WEBVTT 00:00.210 --> 00:03.660 Welcome to force fields and other objects. 00:03.660 --> 00:10.850 So they act slightly differently when force fields are applied to different objects themselves. 00:10.980 --> 00:17.040 Now they are aware of exerting different forces onto our models just like they have always been with 00:17.040 --> 00:19.650 particles now as well as particles. 00:19.650 --> 00:24.690 They will affect soft bodies rigid bodies and cloth objects as well. 00:24.720 --> 00:30.510 So it's worthwhile bearing in mind you can use them with several of the physics models. 00:30.570 --> 00:34.460 Now there is a shift in set up compared with particles. 00:34.530 --> 00:41.460 And the reason for that you will see in a moment um hope it's going to be buggy so you can see why we 00:41.460 --> 00:47.250 need to set it up slightly differently and then we'll have a look at how to make an object completely 00:47.340 --> 00:49.710 unaffected by certain forces. 00:49.710 --> 00:53.790 Now this can be important if you want part of your scene to stay put. 00:53.850 --> 01:01.320 Was making the other part of it explode dramatically perhaps in a real heroes or a realistic physics 01:01.320 --> 01:03.430 cingulate and the whole lot would get obliterated. 01:03.510 --> 01:10.320 But you might not want that to happen for more artistic effects or more had choreographed effects shall 01:10.320 --> 01:10.910 we say. 01:11.070 --> 01:17.630 So let's go play it with force fields and other objects in this case were play with rigid bodies over 01:17.630 --> 01:18.640 in blender. 01:19.050 --> 01:20.920 Okay so welcome back to blender. 01:20.940 --> 01:27.180 Now my default starting scene looks a bit different to how I set it up before I had a bit of a computer 01:27.180 --> 01:28.170 wobbly. 01:28.220 --> 01:32.710 I've sorted that out but unfortunately I've got my default scene back as this. 01:32.730 --> 01:38.610 So there will be some things that I have to redo don't worry assist me resetting up my computer and 01:38.610 --> 01:41.740 silly me I didn't back up the actual blend start file. 01:41.850 --> 01:44.800 So I was left with that offer anyway. 01:45.180 --> 01:51.600 So let's start by giving this cube in the physics properties a forcefield and a rigid body. 01:51.870 --> 01:55.860 Now just like the particles it won't self affect. 01:55.890 --> 02:01.770 So let's add another one into the scene some just going to duplicate that and pop it over here. 02:01.920 --> 02:09.450 Now the forces needed to move objects is often a lot higher especially rigid bodies than particles so 02:09.450 --> 02:15.000 whereas particles would be streaming everywhere of whoop play is not guaranteed in this case so just 02:15.000 --> 02:21.150 to make sure if we do have any effect at all I'm going to set the strength of both of those force fields 02:21.150 --> 02:27.420 to 100 and then we when we press play Oh we haven't turned off gravity yet. 02:27.430 --> 02:32.380 No reason why are we turning off gravity as simply so we can see the effect of the force fields by themselves. 02:32.530 --> 02:37.090 And under this set the end frame to 100 as well and did are. 02:37.170 --> 02:38.520 And let's let it reset. 02:38.520 --> 02:40.670 No they're not doing anything now. 02:40.680 --> 02:45.360 I've had this trouble before you think they would affect one another but not themselves but with those 02:45.360 --> 02:47.120 settings they just don't. 02:47.160 --> 02:55.170 Now I've turned forcefield of field on rigid body off rigid body on and occasionally they actually react 02:55.200 --> 02:55.930 and start B. 02:55.950 --> 02:59.530 What I say behaving themselves as we'd expect them to. 02:59.610 --> 03:03.870 But of course each time you turn these things on and off you actually lose the settings you have before 03:03.870 --> 03:05.520 so that's not ideal. 03:05.580 --> 03:08.150 So this is where the set up change comes. 03:08.210 --> 03:10.380 It will start to become important. 