Motorcycle Tire Modeling Using Deformers

hey guys in this tutorial I'm going to try doing something a little bit different we're going to do a topic based modeling exercise where I'm going to show you guys how to model a motorcycle tire like this one so there's a couple of things that make this motorcycle tire special and one of them is that it's actually parametric let me give you a sneak peak of what I mean the tire is actually created using a bend deformer and you can basically unwrap the tire and wrap it back up so we're going to go over the calculations necessary to get that bend deformer to play ball we're also going to look at how you can achieve some pretty stunning surface topology using this technique now we're not going to create a tire looking like this one we're going to create a tire for the Razorback bike model that I've been working on because right now I just have some low-polygon proxy objects for the tires instead of doing this tutorial as part of the Razorback series I'm breaking it out so it can be used on its own the first thing I did was copied this sort of low polygon proxy object into a new file so if I go to my file here I can see that I just have this front tire it's made of a lathe NURBS object with a simple spline as the has the profile and it does the job if you have a motorcycle that's going to be seen from this far away or if you're going to be using texture maps for the treads on the tire now for the Razorback I wanted to create sort of dual-sport treads for the tires so I'm certain this would be the right type of tire for this type of bike but I think it might be and this is some reference material that I found you can see that it's a really chunky design of tire and it's not quite like a motocross tire but it's not quite slick and smooth like a sport bike tire it's somewhere in between and I think that's the characteristic we want for the Razorback now we know that motorcycle tires are tricky to model because they curve in two dimensions at once in the real world when they make one they just create a mold and then they start injecting it and as long as the mold is perfect the rubber flows into all of the cavities and it's fine but in 3d we need to come up with some clever methods to achieve similar results so we're going to be looking at how to do that here's how we start the most important thing is that your center point of your tire is pretty well-defined because we're going to be using that a little bit the next thing is the process so you saw me unwrap that other tire in the other file and it sort of gives you a hint as how we're going to do this we're going to take a straight piece of tire and wrap it around in a circle so what we need first is that straight piece of tire so to create that let's create a plane I'm going to leave it as a editable object for now but I'm going to reduce the number of segments to maybe 10 by 10 from the top view I'm going to scale it down until it's roughly the same width as the tire now we can see that the plane is centered with the tire which it shares the same coordinates but what we're going to do now is we are going to push it up to the outside surface of the tire so imagine we wanted to wrap a untreated tire with wrapping paper this is how we'd start we'd start with one square of paper and we'd put it right on the surface of it so once we've got that in place we're a lot closer to the end result but if we're going to stretch this piece of tread all the way around we're going to need to make it a lot longer like this or we're going to need to have more than one sort of a replicated sequence of them now because tires have repeating geometry a replicated sequence seems like the right choice so focusing on the front tire right here we're going to just look at a section of tire right there and we see that maybe we can create it using using sort of an offset principle so you can see here that we can sort of draw a chevron shape and it kind of works so that's going to be a little tricky but we'll try it anyway but the main thing to remember is that the sliver of tie are we dealing with hair is quite small so we're thinking maybe Italy quite squat something like that and we can adjust the number of segments in the plane accordingly so that it looks a little more uniform okay so the next step is to try to figure out a little bit of math I was a I was never one for math in high school but the math we're going to be using here is basically circle math so circumference diameter we're going to be dealing with PI a little bit what we need is we need a bend deformer all right it starts off with just a big box so we're going to scale that down and move it up to the top here now when we increase the bend strength of this bend deformer it bends towards us right now so we can rotate the bend deformer where we can change the angle here so let's change the angle to 90 degrees and we can also rotate the bend deformer like this so that it starts it so the 12 o'clock position where we are seems to work so far now we're going to want this bend deformer to go 360 degrees like this but now it gets kind of tricky because the center point of the bend deformer is all the way over here we sort of want the bend deformer to have its center point here and it seems like a really tricky thing to measure I mean measuring it is one thing but it needs to be perfect for what we're doing here so that's where the math comes in if we reduce the bend amount just so it's just a little bit and we can sort of look at the coordinates a little bit better we have the Y length we have the X or the width and we have the Z the depth so for this example we're going to be using the deform er in the unlimited mode so it doesn't really matter how big and chunky it is but it helps to visualize it so we're going to do a sliver like this let's use round numbers so 1.5 for the thickness let's go to the top view it looks like I moved it let's make sure it's still at the center of the scene and for the width let's make sure it encompasses most of the tire again it's just for proportion and then here's the tricky one the length like how long does it need to be if we know it's going to be 360 degrees around we know it has to be pretty long but it gets so