WEBVTT 00:06.840 --> 00:08.040 Welcome back. 00:08.070 --> 00:14.280 So now that we have visuals looking pretty good for our Arcane Shards ability, it's time to start thinking 00:14.280 --> 00:15.480 about damage. 00:15.660 --> 00:17.250 Now for Arcane Shards. 00:17.250 --> 00:19.410 I'd like to have radial damage. 00:19.410 --> 00:21.420 I'd like to be able to cast this. 00:21.420 --> 00:24.960 And for each of these shards, I'd like to cause more damage. 00:24.960 --> 00:31.590 The closer my enemies are to those individual shards, and they'll take a little bit of damage as their 00:31.590 --> 00:34.380 distance increases to those shards. 00:34.380 --> 00:37.230 So radial damage with a falloff. 00:37.230 --> 00:43.890 And if we're going to be implementing damage that has a falloff, we're going to need some parameters. 00:44.160 --> 00:47.760 Now I'd like to take a look at one engine function. 00:47.760 --> 00:55.380 If I double shift to search I'm going to search for radial damage with falloff. 00:57.210 --> 00:59.400 And we have a gameplay statics function. 00:59.400 --> 01:02.040 Apply radial damage with falloff. 01:02.890 --> 01:05.680 Now this is an interesting function. 01:05.680 --> 01:09.640 In fact, Unreal Engines damage system itself is quite interesting. 01:09.640 --> 01:16.810 It has damage capabilities, but it doesn't really have a built in concept of health. 01:16.810 --> 01:22.720 You're supposed to do with these damage functions what you need for your project. 01:22.720 --> 01:31.630 So apply radial damage with falloff is just going to perform this algorithm where it actually sees which 01:31.630 --> 01:33.700 actors are overlapping with it. 01:33.700 --> 01:40.360 And for any actors overlapping with it, it's going to if we scroll down to the bottom called Take Damage 01:40.360 --> 01:40.900 on it. 01:40.900 --> 01:50.080 So it calculates the falloff using its own algorithm, it performs the sphere query, similar to what 01:50.080 --> 01:53.560 we've done in one of our functions and our function library. 01:53.560 --> 01:55.540 And then it ends up calling take damage. 01:55.540 --> 02:02.170 And take damage is a function that is virtual and can be overridden in any actor. 02:02.170 --> 02:10.120 And so it's up to us to receive that value passed through for the damage calculated and take damage. 02:10.120 --> 02:10.930 So apply. 02:10.930 --> 02:13.780 Radial damage with falloff is something we can use. 02:13.780 --> 02:21.220 We can take advantage of the built in engine capabilities, and then we can choose how to handle that 02:21.220 --> 02:21.670 damage. 02:21.670 --> 02:25.630 But apply radial damage with falloff requires some parameters. 02:25.630 --> 02:31.660 It takes in a base damage amount, and it basically nerfs that damage depending on how far away the 02:31.660 --> 02:39.790 target is from some origin, and it uses two spheres, a minimum and a maximum sphere. 02:39.790 --> 02:45.610 One sphere has an inner radius, one sphere has an outer radius, and any actors that are within that 02:45.610 --> 02:53.620 inner radius get the full amount of damage, that base damage passed in, and any actors that are outside 02:53.620 --> 03:00.730 of damage outer radius, they get the minimum amount of damage passed in, and then any actors in between 03:00.730 --> 03:08.260 those two radii have base damage with some falloff, some percentage taken off of that damage depending 03:08.260 --> 03:10.420 on the falloff chosen. 03:10.420 --> 03:12.280 And there are different types of falloff. 03:12.280 --> 03:19.000 There's linear fall offs, other types of fall offs that are smoother curves, such as cubic mathematics 03:19.000 --> 03:19.930 functions. 03:19.930 --> 03:25.240 And if you want the details, you can always look at the implementation here in this function to see 03:25.240 --> 03:29.350 exactly how that radial damage is calculated. 03:29.710 --> 03:33.940 But if we're going to call this function we need some of these parameters. 03:33.940 --> 03:36.910 Notice there's a damage falloff parameter. 03:36.910 --> 03:42.970 And if we look at how that's used we see that it's passed into radial damage params. 03:46.810 --> 03:52.870 If we go to this, we see that it has these base damage, minimum damage, these parameters. 