 Hey guys it's DJ from iDesign.com and I'm here with part two of my springs and spline dynamics tutorials and this one is going to be about balloons and how you can get an upwards dynamic motion as opposed to a dropping objects hanging off of a string and dangling effect that I showed in part one. So I have my balloon object, I have my string object which is just a sweep nerve with a spline and a little circle set to a low radius and I got my materials applied so it's all good to go so far. So first we're going to start basically the same way as we did with the part one of the tutorial where first we got to add some dynamics to these objects. So we're going to add spline dynamics to the string, the string spline and we're going to go and select this, actually we're going to select this bottom, this is where we're going to have kind of like if a little boy is holding the balloon or whatever it's going to be holding it from the bottom of the string where this balloon is going to then react and revolve around this kind of center of axis of gravity or whatever you would call it so we're going to go and we're going to make that the fixed point so we're going to hit set and that will set that. Another big thing is since we're wanting upward motion because this is filled with helium usually so we want if we just left the gravity and dynamics as it is everything's going to drop and actually how you get to these project settings is hitting command D and that'll get you to all these settings here so what we're going to do is we're going to change this to a negative number I'm just going to go negative 500 and we'll see how that works everything else is good so all right we got our spline dynamics on there we need to add dynamics to our balloon as well so let's go and add a simulation rigid body tag there and then we need our string as well or spring sorry springs and strings so as I showed in the first first part you need to define two objects you know what's spring off what one's going to be holding the bottom of the spring and the other one's going to be spring off the top of the spring and we need our balloon to be object a and our string we want to actually bring in the string spline string into object B and we want the balloon we don't want it to be the center of mass we want it to be offset and it's going to be offset at the very bottom here so the like if the string was tied here the balloons going to be you know bouncing back and forth basically rotating off of this axis and the string we want it to go off of the point selection polygon point I'm sorry and basically what polygon point does is you can choose the index and you can see if it's at zero this top point of the spline is zero and when you see that I move it up it's going from I think this has seven or eight points so when I go up in the index number it's going to the next point in that index so I think if we get to yeah I think there was eight points so if we get to the very eighth point index that is referencing this very bottom so let's actually see what we got so far so that's not what we want because it's just bouncing back down what we need to do is jack up the rest length and see how it's kind of hanging out right there if we spring this to say 425 it's a little bit better we can actually offset to make sure that this extension is meeting up with the exact bottom of the balloon we can actually bring down the stiffness of the spring because we don't want it to be so so stiff right there so let's I found if we actually go to a very low value like point zero five we get a nice slight springiness going on we don't want it too much because a helium balloon usually doesn't go up very fast so that's looking good so far the one last dynamic thing we have to connect is the top of the the string here to the balloon so right now if we move our balloon and hit play it just kind of goes off doing its own thing and we need the the top of the string to move along with the balloon so one thing we got to do is go and add a constraint tag excuse me and make sure we have the top of the string spline connect selected and make sure that when you make your balloon the access center is down where the string would actually tie to the balloon which is important so let's bring the balloon as the object we want to set that point to and hit set so now if we go and move this balloon out here and hit play the top of the spline will now match up with the bottom of the balloon so that's looking good so far but if you actually don't want to manually go and animate your balloon what you can do is add some some turbulence or even some wind to make things interesting so let's make sure our fans turn the right direction so now you have this wind going you have some turbulence we bring that up and bring that so now you have it it's a little bit too crazy you see it's kind of freaking out some turbulence the wind as well so that's looking it's looking okay I would like it the balloon to start a little further down so we have more of the string movement so how you can do that is change the rest length and bring that to 350 and now we have a little bit dampening up so a lot of this is just playing around with these settings here and seeing what looks best so maybe we want to bring the rest length back the stiffness is good like seeing that the movement of the string actually go in and play with the spline dynamic settings and we bring down the rubber option and maybe drag up and bring the stiffness to do to see how that works our timeline here so we can get a little bit longer dynamic simulation going let's be having pretty good remember there's this is like it's a balloon connected to like wrapped around a pole or something like that so that's looking pretty believable it's still like to get a little bit more movement actually if we bring down our rotational mass and what this does is actually makes it makes the balloon more likely to change its rotation off of it this mass center and when we bring that down we can actually change where the center of where the masses so usually you know