1 00:00:03,760 --> 00:00:04,110 Oh cool. 2 00:00:04,150 --> 00:00:09,880 Gameplay is now pretty much there, but our game still feels a little bit dull because our enemies and 3 00:00:09,880 --> 00:00:14,360 our player ship just disappear and blink out of existence whenever they get destroyed. 4 00:00:14,380 --> 00:00:18,460 So in this lecture, let's add some explosions with some particle effects. 5 00:00:18,790 --> 00:00:23,620 Now, whenever I'm working with the particle system, I do like to have some kind of reference to work 6 00:00:23,620 --> 00:00:29,230 from be that from looking at other games or past projects or even just drawing something down on paper. 7 00:00:29,470 --> 00:00:35,050 Now, you don't have to follow exactly what I'm doing in this lecture, so feel free to make this explosion 8 00:00:35,050 --> 00:00:36,430 entirely your own. 9 00:00:36,430 --> 00:00:41,050 And rather than setting a challenge for this lecture, I encourage you to pause the video frequently 10 00:00:41,050 --> 00:00:45,940 to play around with this effect rather than just copying the numbers that I'm going to be using. 11 00:00:45,940 --> 00:00:50,470 Now, the first step to creating our particle system is to add it to the hierarchy. 12 00:00:50,470 --> 00:00:56,230 So in our hierarchy, let's right click, go down to effect, and then add a new particle system. 13 00:00:56,470 --> 00:00:59,800 And this currently looks nothing like our end result. 14 00:00:59,800 --> 00:01:05,050 And the first biggest thing that I'm noticing is that we're currently spitting out these fuzzy particle 15 00:01:05,050 --> 00:01:11,440 balls rather than our nice star shaped particles and the changes we need to look at changing the particles 16 00:01:11,440 --> 00:01:12,520 material. 17 00:01:12,790 --> 00:01:16,930 We haven't created this material yet, so let's go ahead and do that first. 18 00:01:16,930 --> 00:01:23,110 If we head into our asset packs and then space shooter, I've imported this explosion styles sprite 19 00:01:23,110 --> 00:01:23,800 sheet. 20 00:01:23,830 --> 00:01:29,080 If you want to follow along and use the same material as me, then this is attached as a resource to 21 00:01:29,080 --> 00:01:29,590 this lecture. 22 00:01:29,590 --> 00:01:31,750 So go ahead and download and import that. 23 00:01:31,750 --> 00:01:37,900 Now once you've got a spreadsheet you want to use, the next step is going to be to make it into a material 24 00:01:37,900 --> 00:01:39,730 that we can apply to our particles. 25 00:01:39,730 --> 00:01:43,030 And we haven't really dealt with materials too much so far. 26 00:01:43,030 --> 00:01:49,420 So to create one, let's right click in our assets folder, go up to create and then down to material. 27 00:01:49,420 --> 00:01:53,230 Let's call this material M underscore explosion. 28 00:01:53,680 --> 00:01:58,840 And whenever we create a material, it will have a shader which tells the unity how to render it. 29 00:01:58,840 --> 00:02:04,180 If we look up in the inspector, we can see under the shader dropdown that these come in as standard 30 00:02:04,180 --> 00:02:04,960 by default. 31 00:02:04,960 --> 00:02:08,289 But since this is a particle system, we're going to want to change this. 32 00:02:08,289 --> 00:02:15,190 So if we click on our dropdown, head down to particles and we're going to use the standard unlit shader 33 00:02:15,550 --> 00:02:21,640 next, we're going to want to change the render mode from opaque down to additive, and that will just 34 00:02:21,640 --> 00:02:24,640 make the particles appear correctly when we start using them. 35 00:02:24,820 --> 00:02:28,870 And now we need to attach our sprite sheet to this material. 36 00:02:28,870 --> 00:02:33,910 So let's grab our sprite sheet and drag it into the little box next to Albedo. 37 00:02:33,910 --> 00:02:38,260 Under the maps, our material is now set up for what we need. 38 00:02:38,260 --> 00:02:41,290 So let's now go into our political system itself. 39 00:02:41,290 --> 00:02:44,290 Scroll right the way to the bottom under renderer. 40 00:02:45,000 --> 00:02:48,720 And we can drag our new material into the material slot. 41 00:02:49,050 --> 00:02:54,390 We can see that this has now changed our particles to be our sprite sheet, but we don't want the entire 42 00:02:54,390 --> 00:02:55,250 sprite sheet here. 43 00:02:55,260 --> 00:03:00,540 We just want to loop through each individual cell within that sprite sheet and we can do that with some 44 00:03:00,540 --> 00:03:02,370 texture sheet animations. 45 00:03:02,370 --> 00:03:05,130 So let's enable our texture sheet animation. 