difficult to position it at this point so here's how we do it let me just go to the side view so maybe I can sketch it out a little bit better we have a two dimensions that we can work with right now we have the you have the radius of the tire and we have the center point which means we have this dimension and then we have the circumference so we actually have enough to figure out where to position this bend deformer we show you what I mean the position of the deform er in this view so the Y Z the Y position is really easy to figure out it just needs to be the same as that first segment of tire that we created up here so this plane is currently at eleven point five nine three inches so that means that the bend deformer needs to be at that same height the reason is we kind of wanted to start like that up here on the surface so what we can do is we can set the Y position to the same value eleven point five nine three I just pasted it in the next thing we need to figure out is how long is that circle how long does it need to be to fit our tire perfectly so to figure that out we can apply PI to the diameter of this circle we know the radius of the circle eleven point five nine three from the center to the edge so the diameter is eleven point five nine three times two and if my math doesn't fail me I believe the circumference in other words the Y length should be eleven point five nine three times two times pi so let's see what that gives us I hope I'm right here so eleven point five nine three times two gives us twenty three point one eight six and if we then just say x 3.14159 it gives us this big circle so I think that value looks correct so what we've done is we've actually made it so it's the right size now it doesn't look like it's the right size but if we go from the side view we can see that that's actually because of this keep Y axis length option when this is turned off it sort of bends on the outside of itself when you turn this on it bends more on the center point so we can see that we've actually gotten the circumference to be perfect now we've kind of gotten the Y or Z positioning here but we can get that exact as well if we unwrap the bend deformer we can see that laid out straight it's going to be just the circumference so that means that if the circumference is seventy two point eight four one units and this is the center of the scene then it probably needs to be half of seventy two point eight four one and it'll be the right distance away so if we set it back to 360 degrees of Bend and then we set the this is the Z position you can see the Z position moving down there the Z position is going to be seventy two point eight four one divided by two and that gives us the perfect positioning for the bend deformer so now we can take this object duplicate it around the tire and be confident that it's going to be bent at the perfect angle so the next step is going to be duplicating this plane forward now it seems like a good job for a more graph cloner so let's use that under the more graph menu I'm just going to grab a cloner now by default the cloner starts cloning objects from its center so if we put the plane into the cloner we see that the cloner has started down here at the bottom and it started to clone this object upwards not really what we want so i'm going to ungroup that and the plane is up here at eleven point five nine three inches so I'm going to move the cloner up to the exact same location now the clones go upwards from there but we don't want them to go up we want our clones to go forward on the z-axis not on the y so we can enter zero for the value on the Y and for the value on the Z mm-hm we need to calculate this pretty carefully but before we do that let's just do it roughly so it looks like we can do roughly one point four eight eight inches and then in the corner we can just increase the number of clones so let's see roughly how many we need if we create a null object and place the cloner in there along with the bend it's going to influence it so now we can see our cloner is bending along the wheel the tire and we can sort of increase the number of clones until we're almost at the other end and this is where we can start to play with the values a little bit so there's two ways to do this one way is just sort of interactively playing with it until it lines up the other way is by actually calculating the length of each clone and the number of clones required I'm just going to do it the easy way so the easy way is you take the plane and we know how big it is on this dimension let's set it to 1.6 and so we know the cloner needs to be 1.6 units until the next clone and that gives us the right the right spacing but there is a little bit of overlapping happening here the clones are coming right back around and hitting themselves again so to fix that the easiest thing to do is just to grab the cloner which has an origin of right here and just scale it so as we scale it down we can see that it basically changes the length and the width but more importantly the length now what we're going to do is we're going to get it as close as possible and then we're going to go down to the size here and start tweaking the size so we can go to point 4 got a little bit closer let's try point 8 4 it looks like it's almost there let's go to point eight three yeah so it looks like point eight four gets us right up against the edge of it and we're still not perfectly lined up there's a little bit of a gap but that's okay because we have gaps everywhere each one of these objects is not joined to its neighbor yet let's see how we can actually do that if we go here to where we know there's a gap we can actually see it let me change my view clipping to small so we can zoom in smart we can actually see the gap the way we fix this is with a connect object so you've seen me use the connect object before I'm just going to say connect and I'm going to drop this null object in there so right there it sort of merged all of these objects into one so we can see that the on the object underneath is poking through a little bit let's just hide it for now so what we have now is we basically have a parametric ribbon we have an object that goes right around and it doesn't have any seams or