'd like to position these by hand, and I'd like to position them in order closest to the origin. 25:58.100 --> 26:00.200 The lower their number is. 26:00.440 --> 26:05.090 So what I'm going to do is select point one and move it. 26:05.090 --> 26:09.740 But before I do that, I want to be able to see all of these relative to each other. 26:09.740 --> 26:15.110 So I'm going to take each one, select it and add a billboard. 26:15.110 --> 26:18.140 And that's going to allow me to see that component. 26:18.140 --> 26:21.800 So I'm going to add a billboard to point one. 26:21.800 --> 26:23.690 And then I'm going to move point one. 26:23.690 --> 26:29.030 Now if you add a billboard to point one, don't go moving the billboard, because point one will just 26:29.030 --> 26:33.140 stay there and then they'll have an offset which will just confuse you. 26:33.170 --> 26:35.960 You're going to want to move point one instead. 26:35.960 --> 26:40.640 But before I do that, I'm going to change the billboard texture. 26:41.300 --> 26:47.390 If I search for target, I can use target icon that looks a little bit cooler. 26:48.050 --> 26:51.350 So I can select one of these target icons. 26:51.350 --> 26:56.990 There's one in editor materials in the engine and there's one in engine debug materials. 26:57.540 --> 27:02.790 So now that I have that, I can select point one and I can move it. 27:03.610 --> 27:08.890 Now you can use snapping if you want snapping, or you can just move these by hand. 27:08.920 --> 27:14.320 I'm going to move it a little bit without snapping and just to see where that origin is, I'm going 27:14.320 --> 27:18.850 to take point zero and I'm going to add a billboard to point zero as well. 27:20.990 --> 27:23.270 And I'll go ahead and change this one as well. 27:23.270 --> 27:26.000 I'm going to search for target point or just target. 27:26.000 --> 27:28.460 And here's a target icon spawn. 27:28.460 --> 27:34.490 It's a little bit different and we can just use that to distinguish that middle point. 27:35.060 --> 27:38.900 Now point one over here is 100 units away. 27:38.900 --> 27:44.900 And really, we just kind of need to know how big those shard particles are. 27:44.930 --> 27:52.250 And so in order to see that what we can do is we can drag one in, we can go to effects arcane shards, 27:52.250 --> 27:54.470 and we can bring in arcane shards. 27:54.470 --> 28:02.120 We can set arcane shards at a specific location, let's just say zero zero for x, y. 28:02.420 --> 28:06.380 And if we duplicate this and move it over. 28:08.840 --> 28:14.480 Then we can move this arcane shards over, and it looks like I've moved it by -200. 28:15.160 --> 28:19.060 And we can see what they look like next to each other. 28:19.060 --> 28:24.040 And then we can ask ourselves, are we okay with our shards ever being that close together? 28:24.070 --> 28:32.470 I'm going to set its location X to zero and its location Y to 200, so I can see what they look like 28:32.470 --> 28:33.670 next to each other this way. 28:33.670 --> 28:40.960 Now, if you're okay with that much of a separation, then you can use that as a ballpark when you position 28:40.960 --> 28:42.820 your points in your point collection. 28:42.820 --> 28:47.950 If you need a little bit more room than that, you can set this at say, 250. 28:48.100 --> 28:52.030 And that way you'll see that they're a little bit more spaced apart. 28:52.480 --> 28:56.680 I think that's probably a better distance. 28:57.130 --> 29:03.430 So with that, I can take these and remove them and go back to my point collection and just make sure 29:03.430 --> 29:10.570 that I move point one at least 250 units away from that central point. 29:10.570 --> 29:18.280 And make sure based on this gauge here, that we don't ever move points much less than 250 units away. 29:19.330 --> 29:21.850 So we'll use this as a kind of metric. 29:22.300 --> 29:24.130 Point one is 250 away. 29:24.160 --> 29:27.160 Now I'm going to position the rest of these. 29:27.160 --> 29:29.980 So first I'm going to take point two. 29:29.980 --> 29:32.410 And I'm going to add a billboard component. 29:33.100 --> 29:38.890 And I'm going to search for target and use the target icon. 29:41.050 --> 29:44.770 From editor materials, and I'm just going to position it. 29:44.770 --> 29:47.740 And I don't even have to use snapping. 29:47.740 --> 29:52.570 I don't even have to go perfectly in one direction or another. 29:52.570 --> 29:56.680 That's part of the strength of having a point collection is we can place these by hand. 29:56.680 --> 29:58.300 So I'm going to place it about there. 