46 00:03:05,400 --> 00:03:09,210 And if we open this up, we're going to keep the mode as grid. 47 00:03:09,240 --> 00:03:16,140 And for the tiles, we're going to set this to three by one because our sprite sheet is three wide and 48 00:03:16,140 --> 00:03:17,070 one tall. 49 00:03:17,760 --> 00:03:22,380 The changing is quite slow though, so let's bump up our cycles to maybe two. 50 00:03:22,380 --> 00:03:27,300 So this one I'll loop through the sprite sheet twice and rather than always starting on exactly the 51 00:03:27,300 --> 00:03:32,960 same particle, what I'm going to do is I'm going to select a random one to start with in the dropdown, 52 00:03:32,970 --> 00:03:38,100 let's pick a random between two constants and start to anywhere from the first to the third. 53 00:03:38,100 --> 00:03:39,840 So between zero and two. 54 00:03:39,900 --> 00:03:44,190 And now we can see we're getting a little bit more variation with that set. 55 00:03:44,190 --> 00:03:49,380 The next thing I want to do is to amend the colors because they're all white for their entire lifetime 56 00:03:49,380 --> 00:03:52,110 and it's not very fiery or exclusionary. 57 00:03:52,110 --> 00:03:56,790 So let's go up to color over lifetime and then open up our color picker. 58 00:03:56,790 --> 00:04:02,370 And I've actually already got a nice explosion type effect that I like to use, but you can go ahead 59 00:04:02,370 --> 00:04:04,620 and create whatever kind of explosion you like. 60 00:04:04,620 --> 00:04:10,380 You might have purple explosions or green explosions or really anything that you want to show you how 61 00:04:10,380 --> 00:04:11,640 this one is set up. 62 00:04:11,640 --> 00:04:17,070 Along the top, we have various levels of alpha and this will decrease the alpha over time as it goes 63 00:04:17,070 --> 00:04:22,620 through its fire and smoke cycles until eventually petering out entirely along the colors. 64 00:04:22,620 --> 00:04:28,590 We start off with a nice hot yellow color before we go into oranges, orange reds, and then we go into 65 00:04:28,590 --> 00:04:30,570 a reddish gray color for our smoke. 66 00:04:30,840 --> 00:04:36,240 This is now starting to look a bit more like fire, but it's very much the wrong shape and going in 67 00:04:36,240 --> 00:04:37,380 the wrong direction. 68 00:04:37,380 --> 00:04:39,870 So let's look at our shape next. 69 00:04:40,380 --> 00:04:45,480 It's currently set up to be a cone, but we want it to explode out in a circle. 70 00:04:45,480 --> 00:04:48,270 So for our shape, let's click on circle. 71 00:04:48,270 --> 00:04:50,850 And this doesn't really do what we want. 72 00:04:50,880 --> 00:04:54,540 It's now spreading out on a line, but this is a circle. 73 00:04:54,540 --> 00:04:58,830 It's just being rendered in three D and the rotation is incorrect. 74 00:04:58,830 --> 00:05:04,860 So at the very top of our political system, let's zero out the rotation and now we have it generating 75 00:05:04,860 --> 00:05:05,760 in a circle. 76 00:05:05,760 --> 00:05:10,830 While we're here, let's also zero out the transform because that really should be zeroed if we're going 77 00:05:10,830 --> 00:05:12,420 to prefab this later on. 78 00:05:12,450 --> 00:05:18,510 Next, let's try and constrain this explosion so it doesn't spread out quite so far for this. 79 00:05:18,510 --> 00:05:24,420 The first thing I want to do is change the start lifetime and explosions are quite quick, so let's 80 00:05:24,420 --> 00:05:32,130 do a random between two constants and have our particles die out between 0.1 and 0.5. 81 00:05:32,130 --> 00:05:37,200 And with that small change, we can now get a better sense of that hot fire from the explosion and then 82 00:05:37,200 --> 00:05:38,760 the smoke spreading out. 83 00:05:38,850 --> 00:05:41,970 Our particles are all oriented in exactly the same way, though. 84 00:05:41,970 --> 00:05:44,220 So now let's look at giving it some rotation. 85 00:05:44,220 --> 00:05:50,820 So under our start rotation, let's again go with a random between two constants and go from zero degrees 86 00:05:50,820 --> 00:05:53,040 to 359 degrees. 87 00:05:53,040 --> 00:05:54,360 So a full circle. 88 00:05:54,450 --> 00:06:00,090 And we're also going to come down to rotation over lifetime and give it an angular velocity of around 89 00:06:00,090 --> 00:06:01,830 180 degrees. 90 00:06:01,830 --> 00:06:06,630 This allows our particles not only to be instantiated at a random angle, but also it gives it some 91 00:06:06,630 --> 00:06:08,340 rotation as they travel. 92 00:06:08,400 --> 00:06:13,530 So this is looking okay, but it is very sporadic and not very explosion yet. 93 00:06:13,530 --> 00:06:19,440 So now let's try and amp up the number of particles we've got and really condense them into a quick 94 00:06:19,440 --> 00:06:20,280 explosion. 