CREATE A DYNAMIC FISH: Quick Tip [Blender 2.8]

Hi, I'm Luciano and today I want to show you how to make this fish that has a dynamic tail. Basically what you see here is based on a demo I saw on internet for cinema 4d dude and all it has is a bunch of bones a bunch I would say it's only four dynamically driven bones cage that has cloth and the fish and that's it and there's one bone that actually contains hand-keyed animation which is this one okay as you can see has here some little keyframes that make him jump and that's it so without further ado let's just go get right into it Here we are we have a clean scene with just a fish that I named fish001 by the way this fish I got it from Sketchfab and the author I don't remember his name but I know I have it written down so I'll put it down in the comments and here we are so this is a clam fish I think and what we'll do basically is we're gonna first add some bones that can deform it so for that I'm just gonna go shift a armature single bone this bone because it will go inside the this guy it will probably disappear as you can see so if I go into x-ray you see that my bone has disappeared or it's inside the mesh and I want to see him all the time so I'll just go here and just make mark him as in front no matter what type of vision or viewport or I don't know how you call this I am you're gonna see him anyways so let's just go back to loop depth because it looks pretty and it's more obviously it's nicer to work with pretty stuff and I'm just gonna go change in I'm gonna go to edit mode and I'm gonna change my pivot to active elements so I can rotate it from the bottom so rotate in 90 degrees and I'm gonna place this first bone more or less where where the fish kind of stays still like if you see a fish swimming from the top usually I might be lying a lot but usually this kind of stays a little bit more stable and then the rest of the body is the one that kind of shovels around or I don't know what the word is swims basically so I'm gonna put my my first one here so this is what's gonna basically drive most of this part and is the one bone that's gonna move the whole fish basically and then I'm just gonna extrude a little bit more a few bones extra I'm just gonna go like this and subdivide it and go here and add a little bit more cuts that way have more bones to actually work with and the fish can be deformed by that by this same thing if I go here and select individual origins you can see that if I select them they give me like a nice curvature which is basically what I want so with this I can already kind of shape my fish to do like some swimming of sorts probably it would be more interesting if I go and do something like that as well but we'll leave that to the physics we might not even achieve that so much but hey it's gonna look decent enough like if you put it in the background of your short film like this and you see a bunch of fishes they're gonna look good believe me so now that we got this we're just gonna bind this fish to the bones which are super easy to do just select the fish select the armature ctrl p and then automatic weights basically what this did it added to the arm to the mesh it added a deform and it also went and created weights for each of the bones we could rename these bones but we're not gonna do it because it's just a simple rig and that we don't need to name them basically but we could if we were professionals we would so you can see now that I get like a fishy fish that deforms magnificently mostly with this fins coming out and everything that's basically because the way it was built it's not the most proper way it's a bunch of planes which makes it incredibly light and I could go in and start weighting them to look better but I don't care because again it's gonna it's gonna be from really far and if I would be doing this for production for sure but in this case we just want to get the effect going on so we've got this fish we've got our main bone that moves around and we just need some dynamics here for driving the rest of the fish so for that we're just gonna create a little cage and this cube we're gonna reset its position we're gonna make it the size of the fish I'm not even sure if this step is really needed the making it the size and everything like that a fit but I thought maybe if I do it something like this we'll more or less have a better idea of how the physics would be more accurate because it's based on the fact that this here is moving this cube but what we're dragging is over here I don't know I just came up with that idea in my head and it kind of stuck and then I was like all right so nobody's gonna say no if somebody says I might change it and do another tutorial on it but so far so good so I got my cube I'm gonna subdivide this that's why I keep a mouse around because subdividing stuff with the tablet is ******* impossible in this ---- and now I am going to apply some physics so also I want to make this cube not be in the way all the time so I just go here to the objects and you can see this my my properties are all scrambled because now they're in three columns who knows why so I'll just go hit in front obviously it's not the one that I wanted I wanted this one wire and nothing's happening obviously because I'm in wireframe so I should be looked at or something like that now this cube is wireframe weirdly enough if I'm wireframe and this is set to wire I should see the fish which I'm not seeing I'm gonna complain about that but anyways so now we got this so this cube again is the one that's gonna have some cloth so I'm gonna just add a little bit of cloth here one cloth and I'm gonna press play oh ---- it's falling so first thing I need to do is make sure that it stays with the bone so how do I do this first of all for it to stay with the bone in fact the first thing that's gonna we have to do is make part of this be cloth and part of this not be cloth so for that I'm just gonna go weight paint I'm gonna go back to have it not be something transparent wireframey and I'm just gonna use this gradient down here which is really cool and put the strength to one and make it linear should be fine exactly and we're gonna look through an orthographic view so everything gets painted in the same direction and with the same sort of amounts and I'm just gonna do something like this maybe like that there we go so this is influence one and this is influence zero and this is all of the influences in between so what this will do when we go back to our cloth settings basically is that I'm gonna tell it to pin to that group and I should have named that group so I'm just gonna do it now oh there we go so this is cloth clothness pinning with the two