29:59.960 --> 30:01.670 And I'll add a billboard. 30:02.750 --> 30:08.270 To point three and change it to use the target icon. 30:10.740 --> 30:16.470 And I'm going to move point three, not the billboard, but point three itself over. 30:17.200 --> 30:18.910 And I'm going to put it right there. 30:18.910 --> 30:19.840 And you know what? 30:19.840 --> 30:21.340 I think I'm going to take two. 30:21.340 --> 30:25.840 And it looks like I moved point two billboard. 30:26.260 --> 30:31.810 So I'm going to actually reset its location and select the billboard itself and move that. 30:31.810 --> 30:34.750 So just something to be aware of. 30:36.700 --> 30:38.470 I'm going to have points. 30:39.120 --> 30:46.650 One through three, evenly spaced out, so that if we spawn these starting at point zero, I'd like 30:46.650 --> 30:49.260 to go out in this kind of manner. 30:50.360 --> 30:56.600 So it doesn't hurt to select those scene components themselves and make sure that they're exactly at 30:56.600 --> 30:58.730 the locations you expect. 30:59.690 --> 31:03.560 We can also go to top mode if we want to see it from this perspective. 31:03.560 --> 31:11.930 And we don't want any sort of optical illusions fooling us into where exactly we think these are. 31:11.960 --> 31:19.670 So now that I have points one through three, I'm going to go ahead and minimize those and start on 31:19.670 --> 31:20.690 point four. 31:20.690 --> 31:22.430 So I'm going to add a billboard to that. 31:22.430 --> 31:28.400 And because the rest of this is going to be repetition, I can time lapse four through ten. 31:28.400 --> 31:31.430 And I'm just going to space these evenly out. 31:31.430 --> 31:38.000 And I'm going to make sure that the lower the number, the closer to the origin of the actor, the closer 31:38.000 --> 31:40.040 to its root component. 31:40.040 --> 31:46.880 And that way as we're spawning these, if we use that order to our advantage, then we can choose locations 31:46.880 --> 31:51.860 closest to the center when we only want to spawn for some of these locations. 31:51.860 --> 31:53.990 So I'm going to time lapse the rest of this. 32:32.650 --> 32:36.190 Okay, so I believe I have all ten points. 32:41.630 --> 32:48.650 And I can just run through each of them and make sure that the closest ones are the lowest in number 32:48.650 --> 32:49.700 for their names. 32:49.700 --> 32:51.470 So there's point one for me. 32:51.470 --> 32:53.600 Point two, here's three. 32:53.630 --> 32:57.020 They're not in order here in the components panel. 32:57.020 --> 32:58.910 So I need to be careful there. 32:58.910 --> 33:00.290 Here's four. 33:00.320 --> 33:01.490 Here's five. 33:01.490 --> 33:03.080 It's out there a little bit. 33:03.080 --> 33:06.980 Here's 678 okay. 33:06.980 --> 33:10.640 So I'm going to go from top to perspective and rotate a bit. 33:10.640 --> 33:12.560 And here's my little point collection. 33:12.560 --> 33:14.900 And of course you could go all out with this. 33:14.900 --> 33:17.000 You can put as many of these as you want. 33:17.000 --> 33:19.310 But at least now I have this point collection. 33:19.310 --> 33:24.770 And the reason I wanted the ability to rotate these is because, well, if I use the same point collection 33:24.770 --> 33:30.980 every time, even if I pick random locations from around inside of it, well, that's going to become 33:30.980 --> 33:34.610 noticeable, but not if you rotate it every time. 33:34.610 --> 33:40.100 So now that I have a point collection and it has points in it, I'm going to go into arcane shards and 33:40.100 --> 33:46.100 I'm going to spawn one of these point collections and just use its points. 33:47.460 --> 33:50.910 So we'll just start by drawing some debug spheres. 33:50.910 --> 33:55.560 Now to spawn this I'm going to use Spawn Actor. 33:56.250 --> 34:01.440 And I can use spawn actor from class and just specify my point collection class. 34:02.580 --> 34:07.200 So if I search for BP point collection, I have a point collection. 34:07.680 --> 34:10.710 Now where do we want the point collection to start? 34:10.710 --> 34:14.250 Well, we know how to get target data under the mouse. 34:14.250 --> 34:16.410 That would be a good start for us. 34:16.410 --> 34:22.380 So what I'm going to do is right click and get target data under mouse. 34:24.710 --> 34:27.080 An on press can be hooked up to this. 34:27.080 --> 34:33.740 And then once we have valid data, then we can go on and spawn an actor, because now our data handle 34:33.740 --> 34:34.970 has that hit result. 34:34.970 --> 34:37.700 We can call get hit results from target data. 34:37.700 --> 34:40.850 And this hit results we can break. 