95 00:06:21,060 --> 00:06:27,990 Up in our emissions, let's increase the rate over lifetime to say about 100, which is definitely giving 96 00:06:27,990 --> 00:06:32,190 us a more sparkly effect and to tighten up the radius a little bit. 97 00:06:32,220 --> 00:06:37,290 Let's go down to our shape and change the radius of our circle to maybe around 0.5. 98 00:06:37,650 --> 00:06:42,450 This has brought us a good step closer, and the next thing I'm noticing compared to our reference is 99 00:06:42,450 --> 00:06:45,360 that our particles are always exactly the same size. 100 00:06:45,360 --> 00:06:48,930 So down in size over a lifetime, let's enable that. 101 00:06:48,930 --> 00:06:54,810 And in our curve, let's flip this line so we start off big and eventually peter out to zero. 102 00:06:55,050 --> 00:06:57,930 This has drastically changed the look of our political system. 103 00:06:57,930 --> 00:07:02,130 So we now have a hot fire in the middle and these wispy smoke pieces around the edge. 104 00:07:02,460 --> 00:07:07,890 But to get it looking a little bit better, let's change the start speed so all of our particles aren't 105 00:07:07,890 --> 00:07:09,870 moving at exactly the same rate. 106 00:07:10,080 --> 00:07:14,400 Doing this will allow for a little bit of overlap in our speed and we'll have some bigger pieces of 107 00:07:14,400 --> 00:07:16,440 smoke fly out to start with. 108 00:07:16,440 --> 00:07:22,410 Let's try a random between two constants and maybe try somewhere between zero and two. 109 00:07:22,680 --> 00:07:26,760 And again, this has made quite a big difference, but it isn't quite what we want. 110 00:07:26,760 --> 00:07:32,070 And this is because when we do a random between two constants, the actual random numbers that get generated 111 00:07:32,070 --> 00:07:35,250 are evenly distributed between the upper and lower bound. 112 00:07:35,250 --> 00:07:39,180 But we really want more of our particles to be on the quicker end of things. 113 00:07:39,180 --> 00:07:41,190 To do this we can use a curve. 114 00:07:41,190 --> 00:07:42,600 So let's select that. 115 00:07:42,600 --> 00:07:47,670 And for this curve I'm going to want a nice ramp between zero and two. 116 00:07:47,700 --> 00:07:53,340 This means that we'll have more particles being created with a speed closer to two, and as we head 117 00:07:53,340 --> 00:07:57,240 down the curve, we'll end up with less particles at the slower speed. 118 00:07:57,270 --> 00:08:02,520 The final step now is going to be to change the duration of our particle system, because if we turn 119 00:08:02,520 --> 00:08:08,700 off looping and then restart our particle, it's existing for a very long time and explosion should 120 00:08:08,700 --> 00:08:10,500 be very short and sharp. 121 00:08:10,500 --> 00:08:16,560 So with looping turned off, let's set our duration down something nice and snappy, maybe around 0.2. 122 00:08:16,920 --> 00:08:21,090 And if we restart our explosion now, we get a nice short, sharp explosion. 123 00:08:21,630 --> 00:08:25,860 And with that final change, I'm pretty happy with the end result for this particle system. 124 00:08:25,860 --> 00:08:30,840 For now, it's pretty close to our initial reference and it looks quite nice. 125 00:08:31,080 --> 00:08:34,919 So with that set, let's go ahead and prefab our political system. 126 00:08:35,490 --> 00:08:39,480 And rather than calling it the particle system, let's call this the explosion effect. 127 00:08:41,309 --> 00:08:43,710 And we can delete that out of our hierarchy. 128 00:08:44,280 --> 00:08:48,450 Next, we want to instantiate this explosion whenever one of the ships is hit. 129 00:08:48,750 --> 00:08:54,000 So if we take a look at our script and think about where we could do this, the damage is being taken 130 00:08:54,000 --> 00:08:55,410 in our health script. 131 00:08:55,410 --> 00:08:59,550 So it'd be a good idea to have our health and our particle system linked in some way. 132 00:08:59,880 --> 00:09:03,360 Now, for this game, we're only going to have the one explosion effect. 133 00:09:03,360 --> 00:09:07,680 So I'm actually going to instantiate it directly into this health script. 134 00:09:07,680 --> 00:09:13,380 But if you decide to expand on this game later on and add more effect in other parts of your game, 135 00:09:13,380 --> 00:09:18,840 then it may be worth creating a brand new script that holds all of these special effects and then link 136 00:09:18,840 --> 00:09:21,330 that to the various scripts that need to call them. 137 00:09:21,660 --> 00:09:26,490 So in our Health script, let's create a serialized field for our particle system, and we're going 138 00:09:26,490 --> 00:09:28,500 to call this the hit effect. 