1 00:00:04,300 --> 00:00:05,350 ‫Hello and welcome. 2 00:00:05,350 --> 00:00:10,840 ‫This lecture we're going to be sorting out the colliders on our barrels so that we can stack them up 3 00:00:10,840 --> 00:00:15,880 ‫properly, as you can see here, and have fun just plowing into them and knocking them down. 4 00:00:15,880 --> 00:00:18,100 ‫Let's dive in and see how this is done. 5 00:00:19,140 --> 00:00:19,530 ‫Okay. 6 00:00:19,530 --> 00:00:23,750 ‫So I would like to be able to stack items on top of this rack. 7 00:00:23,760 --> 00:00:30,240 ‫Now, we can do this fairly straightforwardly by just getting a barrel and dragging it on to the rack. 8 00:00:30,240 --> 00:00:35,910 ‫And you can see Unreal automatically tries to position it on top and we can do that effectively. 9 00:00:35,910 --> 00:00:41,490 ‫Then we can hit simulate physics and we can hit play and see that it jumps around a little bit, but 10 00:00:41,490 --> 00:00:42,720 ‫not massively. 11 00:00:42,720 --> 00:00:43,800 ‫So that's quite cool. 12 00:00:43,800 --> 00:00:50,130 ‫And we can now shoot at the rack and have everything fall down in the process. 13 00:00:50,130 --> 00:00:50,520 ‫It's funny. 14 00:00:50,520 --> 00:00:55,470 ‫It's kind of got its legs stuck in the ground though, which is a little bit annoying. 15 00:00:55,620 --> 00:00:58,200 ‫We will work on tweaking some of these bugs. 16 00:00:58,200 --> 00:01:02,220 ‫It may well be that the mesh is a little bit too far on the ground. 17 00:01:02,220 --> 00:01:08,640 ‫If we select the mesh and the barrel and bring it up slightly, then it shouldn't be penetrating the 18 00:01:08,640 --> 00:01:12,150 ‫ground and hopefully won't get stuck in the way that it just did. 19 00:01:12,150 --> 00:01:16,590 ‫And we've got a little bit of a fun set up that we can knock stuff over. 20 00:01:16,590 --> 00:01:25,800 ‫However, you will notice if you tried or did try earlier to stack these barrels on top of each other, 21 00:01:25,800 --> 00:01:31,830 ‫they can get pretty unstable pretty quickly, even if we give them a little bit of separation so that 22 00:01:31,830 --> 00:01:38,040 ‫we know they aren't clipping into each other and popping because of that reason, we give them a little 23 00:01:38,040 --> 00:01:42,540 ‫bit of separation, but let's select them both because they haven't got physics enabled. 24 00:01:42,540 --> 00:01:44,340 ‫Let's select them both and add physics. 25 00:01:44,340 --> 00:01:51,870 ‫If I duplicate this and bring up another level and make sure my tower is nice and straight, and if 26 00:01:51,870 --> 00:01:58,800 ‫we hit play now, we see that it pops up in the air like this and is incredibly unstable. 27 00:01:58,800 --> 00:02:00,510 ‫So why is it doing this? 28 00:02:00,510 --> 00:02:02,400 ‫Why is it being so unstable now? 29 00:02:02,400 --> 00:02:08,970 ‫The reason for this is because of collisions and the way collisions are calculated in Unreal. 30 00:02:09,000 --> 00:02:13,560 ‫There is a mesh here which is essentially let me show you what a mesh is. 31 00:02:13,560 --> 00:02:18,570 ‫Actually, if we go to the viewport and hit the button that currently says Lit and select wireframe 32 00:02:18,570 --> 00:02:21,150 ‫instead, this is what the mesh is. 33 00:02:21,150 --> 00:02:26,880 ‫This is essentially what the computer is seeing and rendering for us with the application of materials. 34 00:02:26,880 --> 00:02:30,630 ‫So you can see there's this complicated looking mesh for the barrel. 35 00:02:30,630 --> 00:02:33,180 ‫But this isn't what is used for physics. 36 00:02:33,180 --> 00:02:34,530 ‫No, for physics. 37 00:02:34,530 --> 00:02:39,480 ‫There is a simplified version of this mesh to make physical calculations a lot easier. 38 00:02:39,480 --> 00:02:46,290 ‫So if you click where it now says wireframe instead we can change the view mode down to player collision. 39 00:02:46,290 --> 00:02:48,870 ‫And this shows us the simplified collision mesh. 40 00:02:48,870 --> 00:02:56,130 ‫And you can see it's a little bit wonky, it's a little bit jagged and not ideal for having clean collisions. 