03:52.870 --> 03:53.650 Right. 03:53.920 --> 03:59.680 And it also has get damage scale, which returns the damage done at a certain distance. 03:59.680 --> 04:02.110 This is defined in damage events. 04:04.530 --> 04:08.400 If we look for jet damage scale, it has a distance from epicenter. 04:09.390 --> 04:11.550 And it checks the damage fall off here. 04:11.550 --> 04:18.600 Sees if it's equal to zero, then it says no fall off or inside an a radius means full effect. 04:18.990 --> 04:20.280 It returns one. 04:20.280 --> 04:21.750 This is a scale by the way. 04:21.750 --> 04:24.090 So we're scaling damage by this. 04:24.090 --> 04:27.450 But notice here it's calculating an interpolated scale. 04:27.450 --> 04:31.770 It's creating a damage scale set to one minus some value. 04:31.770 --> 04:33.240 This is a ratio. 04:33.240 --> 04:37.380 It's the validated distance minus validated distance inner radius. 04:37.380 --> 04:44.760 So the space in between the inner radius and this distance divided by the validated outer radius minus 04:44.760 --> 04:46.080 validated inner radius. 04:46.080 --> 04:48.360 So it's scaling outer radius. 04:48.360 --> 04:54.390 So it's setting damage scale equal to one minus this ratio here which means damage scale is going to 04:54.390 --> 04:56.370 probably be less than one. 04:56.580 --> 05:00.510 And then it takes that damage scale and it calls power on it. 05:00.510 --> 05:05.400 It takes damage scale and raises it to the power of the damage fall off. 05:05.400 --> 05:10.260 So we're taking a value that's either one or smaller. 05:10.260 --> 05:14.010 So smaller than one say 0.25 for example. 05:14.010 --> 05:15.750 And we're raising it to a power. 05:15.750 --> 05:20.610 And if that power is smaller than one then damage scale is going to get smaller. 05:20.610 --> 05:21.630 I mean, think about it. 05:21.630 --> 05:23.940 Let's say damage scale is 0.25. 05:24.180 --> 05:26.640 And let's say damage fall off is two. 05:26.670 --> 05:29.280 Well, 0.25 times 0.25. 05:29.310 --> 05:32.340 That's a quarter of a quarter, right? 05:32.340 --> 05:35.550 If it was 0.5 then that would be half of a half. 05:35.550 --> 05:36.660 What's half of a half? 05:36.660 --> 05:37.410 That's a quarter. 05:37.410 --> 05:43.770 So raising a value that's less than one to a power that's greater than one is going to make it smaller. 05:43.770 --> 05:50.670 So if we just want to have this linear fall off, we can just have a damage fall off of one. 05:50.670 --> 05:55.110 Otherwise if we want a harsher fall off we can use a higher value for damage fall off. 05:55.110 --> 05:57.090 So that's how damage fall off works. 05:57.090 --> 06:04.980 And now we understand that if we're going to be using our built in apply radial damage with fall off 06:04.980 --> 06:08.250 and responding to it, then we're going to need some parameters. 06:08.250 --> 06:15.630 Those parameters are going to be a radial damage minimum, a radial damage origin, a radial damage 06:15.630 --> 06:19.320 inner and outer radius, a fall off if we want that. 06:19.320 --> 06:21.480 Otherwise we can hard code one. 06:21.480 --> 06:25.920 And then we have a bunch of other things, such as a damage type class. 06:25.920 --> 06:32.040 Now we're using gameplay tags to identify our damage types, but damage types are essentially classes 06:32.040 --> 06:36.150 that you only add static functions to if you add anything to them. 06:36.150 --> 06:40.080 Because we never instantiate instances of them, we just use the class. 06:40.080 --> 06:44.820 So you can use it as a static class, like an identifier, and add static functions. 06:44.820 --> 06:48.960 If you want, you could subclass this and give it a gameplay tag. 06:48.960 --> 06:53.010 I don't think we really have any uses for it in this project. 06:53.010 --> 06:58.680 And of course we have a damage prevention channel if you want to prevent damage for any specific channel. 06:58.680 --> 07:03.720 So we're going to create some radial damage parameters. 07:03.720 --> 07:06.870 And I'd like to add those to a couple of our types. 07:06.870 --> 07:08.640 I'm going to go to our ability types. 07:08.640 --> 07:10.200 We have CP here. 07:10.200 --> 07:12.180 And I'll open the header file. 07:12.180 --> 07:15.720 And we have f damage effect params. 