ends right so what this will do basically is will tell blender where to pin it so the the red part that we were seeing before is pinned on one which means that part will not move no matter what you do meaning with the cloth and the zero is the one that's gonna be very clothy and and that's gonna fall so if I play again as you can see I pinned it maybe even too much so maybe we can tone this down a little bit so I'll just go here and then go to my cloth and see if we can maybe instead of the doing what we were doing before you can just assign maybe remove some weight I'm not sure how this works remove the selected vertices no we don't want that we just want to go to weight paint and then maybe there's a way to just add less weights to everything I'm not sure this is this is tricky ---- huh anyways just just let's continue so because now we have um the the falling part right and if I play and start moving this around nothing happens but if I parent from this one to the bone control p but in this case go bone you'll see that it moves with it and if I press play oh it drives it it's shaky I think we don't need to lower the amount I think it might be kind of all right so it's working and we got this simple setup that makes our cloth work now what do we do is we could try and drive the fish directly with this mesh we could um and wouldn't be very hard at all actually the only thing I would need to do basically is push this up so all of the vertices are in and then again now I get this and so now I'll just select the the fish even turn off the armature because this is another way just just so you know that it exists and use mesh deform and select cube and then bind now that it's binding bind dead not yet it's taking a long time but that's why I don't like it because for once takes a long time now you see the fish should be moving with this stuff I'm just gonna turn on the armature maybe that works maybe it moves now with bone yeah so this works and works pretty well pretty damn well um the only the only problem for me for me with this is as you can see it's kind of stretchy in some ways um and makes it not so cool in that in that sense and in the other problem is um it's just deforming the mesh which could be easily heavy and finally the bigger problem here is that we're not moving bones and because we're not moving bones we cannot turn this into actual animation like we cannot bake it to curves and then modify it if we needed to so makes it really like for the one trick and and that's it and that's not as useful so instead of using this bullshit I'm just gonna delete that and I'm just going to select my cloth grab the last face group it and create a new group called left back face and then I'll select this this bone and select this object this bone last ctrl shift c and I go dump track and dump track should be working but we need to assign a vertex and this is something that blew my mind I've never seen this anywhere else before you can constraint something to a freaking face or or group of vertices basically which is really cool so I'll do the same with all of these other dudes by just going pose constraint copy constraints to selected so all of them have the same constraint now and as you can see what's going on now is that this face is driving these bones but because but because they're all pointing at the same place it's a little bit stiff so what we'll do about this is I'll just lower the influences and then 0.75 here and then select this one 0.5 and then 0.25 bam and now play and this looks way more nicer so we're ready now what do I have to do I'll just grab the animation that you saw at the not this one clearly this one there we go and you can see the dynamics of the the cloth are driving the bones and it works pretty decently honestly and because it's dynamic and because it's cloth I can just like change my preset and it will to some extent change how it looks the final result you see also I have to say the reason I use damped track because I figured out I have never seen I've never seen anybody explain what the **** this is but basically with the regular track 2 constraint you have to specify an axis and it's easy for it to flip when it's in not like upside down like when it's upside down or something or doing some weird rotations and this one kind of worked out of the box and you don't need to specify anything else but what to look at so it's super easy to set up super quick and works like a charm so as I was saying before if now I wanted to modify the animation on the tail but what I got I like and I want to make it like change stuff by hand I could just go and press S3 bake action let's just write bake and then find the one that says NLA bake action and tell it to clear the constraints first so it will delete those constraints override the current action that way it will add these keyframes to the current action because in this case I do have some animation information in that bone which I want to keep and visual keying in this case maybe it's not that necessary so but let's just keep it there and only the selected bones just hit okay and as you can see now I got my bones animation there BAM it's that easy I actually could also bake first the simulation so then I get exactly what I was looking at so I'll do this 45 right bake BAM so now I know exactly that that is what I should get when I bake my action and then three BAM BAM BAM done and now I don't have constraints in those bones so whenever I want to change something I can just go here write x quaternions I hate this ---- um quaternions and then now you see for instance this part where it bends a lot there and then it bends it bends to the other side I could just like grab those those here turn on my my proportional editing even just like select one or like one here turn on my proportional editing make it really big because by default I don't know why it's so small super idiot and you see I can fix this and make it not go so much down or in fact if I use this maybe it's a little bit more you know what I mean so you can you can play around with this stuff and fix it and change it and make it more crappy if you want done I'm an expert on that part making it more crappy so there you go you fish with a dynamic tail hope you enjoyed hope you learned something remember to follow me to subscribe to this tutorial to check out lollipopman.com for further tutorials there's more reading stuff with animated gifs there's my friend Omari who is a lighter at the frame store in Montreal and who's doing a monthly review or interview about a special pieces that have impressive lighting which is really really cool so I urge you to check that out and that's it see you in the next one