41 00:02:56,130 --> 00:02:57,600 ‫So we can change this. 42 00:02:57,600 --> 00:03:04,680 ‫We can modify the collision mesh fairly easily and unreal by going to the content draw and selecting 43 00:03:04,680 --> 00:03:12,690 ‫our barrel mesh and double clicking it, which brings up the static mesh editor and we can see what 44 00:03:12,690 --> 00:03:13,620 ‫the mesh is like. 45 00:03:13,620 --> 00:03:14,910 ‫We can kind of click on it. 46 00:03:14,910 --> 00:03:21,990 ‫We can look at the wireframe view again by clicking on lit and switching to wireframe or switching to 47 00:03:21,990 --> 00:03:23,130 ‫player collisions. 48 00:03:23,130 --> 00:03:30,690 ‫And what we can do is there is a collision button in the toolbar and we can click on that and click 49 00:03:30,690 --> 00:03:36,870 ‫remove collisions, which is going to remove any collisions that are currently there, such as slightly 50 00:03:36,870 --> 00:03:38,100 ‫janky collisions. 51 00:03:38,190 --> 00:03:43,680 ‫If we go back to the main level, you can see there's now no mesh visible in our player collisions. 52 00:03:43,680 --> 00:03:47,700 ‫And if we hit play you can see they just pass straight through the floor because there's nothing for 53 00:03:47,700 --> 00:03:48,810 ‫them to collide with. 54 00:03:48,810 --> 00:03:55,980 ‫So what we need to do is go back to our mesh editor and select the collision dropdown again. 55 00:03:55,980 --> 00:04:02,490 ‫And we can do we can add in a simplified collision that is going to be much better suited for this. 56 00:04:02,640 --> 00:04:10,020 ‫And what we want to do is add the ten dop z axis simplified collision. 57 00:04:10,020 --> 00:04:11,790 ‫Now, let me just explain this. 58 00:04:11,790 --> 00:04:13,850 ‫In fact, the tooltip kind of explains this. 59 00:04:13,860 --> 00:04:21,930 ‫It says it generates a new axis aligned box collision mesh with four Z axis aligned edges, beveled 60 00:04:21,930 --> 00:04:23,850 ‫and ten total sides. 61 00:04:23,850 --> 00:04:28,890 ‫That's pretty confusing, but if I add it in, it might make it a little bit clearer. 62 00:04:28,890 --> 00:04:29,700 ‫I've add it in. 63 00:04:29,700 --> 00:04:35,070 ‫You can see this is what the mesh actually looks like and you can see what it's sort of meant by Z axis 64 00:04:35,070 --> 00:04:35,760 ‫aligned. 65 00:04:35,970 --> 00:04:42,780 ‫It's most of its complexity is around the Z axis trying to wrap around this barrel and it's flat on 66 00:04:42,780 --> 00:04:48,930 ‫the tops and the bottoms, which is exactly what you want really when you're trying to model a barrel. 67 00:04:48,930 --> 00:04:51,810 ‫So I'm pretty happy that that's a good collision mesh. 68 00:04:51,810 --> 00:04:58,440 ‫We can now save the mesh, go back to our level and you can see that the player collision view is showing 69 00:04:58,440 --> 00:05:03,720 ‫us the new collision mesh, which is a lot simpler and less deformed. 70 00:05:03,720 --> 00:05:10,560 ‫So I can now switch the view mode back from player collision to lit and we can see all the lighting 71 00:05:10,560 --> 00:05:17,010 ‫and materials and we can go ahead and hit play now and you can see that these barrels are a lot more 72 00:05:17,010 --> 00:05:18,600 ‫stable than they were previously of. 73 00:05:18,700 --> 00:05:22,150 ‫See when I go ahead and hit them, they aren't any more. 74 00:05:22,150 --> 00:05:28,510 ‫So I'm going to challenge you to create a blueprint barrel class here so that we don't have to go and 75 00:05:28,510 --> 00:05:31,930 ‫change settings on every single barrel all the time. 76 00:05:31,930 --> 00:05:34,990 ‫So go and click that convert to blueprint button. 77 00:05:34,990 --> 00:05:40,660 ‫Just a reminder, it's the one in the details pane that looks like a little tiny blueprint graph. 78 00:05:40,660 --> 00:05:44,740 ‫Then you're going to keep the defaults and just change the name. 79 00:05:44,740 --> 00:05:48,550 ‫And remember that we use the BP underscore naming convention. 80 00:05:48,880 --> 00:05:50,710 ‫I'd like you to increase the barrel mass. 81 00:05:50,710 --> 00:05:57,340 ‫At the moment they are very flimsy and fly around very easily when hit and build a wall out of these 82 00:05:57,340 --> 00:06:01,540 ‫barrel out this barrel class and have fun knocking it over. 83 00:06:01,540 --> 00:06:03,190 ‫Pause the video and have a go. 84 00:06:06,310 --> 00:06:06,940 ‫Okay. 85 00:06:06,940 --> 00:06:07,650 ‫Welcome back. 86 00:06:07,660 --> 00:06:10,740 ‫So let's create a barrel class, shall we? 87 00:06:10,750 --> 00:06:18,100 ‫So I'm going to take one of these barrels and I'm going to hit the convert to blueprint. 