07:15.720 --> 07:19.050 I'd like to add some parameters for radial damage here. 07:19.050 --> 07:21.300 And we also have the effect context. 07:21.300 --> 07:27.090 And this will be a good way for us to carry radial damage params with us throughout the pipeline if 07:27.090 --> 07:31.200 we want to access it, say in exec calc damage. 07:31.560 --> 07:33.840 So that's what I'd like to do in this video. 07:33.840 --> 07:39.630 I'd like to create some radial damage parameters, and we're going to start by adding them to f damage 07:39.630 --> 07:40.830 effect params. 07:41.160 --> 07:45.690 So down here at the bottom I'm going to add a few parameters. 07:45.690 --> 07:50.490 One will be a boolean and I'm going to call this b is radial damage. 07:50.520 --> 07:52.320 And it'll be false by default. 07:52.320 --> 07:56.280 So if we never set it then we'll never have radial damage. 07:56.280 --> 08:02.310 And I'll make it blueprint red right now in addition to this boolean that we can check to see if we 08:02.310 --> 08:07.410 even have radial damage, we can have a few radial damage parameters. 08:07.770 --> 08:10.440 We're going to have a float. 08:10.440 --> 08:15.210 And this can be our radial damage inner radius. 08:16.350 --> 08:24.150 We can have a float radial damage outer radius, and we can initialize these both to zero. 08:31.290 --> 08:35.490 And we can also have a radial damage origin, which can be an f vector. 08:35.490 --> 08:37.500 So we'll make an f vector. 08:37.500 --> 08:39.900 Radial damage origin. 08:42.180 --> 08:45.030 We'll initialize it to the zero vector. 08:49.940 --> 08:52.940 And with that, we should have enough information. 08:53.390 --> 08:59.750 Now, if we really wanted to, we could have a radial damage minimum amount, and that could be separate 08:59.750 --> 09:02.660 from our base damage that we have here. 09:02.660 --> 09:07.550 But I'm just going to use zero for my minimum radial damage. 09:07.550 --> 09:10.460 And with that let's add blueprint read. 09:10.460 --> 09:15.110 Write to all of these in case we want to set them from within. 09:15.110 --> 09:15.680 Blueprint. 09:15.680 --> 09:23.900 If we make one of these structs now that we have these for radial damage properties, we're going to 09:23.900 --> 09:30.560 want to make sure that we're setting these in our damage effect params when we make them with our gameplay 09:30.560 --> 09:33.440 ability, or a damage gameplay ability. 09:33.770 --> 09:38.210 And that means or a damage gameplay ability should have the option to be radial. 09:38.240 --> 09:43.730 You see, we want radial damage for arcane shards, but for that reason I want our whole system to be 09:43.730 --> 09:45.710 capable of radial damage. 09:45.710 --> 09:50.270 And that way when we have another radial damage spell, we don't have to reinvent the wheel. 09:50.570 --> 09:53.090 So I'm going to go into aura damage gameplay ability. 09:53.120 --> 09:54.620 Here's the cpp file. 09:54.620 --> 09:56.480 I'm going to go into the header as well. 09:58.430 --> 10:01.760 And we're going to add some radial damage parameters. 10:01.760 --> 10:07.550 And they're going to be identical to our damage effect parameters, namely these four here. 10:07.550 --> 10:09.290 So I'm just going to copy them. 10:09.290 --> 10:13.730 And over here in aura damage gameplay ability I'm going to go ahead and paste them. 10:13.730 --> 10:17.930 The only difference is I'm only going to make them edit defaults only. 10:17.930 --> 10:19.880 We don't need them to be blueprint read write. 10:19.880 --> 10:22.190 So I'm going to change their U properties. 10:24.880 --> 10:31.690 Now I'm going to take these four and set them in our aura damaged gameplay ability function make damage 10:31.690 --> 10:33.940 effect params from class defaults. 10:33.940 --> 10:40.270 We're going to go ahead and set these, but really only if this is radial damage. 10:40.270 --> 10:44.860 So we're going to first check if B is radial damage. 10:44.860 --> 10:49.240 If that's true then we can go ahead and set the radial damage parameters. 10:49.240 --> 10:50.860 We're going to say params. 10:51.970 --> 10:57.220 Dot b is radial damage equals B is radial damage. 10:57.220 --> 10:58.750 We'll carry that across. 