it's a little bit top heavy because everything's you know all the helium is you know wanting to go up so we probably want to move the center up maybe 150 we can actually see what the units are to get to the top it's about 230 so it changes about 200 we want to go to the very tip top we kind of want to be in that range maybe even 190 let's play this again so now you can see it's a little bit more we've got a little bit more rotation with the actual balloon which is nice actually don't like how much gravity there is going up so let's actually go hit command D and let's go back to our general and let's make that a negative 100 instead so we got a little bit more got a lot of a lot of jerking is going to bring down the wind because since we loaded the gravity we don't need as much wind or turbulence to make things move let's go back to our spring and spring is dampening up maybe that'll stop that spring the wrestling up I think that's what's causing that weirdness right there that was just when you when you get the rest length off with the actual length of the spline that's gonna make things a little bit weird as you saw so too much too much so let's just get rid of the wind all together let's just bring turbulence back our turbulence moving scale down basically we just want some decent enough movement or doesn't look so boring just staying static like that right so let's look I'm pretty pretty good now um now let's actually bring a few more into the scene and like I did before the way to set this up so you can duplicate it is just making a knoll making sure the knoll is position positioned to the bottom of the string that's where we're gonna like offset the rotation of more of these balloons and strings let's duplicate that and we can move that out of the way and yeah to actually edit and move the rotation make sure you're on frame zero because if you're not on frame zero that's when the dynamics start to kick in and it'll actually lock lock it so you can't change the attributes of the objects you're working with so all right now we hit play and you got the balloons bouncing off each other look pretty nice so I mean that that works this option is good if you just need to have some balloons connected to another object that's kind of stationary there's another option I'm going to show that works a little bit better if you want to actually animate have the in the balloons just kind of float up so yes that this is good if you just want to connect it to one point but with the spring you're kind of limited to the spring movement and stuff so if I actually move this stuff along see because it's a spring it wants to kind of compress and it doesn't come back in it's kind of stiff and no matter how how much you change the spring stiffness and all that stuff that doesn't really change just because of the nature of that object so the next this next way to get some dynamic balloons is still with the dynamics and string dynamic spline dynamic sorry get all set back up again so yeah you you let's get a string back actually all these guys okay so you you still want to add your dynamics to the balloon you still want to have your spline dynamics for the for the string the only thing you need to do is fix the look instead of before how I fix the bottom point that's fine so well and dandy when you want to connect it to something that's that the string is tied on to but this we just want it to kind of float freely into the air so we just need to make sure that this this top point is just connected to the balloon so let's go and set that point and actually if we make this whole object a child of the balloon what it's going to do is use the dynamic dynamics of this balloon object and it's going to bring everything else up it's going to bring the string up and since we set the point to where it would be tied to the balloon if we hit play it's just gonna go straight up and it looks pretty boring as is so all we need to do is just like the other scene where the balloon was attached at the bottom there just gonna bring some turbulence into here 35 and now you can start seeing it interact the turbulence is going to interact with that spline as it goes up bring some scale in there you start to see the balloon move and also move the string along with it so it's looking a little bit more believable of how balloon would actually go up into the air so pretty happy with how that looks so far now what we can do is bring in a couple other balloons for them to kind of interact with each other so it's gonna drag them the whole entire thing into a knoll and bring the axis center down there of the knoll so I can kind of when I duplicate I can offset the rotation like so bring this over here a little bit hit play someone's gonna lose their balloons actually sometimes that happens if that ever happens where right away when you hit play the splines kind of go crazy hit back a few times and that should straighten out the dynamics there so so now you got a bunch of balloons going in a bunch of different directions we can get to bounce off each other we got a little bouncing they're going up you can see that some of these are rotating in a weird way you know balloons don't do that so what we need to do going to these tags here and it's jack up the rotational mass so they don't rotate as much as they bounce so now they're going in a much more believable way up into the air never tie an engagement ring to a balloon you've heard that story that was a bad idea guy lost his engagement ring I don't know if the girl dumped him after that probably should have because I was dumb all right so there is your dynamic balloons render that out so yeah there was two there's two ways the one where it connects with the spring and this one's a little bit more free floating let me know if you have any other ways I know there's probably a bunch of different ways you can get this balloon effect going but I'd love to hear the comments and your feedback so post them below and I'll see you in part three of the springs and spline dynamics tutorial extravaganza thanks for watching bye