88 00:06:18,100 --> 00:06:25,930 ‫Then I'm going to change the name to BP, underscore barrel, and I'm going to change the path as well 89 00:06:25,930 --> 00:06:29,680 ‫so that it's in the root of the content folder and hit select. 90 00:06:29,680 --> 00:06:33,460 ‫Then it's going to automatically open up our newly created class. 91 00:06:33,460 --> 00:06:38,950 ‫I'm going to dock this to the main window and I'm going to go and select the static mesh components. 92 00:06:38,950 --> 00:06:42,530 ‫Scroll on down to the physics section, make sure physics is enabled. 93 00:06:42,550 --> 00:06:43,270 ‫It is. 94 00:06:43,270 --> 00:06:50,620 ‫I'm going to increase the mass to about I think 1000 in my testing has been quite fun in the past and 95 00:06:50,620 --> 00:06:55,690 ‫I'm going to save the blueprint and now I'm going to delete the barrels that I currently have in my 96 00:06:55,690 --> 00:06:59,320 ‫scene because I want to use my new barrel class instead. 97 00:06:59,320 --> 00:07:07,030 ‫Then we're going to go ahead and open up the content drawer and drag in a barrel instance into our scene. 98 00:07:07,030 --> 00:07:10,810 ‫And I want to stack these up in to a wall. 99 00:07:10,990 --> 00:07:13,600 ‫Before I do that, I'm going to stick them inside a folder. 100 00:07:13,600 --> 00:07:19,540 ‫So I'm going to right click in the outline on the newly created barrel, and I'm going to select the 101 00:07:19,540 --> 00:07:26,320 ‫move to option create new folder, and I'm going to call this barrel wall with no spaces just because 102 00:07:26,320 --> 00:07:27,520 ‫that's my preference there. 103 00:07:27,520 --> 00:07:34,960 ‫And then selecting that barrel, I'm going to click on the Z axis to drag the barrel up and then repeat 104 00:07:34,960 --> 00:07:38,590 ‫and probably one more time to make it nice at all. 105 00:07:38,590 --> 00:07:44,470 ‫Then selecting all four of those I can duplicate out to the side a couple of times, then selecting 106 00:07:44,470 --> 00:07:48,040 ‫all the barrels in the outline and moving myself to the side. 107 00:07:48,040 --> 00:07:55,990 ‫I can alt click on the red arrow to bring a couple of rows backwards of my barrels like so, and we 108 00:07:55,990 --> 00:07:59,440 ‫probably want some stacked here on top of the rack as well. 109 00:07:59,440 --> 00:08:06,970 ‫So let's go back to a content drawer and drag in from there a couple of barrels for our rack and some 110 00:08:06,970 --> 00:08:08,560 ‫for the top as well. 111 00:08:08,560 --> 00:08:12,580 ‫And while we're at it, let's stack a few of these on top of each other. 112 00:08:12,620 --> 00:08:15,760 ‫Should make them more fun to knock down when we do. 113 00:08:15,760 --> 00:08:18,220 ‫So, let's play and see what this looks like. 114 00:08:18,220 --> 00:08:22,630 ‫So I've got my barrel wall dominating here in front and I've got the rack. 115 00:08:22,660 --> 00:08:24,160 ‫Let's try shooting at the rack. 116 00:08:24,160 --> 00:08:29,350 ‫Well, that's very satisfying to knock those over and then we can shoot at this barrel wall as well 117 00:08:29,350 --> 00:08:32,260 ‫and create a lovely bit of carnage. 118 00:08:32,380 --> 00:08:37,540 ‫Now, you may notice that occasionally the ball goes flying through the walls or the barrels, and this 119 00:08:37,540 --> 00:08:42,340 ‫is because it's moving so fast that the physics simulation doesn't really keep up. 120 00:08:42,340 --> 00:08:44,560 ‫Now we won't be fixing it in this section. 121 00:08:44,560 --> 00:08:47,860 ‫It's a little bit beyond the scope of what we're trying to do. 122 00:08:47,890 --> 00:08:54,160 ‫So one thing you can do to ameliorate this if you want to, is to reduce the speed of the balls and 123 00:08:54,160 --> 00:08:55,840 ‫it will happen less often. 124 00:08:56,020 --> 00:08:57,130 ‫Great stuff. 125 00:08:57,130 --> 00:09:02,620 ‫So hopefully you've enjoyed putting some barrel physics in here and getting the colliders working and 126 00:09:02,620 --> 00:09:04,030 ‫I'll see you in the next lecture.