34:42.500 --> 34:46.790 So break hit result and we can get the impact point. 34:47.380 --> 34:48.400 From it. 34:48.400 --> 34:55.780 And if I just hook this up to spawn transform, then this is going to create a transform from the vector. 34:55.780 --> 35:01.780 And if you don't like that, you don't like that you can't see what the rotation and scale are. 35:01.810 --> 35:06.370 You could split the struct pin and you can just plug impact point straight in. 35:06.370 --> 35:08.980 And then you can see for sure what those values are. 35:08.980 --> 35:13.780 Spawn transform, rotation is zero, scale is one, and so on. 35:14.110 --> 35:19.810 Now for the collision handling override I'm just going to use always spawn ignore collisions even though 35:19.810 --> 35:21.010 we shouldn't have any. 35:21.010 --> 35:26.710 This is just a bunch of scene components that really are no collisions to be worried about. 35:27.400 --> 35:33.730 But after we've spawned the actor, now we have a point collection and I'm going to take that point 35:33.730 --> 35:34.630 collection. 35:35.720 --> 35:41.990 And I'm going to call the blueprint pure function, get ground locations or get ground points rather. 35:42.380 --> 35:46.460 And this can take in a location to start with. 35:46.460 --> 35:48.230 That can be our impact point. 35:48.230 --> 35:52.190 I'm just going to drag it on behind that node, even though I don't like doing that. 35:52.490 --> 35:58.010 For now, I'm just going to drag it in there and we know that we can pass in anything up to and including 35:58.010 --> 36:02.300 11, and we can try a your override as well. 36:02.300 --> 36:04.580 But I'm going to try first with zero. 36:04.580 --> 36:09.590 And after getting those ground point locations I'm going to draw some debug spheres. 36:09.590 --> 36:16.130 But it would be a great idea once we spawn this to promote it to a variable so we can delete it later. 36:16.130 --> 36:18.860 So I'm going to call this point collection. 36:19.070 --> 36:23.330 And once we're done with the point collection we can go ahead and destroy it. 36:25.420 --> 36:31.090 So after getting the ground points, how are we going to draw debug spheres? 36:31.090 --> 36:34.660 Well, we can loop over this array we can use for each loop. 36:36.440 --> 36:37.460 We can hook this up. 36:37.460 --> 36:42.920 And for each of these scene components, we can draw a debug sphere. 36:45.270 --> 36:49.470 So in the loop body draw debug sphere. 36:50.120 --> 36:53.900 And I'm going to take each element and get its location. 36:53.900 --> 36:55.790 So get world location. 36:56.360 --> 36:58.220 And that will be the center for the sphere. 36:58.220 --> 37:00.050 The radius can be 20. 37:00.530 --> 37:02.870 We'll leave the line color at white. 37:02.870 --> 37:08.120 The duration can be 20s thickness will leave alone. 37:08.330 --> 37:14.120 And by the time we're done with this for each loop, we can then end our ability by hiding that magic 37:14.120 --> 37:17.600 circle, having a delay, and ending the ability. 37:17.600 --> 37:18.590 And of course. 37:19.350 --> 37:23.100 We can also destroy our point collection. 37:24.650 --> 37:27.650 So we're going to call Destroy actor on it. 37:29.890 --> 37:35.680 And then every time we execute this ability, we're making a new point collection. 37:35.680 --> 37:39.760 And we can even try different your overrides here. 37:39.790 --> 37:42.340 So let's give this a shot. 37:43.090 --> 37:45.220 I'm going to save all and press play. 37:45.220 --> 37:49.450 And I'm going to try pressing the one key. 37:49.960 --> 37:52.180 And then we're now waiting for input. 37:52.180 --> 37:53.680 So I'm going to press it again. 37:54.280 --> 37:56.800 And there we have our points and check it out. 37:56.800 --> 37:58.720 One of these is up on the stairs. 37:58.720 --> 38:02.230 So we're now seeing how useful that line trace can be. 38:03.220 --> 38:04.330 Pretty cool. 38:05.340 --> 38:07.110 So that's looking pretty nice. 38:08.230 --> 38:10.930 So once again I'm going to go ahead and press one. 38:10.930 --> 38:11.950 Press it again. 38:11.950 --> 38:18.580 And we have these points right now I'd like to see what happens if we pass in a yaw override. 38:18.580 --> 38:21.730 First of all I'm just going to pass in a value like 45. 38:21.730 --> 38:24.580 So I expect to see a different set of points. 38:25.000 --> 38:26.860 And to me it does look different. 38:26.860 --> 38:29.230 But it's a little hard to tell. 38:29.230 --> 38:34.660 So one way we can tell is by using a random value. 