10:58.750 --> 11:02.680 We'll have params dot radial damage origin. 11:02.680 --> 11:08.590 We'll set that to radial damage origin and two more params dot radial damage inner radius. 11:09.100 --> 11:15.400 We'll set that to radial damage inner radius and params dot radial damage outer radius. 11:15.400 --> 11:18.280 We'll set that to radial damage outer radius. 11:18.790 --> 11:25.510 And now our function for making these params sets them based on the ability class itself. 11:25.510 --> 11:30.310 And then we can carry those along whenever we need to apply a gameplay effect. 11:31.210 --> 11:36.910 Now, if we're going to apply a gameplay effect and make use of these, we need to decide how. 11:37.300 --> 11:40.060 I'd like to set them in the effect context. 11:40.060 --> 11:46.180 And that way we can check the effect context to see if it's radial damage at any point in our damage 11:46.180 --> 11:47.050 pipeline. 11:47.470 --> 11:53.920 Another alternative is to make these set by color magnitudes, but I'm opting for setting them in the 11:53.920 --> 11:55.420 effect context. 11:55.420 --> 12:01.390 And that way we don't have to crowd up our gameplay effect spec with too many set by color magnitudes, 12:01.390 --> 12:05.650 and we don't have to create too many gameplay tags just for those reasons. 12:06.010 --> 12:12.850 So I'm going to go back to aura ability types, and we're going to add these into our gameplay effect 12:12.850 --> 12:14.110 context. 12:14.840 --> 12:17.300 So we're going to have four new variables here. 12:17.300 --> 12:23.960 Which means we're going to have a few steps including determining how these should be serialized. 12:24.530 --> 12:29.330 So just after knockback force we're going to add these four variables. 12:29.330 --> 12:37.130 And if I'd like to be lazy I could go back to aura damage gameplay ability or just scroll up to. 12:38.500 --> 12:41.920 F damage effect params and I can just copy them from here. 12:41.950 --> 12:45.970 Starting it is radial damage so I'm going to do that. 12:46.610 --> 12:48.440 And I'm going to paste them down here. 12:48.440 --> 12:51.110 Only they're not going to be blueprint read write. 12:51.110 --> 12:53.090 They're just going to be you properties. 12:53.450 --> 12:57.740 So now we have a new bool two floats and an F vector. 12:57.740 --> 12:59.900 And they're all initialized. 13:00.260 --> 13:07.250 So because these are protected we're going to need getters and setters for each of them starting with 13:07.250 --> 13:09.950 the Boolean and working our way down. 13:10.280 --> 13:12.650 So I'm just going to add the getter here. 13:13.010 --> 13:22.670 It's going to be bool is radial damage const return B is radial damage. 13:23.580 --> 13:26.160 And while I'm at it, I'll make this better as well. 13:26.190 --> 13:40.740 Void set is radial damage, takes a bool, be in is radial damage, and sets B is radial damage to be 13:40.740 --> 13:42.690 in is radial damage. 13:42.990 --> 13:45.390 So this is a bit monotonous. 13:45.390 --> 13:50.310 So I can time lapse creating the getters and setters for the remaining three. 13:50.310 --> 13:51.720 So let's do that. 14:31.990 --> 14:32.620 All right. 14:32.620 --> 14:34.660 So I have my getters and my setters. 14:34.660 --> 14:39.160 Now the next step is to net serialize these. 14:39.160 --> 14:42.460 Now I'm going to go into our ability types Datcp. 14:42.670 --> 14:47.530 And we're going to flip our bits by checking our member variables. 14:47.530 --> 14:52.600 Now the first one I'm going to check here is is radial damage. 14:52.600 --> 14:59.950 So I'm going to say if B is radial damage then I'm going to flip the 16th bit. 15:00.700 --> 15:04.240 And I'm not going to bother flipping any of the other bits. 15:04.240 --> 15:06.640 If is radial damage is false. 15:06.640 --> 15:14.260 So we're going to check not only are these zero or the zero vector, but we're also going to check is 15:14.260 --> 15:16.120 radial damage as well. 15:17.300 --> 15:18.170 We can do that. 15:18.170 --> 15:20.000 We can also just check them here. 15:20.000 --> 15:22.100 Inside of B is radial damage. 15:22.100 --> 15:29.990 If we wanted to do that, we could say if radial damage inner radius is greater than zero. 15:32.570 --> 15:35.450 In that case, we can flip the 17th bit. 15:36.940 --> 15:39.610 We can also check the outer radius. 