03:10.530 --> 03:18.510 So what we need to do here is instead of actually attaching it directly to there is just like we did 03:18.510 --> 03:21.030 with the particles we add a separate force field. 03:21.030 --> 03:24.090 Sorry go ahead and add a force force field here. 03:24.210 --> 03:28.110 We can already see it starting to push that cube away this one on the right. 03:28.290 --> 03:30.010 So let's go ahead and just increase. 03:30.010 --> 03:35.400 That's maybe 10 and we can see it pushing away and obviously if we set it to minus 10 it will pull it 03:35.400 --> 03:36.540 towards it. 03:36.640 --> 03:41.230 Now once we've started it moving like this we should see them bump into one another. 03:41.270 --> 03:43.340 Oh no we have not got enough frames. 03:43.560 --> 03:44.930 So there's two ways of dealing with that. 03:44.940 --> 03:47.010 And I'm just going to increase the force. 03:47.010 --> 03:50.550 Now they're knocking to one another and then be pulled back. 03:50.550 --> 03:56.400 Did you see that they started to slow down and that's because the force itself is not parenting to the 03:56.400 --> 03:57.210 other cube. 03:57.420 --> 04:01.620 Says the other Q moves the force itself does not. 04:01.620 --> 04:04.860 So we can link those two together imperent them if we wanted to. 04:05.100 --> 04:12.810 Now one of the things you may want to do is let's say let's duplicate another cube just over here and 04:12.870 --> 04:14.290 they all get pulled in. 04:14.930 --> 04:19.850 Now say we wanted this new cube to not get affected by the physics will simply we could turn the physics 04:19.850 --> 04:20.310 off. 04:20.480 --> 04:26.090 However if we still wanted other things to bump into it would still need collision or even perhaps a 04:26.090 --> 04:27.090 rigid body. 04:27.200 --> 04:32.480 But what we want in this case is it not to be affected by this particular force field. 04:32.810 --> 04:34.860 As a couple of ways of doing that. 04:34.910 --> 04:40.400 Number one we can literally move that to another layer that the force feels not on and then it will 04:40.400 --> 04:44.650 not be affected by that force field as we can see here. 04:45.970 --> 04:50.440 That is one way of doing it and then when we bring the two together because they're on separate layers 04:50.830 --> 04:53.370 one will not affect the other. 04:53.440 --> 04:58.810 Let's just reset the simulation and we can see moving things about cause it to go just a little wobbly 04:58.960 --> 05:04.030 but it's unaffected and that's the easiest way to do it to put things on layers that affect one another 05:04.360 --> 05:05.740 and not on others. 05:05.740 --> 05:10.780 Now if you wanted it if it was a particle system itself and we can see this is now emitting particles 05:11.050 --> 05:18.310 you can scroll down there to field weights and well we can change all of the ones that we want to hear 05:18.310 --> 05:23.100 so we can set gravity to have more or less effect on these particles. 05:23.170 --> 05:24.090 The force. 05:24.100 --> 05:26.660 This one over here to have more or less effect. 05:26.680 --> 05:30.840 Of course what we've got at the moment is it on a different layer so it won't affect it all. 05:30.850 --> 05:32.720 We popped it back onto layer 1. 05:32.860 --> 05:36.310 You'd see these particles being attracted in. 05:38.050 --> 05:38.900 There we go. 05:39.010 --> 05:40.240 Once you turn the force up. 05:40.240 --> 05:45.220 However if you make the force zero then they just get emitted and scattered. 05:45.220 --> 05:46.630 Hey that looks like a comet. 05:46.630 --> 05:48.020 How cool is that. 05:48.250 --> 05:52.950 Okay so we're ready now to set you up for a little challenge. 05:53.410 --> 05:57.840 Okay so your challenge is all about meche objects affecting each other. 05:58.060 --> 06:03.050 So use a force field to make two or more meche objects affect one another. 06:03.130 --> 06:04.630 Things to try. 06:04.630 --> 06:08.440 Well we've got a wall that's already having a projectile hitting it. 06:08.440 --> 06:14.370 How about setting up an explosion which happens when the projectile hits our wall. 06:14.590 --> 06:18.650 And perhaps you want some of the bricks not to be forced out by the explosion. 