38:35.550 --> 38:46.920 So random float in range and we can go from say 0 to 360 and we can hook that in and then we can do 38:46.920 --> 38:48.450 this a couple times. 38:48.450 --> 38:51.150 We can show these ground points twice. 38:51.150 --> 38:55.890 So we can place our mouse cursor at one particular location. 38:55.890 --> 38:58.680 I'm going to just come out here so I have more room. 39:00.510 --> 39:03.720 So I'm going to place my mouse cursor at this location here. 39:05.080 --> 39:08.320 Let's full screen and I'm going to press one. 39:10.870 --> 39:12.460 And then press one again. 39:12.820 --> 39:13.870 There's my points. 39:13.870 --> 39:19.540 And now I'm going to keep my mouse at that location, press one and press one again. 39:19.540 --> 39:22.600 And the second time we see new points. 39:22.600 --> 39:27.730 If that your override didn't work, we wouldn't see points just come out of nowhere. 39:27.730 --> 39:31.210 These spheres would all be drawn on top of each other. 39:31.210 --> 39:35.500 So that tells us that we're rotating these points. 39:37.650 --> 39:38.520 So this is great. 39:38.520 --> 39:42.900 Now we have some points and we can use this point collection. 39:42.900 --> 39:46.680 And of course we can always adjust these points. 39:46.980 --> 39:51.240 I may not have the most even distribution here of my points. 39:51.240 --> 39:58.740 So it might be worthwhile for me to go through and just kind of maybe spread them out a little bit or 39:58.740 --> 40:03.270 make sure that they're not quite so elongated as they are. 40:07.120 --> 40:14.020 But the cool thing is that we have these points and we have the ability to get some random rotation 40:14.020 --> 40:14.800 as well. 40:17.000 --> 40:22.430 So that's the next step in our ability is being able to get some random points. 40:22.430 --> 40:23.540 And. 40:24.400 --> 40:25.960 That's looking pretty good. 40:27.020 --> 40:33.800 Now these are random points, but if you're observant, you're going to notice something. 40:34.370 --> 40:38.600 If I press play and I create my random point cloud. 40:38.990 --> 40:40.760 Well, here's what it looks like. 40:40.760 --> 40:42.710 And if I go ahead and eject. 40:44.380 --> 40:49.000 And I take a good look from the top here, and then I go into my point collection. 40:49.570 --> 40:51.310 There's something wrong. 40:51.310 --> 40:55.720 This collection of points looks nothing like this collection of points. 40:55.720 --> 41:00.730 Even though we gave a random rotation, the rotation should be consistent. 41:00.730 --> 41:04.630 It should be like taking the whole actor and rotating it by a certain amount. 41:04.630 --> 41:12.280 But this looks seemingly like a bunch of random points that have all been rotated randomly individually. 41:12.280 --> 41:17.170 And that's exactly what is happening, because these are blueprint pure nodes. 41:18.240 --> 41:25.620 You see, every time we use a blueprint pure node, it's going to be evaluated again, especially with 41:25.620 --> 41:28.050 these random number generator functions. 41:28.050 --> 41:35.130 If the wire that's using it's output is used for anything, then the blueprint pure function is called 41:35.130 --> 41:35.640 again. 41:35.640 --> 41:39.150 And that includes using them in for loops. 41:39.150 --> 41:46.710 For example, in our for each loop this get ground points that returns an array is returning a new array 41:46.710 --> 41:51.090 every single time because it itself is a blueprint pure function. 41:51.090 --> 41:55.440 So for that reason we have to be careful with these blueprint pure functions. 41:55.440 --> 41:57.630 For one, they're expensive. 41:57.630 --> 42:03.000 If you use a for loop with a blueprint pure function, especially one that does some array business, 42:03.000 --> 42:05.790 and for two they can be confusing. 42:05.790 --> 42:13.440 Now I'm going to set the get ground points num points input to four and just show you really what I 42:13.440 --> 42:13.830 mean. 42:13.830 --> 42:18.960 It's easier to tell this kind of thing when we have a smaller number of points. 42:18.960 --> 42:23.010 So the points number of points is four I'm going to press one. 42:23.010 --> 42:24.060 Press one again. 42:24.060 --> 42:25.050 Now look at that. 42:25.050 --> 42:27.870 This doesn't really look like the first four points. 42:27.870 --> 42:31.590 Not if we go in and take a look at point zero here in the middle. 42:31.620 --> 42:33.840 Point one here right there. 42:33.840 --> 42:35.460 Point two is right here. 42:35.460 --> 42:36.930 So we have this triangle. 