139 00:09:29,280 --> 00:09:33,040 And we want to instantiate this particle effect whenever an object takes damage. 140 00:09:33,060 --> 00:09:38,610 Now, we could place this in our take damage method, but rather than muddying that up, let's create 141 00:09:38,610 --> 00:09:41,670 a new method called play hit effect. 142 00:09:43,380 --> 00:09:50,430 In here, we're going to say that if our hit effect does not equal null, so if we've attached a hit 143 00:09:50,430 --> 00:09:55,710 effect that we want to play, then we want to instantiate that effect so that we can destroy it later. 144 00:09:55,710 --> 00:09:57,720 Let's store this in a temporary variable. 145 00:09:57,720 --> 00:10:03,060 So for this one, we're going to need a particle system called instance, and then we can go ahead and 146 00:10:03,060 --> 00:10:08,520 instantiate our hit effect at the transform dot position. 147 00:10:08,520 --> 00:10:13,680 So at the position of the thing being hit and because we've included a position, we need to include 148 00:10:13,680 --> 00:10:17,730 a rotation of Quaternions identity for no rotation. 149 00:10:18,060 --> 00:10:26,010 Then to destroy the particles, we can say destroy the instance game object because the instance is 150 00:10:26,010 --> 00:10:32,310 currently just the particle system attached to a game object and for the duration we can get the duration 151 00:10:32,310 --> 00:10:39,420 of the particle system by saying instance dot main dot duration, and that will be the duration that 152 00:10:39,420 --> 00:10:41,370 the particles are being created. 153 00:10:41,370 --> 00:10:49,410 But we also want to include the lifetime of the particles so we can add the instance dot main dot start, 154 00:10:49,410 --> 00:10:55,290 lifetime dot constant max and you'll see a few different options here. 155 00:10:55,290 --> 00:10:58,890 And the one you select depends on how you set up the particle system. 156 00:10:58,890 --> 00:11:03,810 So we've got a minimum and a maximum value, but if you've set up a curve, you'll have to worry about 157 00:11:03,810 --> 00:11:05,760 animation curves and things like that. 158 00:11:05,970 --> 00:11:08,850 For this one, though, constant Max will do the job. 159 00:11:09,120 --> 00:11:13,890 Finally, we need to call this method from somewhere, so let's take our hit effect. 160 00:11:13,890 --> 00:11:17,670 And if we've dealt damage, we're going to take damage. 161 00:11:17,670 --> 00:11:23,430 We're going to play our hit effect and then we're going to tell our damage data to processes hit method. 162 00:11:23,430 --> 00:11:26,610 So let's save this up and test our immunity. 163 00:11:27,670 --> 00:11:31,910 Let's first of all, link our explosion to both our enemy and our player. 164 00:11:31,930 --> 00:11:34,520 So let's click both of those in our asset folder. 165 00:11:34,540 --> 00:11:38,950 Scroll down to our health script and then drag over our explosion effect. 166 00:11:39,160 --> 00:11:40,990 And then we can go ahead and hit play. 167 00:11:41,230 --> 00:11:43,870 And our particle systems are now being created. 168 00:11:44,230 --> 00:11:48,060 But if we notice, the particles are currently behind our ships. 169 00:11:48,070 --> 00:11:51,250 So have a quick think about how we might go and fix this. 170 00:11:52,860 --> 00:11:53,250 Okay. 171 00:11:53,250 --> 00:11:54,530 I'm not going to give you too long. 172 00:11:54,540 --> 00:12:00,470 If we jump into our explosion effect, scroll right down to the bottom where we have our renderer, 173 00:12:00,510 --> 00:12:02,970 because this is a problem with the sorting order. 174 00:12:03,030 --> 00:12:08,130 If you recall, we're currently working on a rough system of having our projectiles on layers zero, 175 00:12:08,340 --> 00:12:10,260 our ships on layer one. 176 00:12:10,260 --> 00:12:14,760 So for our particles, let's change our sort order in layer two to. 177 00:12:15,420 --> 00:12:18,180 If we save our prefab and then test again. 178 00:12:19,000 --> 00:12:24,220 We can see that the particles are now appearing on top of our ships, and when ships get destroyed, 179 00:12:24,220 --> 00:12:26,680 they go out in a bit more of a blaze of glory. 180 00:12:26,860 --> 00:12:30,430 So congratulations on creating your explosion particles. 181 00:12:30,430 --> 00:12:35,020 And in the next lecture, we're going to juice our game even more by adding some camera shake when the 182 00:12:35,020 --> 00:12:36,240 player gets hit. 183 00:12:36,250 --> 00:12:37,810 So I'll see you there.