06:18.650 --> 06:20.120 That's something to think about. 06:20.740 --> 06:22.210 Now something extra you can do. 06:22.210 --> 06:27.460 And I found this quite funny and I show you a clip of it after I've completed my challenge is getting 06:27.490 --> 06:29.380 objects to orbit one another. 06:29.410 --> 06:33.270 That's great fun and prehaps you will find a use for it as well. 06:33.400 --> 06:36.160 I certainly found it as I say a lot of fun anyway. 06:36.340 --> 06:39.570 So go ahead pause a video and give that a go. 06:41.670 --> 06:43.320 Okay guys welcome back. 06:43.380 --> 06:45.660 Let's go have our wall exploding. 06:45.660 --> 06:48.620 When the projectile actually hits the wall. 06:49.000 --> 06:53.990 Okay so I've opened up my wall here and let's just recap on what's happening here. 06:54.000 --> 06:55.540 Let's play the animation. 06:55.770 --> 06:59.720 Oh the help of we had a time line as well so we can see what's going on. 07:00.570 --> 07:07.870 Okay so what we can do here is step through and say its all 20 it's okay. 07:08.980 --> 07:10.360 It's impacted. 07:10.400 --> 07:18.530 They're actually in the wall at that point so I can set myself a forcefield coming on at frame to end 07:18.550 --> 07:18.880 too. 07:19.060 --> 07:23.650 So let's go back to frame 0 and I will need the force and that's very tempting. 07:23.650 --> 07:26.590 I've done it in practice as adding the force field to this object. 07:26.590 --> 07:31.940 It won't do anything as we've already discovered it totally ignore everything you've got going. 07:31.960 --> 07:38.560 So we've got our projects let's go ahead and move the cursor to select it so we pop the cursor there 07:38.920 --> 07:45.190 and I am going to do a bit of tidying up because this is driving me just a little bit bonkers that we've 07:45.190 --> 07:47.590 got all of this mess. 07:47.630 --> 07:49.650 So what should we do here. 07:49.660 --> 07:51.470 Let's parents. 07:51.820 --> 07:58.790 Well certainly that parent in the field to that cone and call the cone projectile. 07:59.160 --> 08:00.430 Excellent. 08:00.490 --> 08:03.840 And scroll down and I will. 08:03.850 --> 08:05.110 Well we added the force. 08:05.140 --> 08:12.690 No we haven't so let's add a force field force and parent it to the actual projectile. 08:12.700 --> 08:19.340 Otherwise when the projectile moves our are actually forceful or not. 08:19.390 --> 08:24.600 So that goes in and doesn't seem to do anything let's set a force of 100. 08:26.870 --> 08:28.400 And that also doesn't seem to do anything. 08:28.400 --> 08:30.590 So that's sort of five hundred. 08:32.700 --> 08:36.570 We can see is pushing the wall over as it comes towards. 08:36.570 --> 08:42.520 And what I'm hoping is for the Brits to go absolutely flying so let's do five five thousand. 08:42.630 --> 08:43.290 There we go. 08:43.290 --> 08:46.950 That's pretty impressive how Kate's now we got that. 08:46.950 --> 08:49.160 So we've got an approximate force. 08:49.260 --> 08:54.630 We actually want it to be zero at the very beginning have said it's a zero I'm going to press to key 08:54.630 --> 08:56.980 it in an hour at this. 08:58.300 --> 09:06.070 It's cached some information about there actually some set it frame it when it first starts nudging 09:06.100 --> 09:11.070 and going to set again the strength at zero and by twenty five. 09:13.230 --> 09:19.290 Unlost suddenly set the strength twenty six so yeah about there an MMA set the strength the five fouls 09:19.320 --> 09:25.410 and an unknown to turn up the power to the power of two just so it fades away so it's not constantly 09:25.710 --> 09:27.730 pushing things a way. 09:27.900 --> 09:35.970 Okay so let's see how that looks when we play it back so it should go being oh you know I didn't do 09:36.330 --> 09:39.710 I didn't actually key in that last thing so let's play it through. 