42:36.930 --> 42:39.690 And then point three is right here. 42:39.690 --> 42:44.100 So we basically have one big triangle and one point in the center. 42:44.100 --> 42:45.300 That's the origin. 42:45.300 --> 42:49.140 That's what we should see if we didn't have any random rotation. 42:49.140 --> 42:55.080 If the yaw override was zero then if we go in and press one and press one again, that's what it should 42:55.080 --> 42:57.660 look like a big triangle, one in the middle. 42:58.510 --> 43:04.780 And if we were rotating everything consistently, then that whole triangle would then be rotated right. 43:06.110 --> 43:14.330 So the way to fix this is to promote this array returned from ground points to a variable. 43:14.330 --> 43:17.420 So we go ahead and promote to variable. 43:17.420 --> 43:20.240 And we can call this ground points. 43:22.860 --> 43:26.430 And once we do that, now we have a variable. 43:26.430 --> 43:32.850 And if we use that instead in our array, we're not evaluating a blueprint pure function multiple times. 43:32.850 --> 43:36.480 We can just evaluate it once and cache off that data. 43:36.480 --> 43:43.140 So if I hook this random float back in, now that we're using this ground points array, instead of 43:43.140 --> 43:48.060 evaluating the blueprint pure node every time, let's see how that ends up. 43:48.640 --> 43:50.500 So I'm going to press one and one. 43:50.500 --> 43:52.870 And we have our familiar triangle. 43:52.870 --> 43:54.160 It's not all muddled up. 43:54.160 --> 43:58.450 And if I press it again we have the same triangle but it's rotated. 43:59.280 --> 44:06.450 And I can do this multiple times, and I see that each new set of points is just three new points, 44:06.480 --> 44:09.660 a triangle with one point in the middle. 44:10.140 --> 44:14.220 And that's exactly the behavior that I was expecting and wanting. 44:14.220 --> 44:21.750 So now that we have this function that gives us a collection of points that's rotated, we can trust 44:21.750 --> 44:24.510 it when we increase that number of points there. 44:26.930 --> 44:32.900 Okay, so with that we now have a point collection. 44:32.930 --> 44:34.430 It has points in it. 44:34.430 --> 44:36.770 We can rotate the point collection. 44:36.770 --> 44:38.870 We can get any number of points. 44:38.870 --> 44:43.280 Well not any number but up to 11 because that's how many points we have in here. 44:43.280 --> 44:49.490 And we can generate a bunch of random points and we can specify how many we want. 44:49.490 --> 44:53.000 And if we only want one, we should get that central point. 44:55.760 --> 44:57.320 So right there in the middle. 44:58.240 --> 45:03.190 And with our ability at level one, that's where we're going to spawn that first shard. 45:03.190 --> 45:07.390 But then when we level up our ability, we're going to pass in higher numbers. 45:07.390 --> 45:10.960 So at level two I'd like to spawn two shards. 45:11.710 --> 45:15.820 And it's going to look like this one at the center and one slightly far out of it. 45:15.820 --> 45:22.960 But we're getting a random rotation every time, so that way it doesn't look the same every single time. 45:22.960 --> 45:26.530 And then when our ability levels up to level three. 45:27.300 --> 45:28.920 Will spawn three of them. 45:30.230 --> 45:32.780 And it'll be a little triangle like this. 45:34.610 --> 45:36.590 And of course, at level four. 45:38.060 --> 45:43.190 Then it'll look more like this, where we have one in the middle and three and so on. 45:43.190 --> 45:44.000 You get the point. 45:44.030 --> 45:48.830 Now these are spaced a little bit too far apart, so I'm going to just bring them in. 45:48.830 --> 45:50.750 I'm going to time lapse bringing them in. 45:50.750 --> 45:52.760 And then we're going to wrap up this video. 46:05.750 --> 46:06.290 Okay. 46:06.290 --> 46:10.310 And with that, I'm just going to pass in 11 and see the spread here. 46:11.050 --> 46:12.370 And that looks pretty good. 46:13.140 --> 46:13.740 Okay. 46:13.740 --> 46:20.340 So now we have random locations and they're evenly spread out. 46:20.340 --> 46:25.590 So if we had just picked random locations with random number generators for each location, we could 46:25.590 --> 46:28.140 have shards overlapping with each other. 46:28.140 --> 46:33.930 So another benefit of this is we have evenly distributed points randomly selected. 46:33.930 --> 46:40.620 So in the next video we're going to start going about how we can actually spawn those shards and make 46:40.620 --> 46:42.120 this actually look really cool. 46:42.120 --> 46:44.940 So excellent job and I'll see you soon.