15:40.970 --> 15:43.010 So we could change this to outer. 15:45.400 --> 15:55.450 And flip the 18th bit, and then we can finally check if radial damage origin dot is zero and we can 15:55.450 --> 15:56.650 put a knot here. 15:56.650 --> 16:02.200 So if it's not zero then we'll flip the 19th bit just like that. 16:02.200 --> 16:07.330 Now if you don't like nesting them, if it seems a little bit confusing, you could take these out and 16:07.330 --> 16:14.050 just check both these conditions and have an end and check B is radial damage. 16:14.050 --> 16:15.460 You could do it that way too. 16:15.460 --> 16:21.670 So with that we can now serialize and we need serialized bits to accommodate now for 19 bits. 16:21.670 --> 16:24.100 So we're going to pass a 19 into that. 16:25.680 --> 16:32.940 And after that we can check these new bits 16, 17, 18 and 19. 16:32.970 --> 16:35.640 So let's go all the way down and check those. 16:36.440 --> 16:41.240 So first we're going to check if rep bits. 16:41.570 --> 16:44.450 We're going to use and bitwise and that is. 16:45.260 --> 16:47.510 One left shift 16. 16:49.570 --> 16:59.290 And while I'm at it, I'm just going to copy this before I put anything in there and check 17, 18 and 16:59.290 --> 17:00.160 19. 17:01.180 --> 17:05.320 So if we flipped 16, we can go back up and look. 17:05.320 --> 17:06.670 That's going to be. 17:07.520 --> 17:09.440 For is radial damage. 17:10.160 --> 17:14.330 So what we'll do is we'll take the archive. 17:15.400 --> 17:18.400 And will archive be is radial damage. 17:19.870 --> 17:24.580 Now, if this bit has not been flipped, there's no point in checking these other four. 17:24.610 --> 17:29.590 So if you wanted to, you could also put these inside here as well. 17:30.200 --> 17:38.090 Now we can check if rep bits has its 17th bit flipped and the 17th bit, if we remind ourselves up here 17:38.090 --> 17:40.250 is radial damage inner radius. 17:40.250 --> 17:42.410 So we can archive that float. 17:44.140 --> 17:48.580 So we'll say are radial damage inner radius. 17:49.440 --> 17:52.320 And 18 is the outer radius. 17:52.320 --> 17:54.630 So are radial damage. 17:54.630 --> 17:56.040 Outer radius. 17:56.400 --> 17:58.980 And now for the origin which is an f vector. 17:58.980 --> 18:01.710 So how are we going to handle the f vector. 18:01.740 --> 18:03.510 Well we've seen that we can handle. 18:03.510 --> 18:07.470 Net serialize for f vectors using the f vector. 18:07.470 --> 18:08.460 Net serialize. 18:08.460 --> 18:14.430 So we're going to do that with our radial damage origin. 18:14.430 --> 18:15.180 We're going to call. 18:15.180 --> 18:16.410 Net serialize. 18:16.410 --> 18:18.720 And we're going to pass in the archive. 18:18.720 --> 18:21.240 We're going to pass in the map and be out. 18:21.240 --> 18:22.050 Success. 18:22.810 --> 18:27.340 And with that, we're serializing our radial damage parameters. 18:28.070 --> 18:30.530 Okay, so that's a good start. 18:30.530 --> 18:37.970 We now know that our effect context can accommodate for radial damage parameters, as well as our f 18:37.970 --> 18:40.280 damage effect parameters as well. 18:40.280 --> 18:44.660 And our damage gameplay ability now has radial parameters. 18:44.660 --> 18:47.330 And we'll just set that B is radial damage. 18:47.330 --> 18:49.250 It's set to false by default. 18:49.250 --> 18:52.910 And if we never set it to true then the context doesn't carry it along. 18:52.910 --> 18:55.520 It doesn't even serialize it for replication. 18:55.520 --> 19:03.020 So we're not picking up any bandwidth across the net if we're not using these parameters. 19:03.020 --> 19:05.270 And if B is radial, damage is false. 19:05.270 --> 19:07.610 We don't serialize any of these four. 19:07.610 --> 19:10.460 So that's a nice optimization. 19:11.080 --> 19:14.410 So with that we can go ahead and compile. 19:14.410 --> 19:16.060 Looks like I have the editor open. 19:16.060 --> 19:18.520 I'm going to close it and just compile. 19:18.520 --> 19:20.290 Make sure I have no errors. 19:21.620 --> 19:27.950 And with that, we're now set up and ready to use our radial damage parameters. 19:27.950 --> 19:29.270 And we'll do that next.