09:39.890 --> 09:45.510 Scott all if we don't play it through it starts ruining itself because things aren't cached So we got 09:45.570 --> 09:51.680 zero here zero here and at 25 I won it five thousand. 09:51.900 --> 09:53.960 And remember to quit this time there we go. 09:54.070 --> 09:55.830 So it start from the beginning. 09:55.830 --> 09:56.650 Boom. 09:58.010 --> 09:58.710 Okay. 10:00.220 --> 10:01.480 Let's try. 10:01.480 --> 10:07.630 Fifty thousand that did that didn't do any of this try on the right place 15 1 2 3. 10:07.840 --> 10:11.340 I didn't have the effect I wanted it to go back and. 10:12.130 --> 10:14.390 So the effect ramps up. 10:15.270 --> 10:16.810 Oh only five thousand again. 10:16.840 --> 10:17.610 Fifty. 10:19.200 --> 10:22.920 And why not keep it in my kerson Must not have been over. 10:22.920 --> 10:24.260 Pretty sure I did that. 10:27.160 --> 10:29.070 Oh something weird goes on there. 10:34.340 --> 10:36.910 Okay so the power was a bit too high. 10:36.920 --> 10:42.130 That works but I'm going to have it ramp back down again. 10:43.370 --> 10:49.670 So it's not an A not a continuous force just a sudden force back to zero almost straight after like 10:49.670 --> 10:54.220 a real explosion because after you get the shock wave not continuous force. 10:54.670 --> 10:56.510 Okay that works brilliant. 10:56.510 --> 11:03.410 So the final thing here is just to keep some of the wall intact and make it basically on a different 11:03.410 --> 11:03.740 layer. 11:03.740 --> 11:11.180 And I'm just going to randomly select some bricks hopefully getting a bit bigger as we get to the bottom. 11:11.240 --> 11:12.360 There we go. 11:12.650 --> 11:15.660 And perhaps a set over here as well. 11:15.830 --> 11:20.690 So that's a rough selection there need a couple more in there. 11:20.690 --> 11:26.810 Very exciting me selecting bricks are there apologizing going to move and hot to layer all two or three 11:26.810 --> 11:30.260 in this case because of accidentally moved them to three. 11:30.520 --> 11:32.760 So let's turn on layers 1 and 3. 11:33.050 --> 11:36.890 And now they shouldn't affect one another so that send in our projectile. 11:36.890 --> 11:37.900 Boom. 11:37.910 --> 11:41.660 But they are affected by just falling over. 11:41.720 --> 11:43.460 They are affected by each other. 11:43.980 --> 11:46.480 Excellent sort of gone explosive impact there. 11:46.500 --> 11:51.570 Exactly what I wanted to see is that as the projectile comes through. 11:51.600 --> 11:52.340 Perfect. 11:52.350 --> 11:53.630 How did you guys get on. 11:53.620 --> 11:55.310 Did you manage to destroy a wall. 11:55.320 --> 12:00.140 Did you have the same sort of issues I did with the strength you had to turn up and play with it. 12:00.150 --> 12:04.400 It can be quite interesting trying and get the right settings and I'm happy with this. 12:04.510 --> 12:09.630 And there was this final thing that I wanted to show you so I will show you this orbiting collision 12:09.630 --> 12:10.350 that I set up. 12:10.350 --> 12:15.880 It took quite a while to read because of all the physics involved but it was great fun setting up. 12:17.250 --> 12:24.030 Okay so I I honestly I can't remember how many little balls there are in this scene but they've all 12:24.030 --> 12:27.880 got their own little forcefield and they're all attracted to one another. 12:27.930 --> 12:33.280 And of course when a big bunch of them get together well they attract more so than anything else. 12:33.300 --> 12:37.530 So he have them orbiting together and eventually forming. 12:37.800 --> 12:42.440 Well I don't know what you call it a planet perhaps with all these satellites going around it. 12:42.540 --> 12:48.330 If I just speed up this process you will see that eventually you get a solid moon of three of these 12:48.330 --> 12:50.680 little spheres orbiting as well. 12:51.700 --> 12:52.750 That was great fun. 12:52.750 --> 12:54.060 I enjoyed it anyway. 12:54.230 --> 12:59.710 So I'd love to see what you guys have come up with remembered to share over on the forum and I will 12:59.710 --> 13:02.430 see you guys in the next lecture.