any gaps in it the foam shading should be perfect all the way around it because all the objects are joined I think if we turn off the connect object you might be able to see it might be difficult to see what the video compression but there are steps you can see each object once we turn on the connect object it becomes one continuous strip so we basically created a parametric tube and you're probably wondering why all the trouble because cinema 4d comes with these built-in it's just the cylinder but we can do something with this that we can't do with a cylinder which is that we can sort of tweak the number of segments we need and I'm just going to create something uniform looking and if I were to convert this to an editable object and editable plane we can see now that we can sort of select patterns in here and extrude it and it extrudes all of them at once and so this is getting us well on our way to creating a spherical City a cylindrical City or a motorcycle tire so now might be a good time to look at the reference material just going to undo a little bit and if we look right here we can see the for the front tire which is the one we're working on we can we can sort of see that there's a chevron shape but it's sort of an sort of an offset Chevron shape let me see if I can illustrate what I'm trying to show it's not simply a pointy thing it's a pointy thing like that but the repeating pattern we have should be able to handle that so let's start off by trying to create that shape if I go to the top view turn off the bend turn off the corner I left it just a plane we should actually be able to warp this object into that shape so I'm just going to use a free-form de forma because I think it'll do this a little bit more quickly than if I did it by hand so I'm just going to scale my freeform to form or until it's basically the size it needs to be and I'm going to place it as a child of the plane and then I can grab these points on the edge and nothing it's probably not lined up in the view so I'm going to place it over the object and this time when I use my rectangular selection I'm going to make sure it's selecting all visible elements and we scale it down it looks like it's sort of bending it let's try more more segments so let's do you know what this is probably just going to be easier to do by hand let me do it by hand so what we want is we want the plane to have enough subdivision so that we have one in the center so an even number and I just I'm trying to strike a balance between not too many segments and not too few because we are converting it to an editable object at this point so we just press C and then whoops 14 so you press C and then what we can do is we can sort of see let's grab these two rows of points sweep them back let's take all the rest sweep them back as well and you can kind of see what I'm doing I'm just sort of creating the chevron shape but at a certain point I think one side of the chevron needs to go further back than the other so I'm just trying to figure out what it would look like so with one side going a little further back than the other and this side still needs to sweep back just not as far we can sort of see what's happening with our cloner our clone is replicating that quite nicely because notice that if I were to move these points forward it moves forward on all of them so it just sort of stays with it it's really nice effect and so now that we have this chevron sort of shape let's go back here so it looks like we want this part of the Chevron's come all the way up and hit the edge and this other part starts kind of late and I'm trying to figure out it looks like it does that for the entire duration of the tire or does it what does it actually have something here that I'm not seeing I think the shape is playing tricks on my eyes but let's just see how it works out okay so it wants these polygons to come all the way up and hit there so that's not going to work with the pattern that I have right here so we'll just improvise and do a similar looking pattern so I think what we need is we need something like something like that in terms of our mesh I'm not immediately certain how to create that so we'll just do something similar looking this is really bugging me though so moving on we can bend this object around and then we can do the extrusion so let's do that sort of going to figure out what it's going to look like so we can do a block of stuff there and then another block down there or let's let's try this you have an idea what if we were to select all these faces in this plane and use the clone command to make one clone and then move that forward so we now have twice the area and that's going to mean that we need half as many clones so we're only going to need 24 to cover the same area and I'm just going to turn the corner off let's sort of select the loop of edges here this one on that one and then do you select all the other edges I'm just going to use the stitching so tool to patch this back up it's usually a lot of trial and error when creating a tire like this at least in my experience so we can do MP to get the stitch in so then we just stitch those edges together now we do have a different offset for our cloner notice even though I have half as many clones it's not going all the way around it's because the clones aren't the right distance apart but if I were to select this it'll give us the length of it which is three point zero four six at the size and hopefully if I enter that it gives us the correct distance not quite but we can just scale it down to fix it so I'm just going to scale on the corner a little bit and then we get this double line right there and we can go back to the size of the corner so point one three point one one one zero seventy five point nine point eight that's not right looks like something might be doubling up no I think we got it let's turn off the connect object making things confusing looking so grab our cloner we just want to change the size so seventy four point nine point c seventy five point five think our increment is too big so seventy five point four five right there we're almost there seventy five point zero seven five zero seven seven zero seven eight okay that's close enough we turn on the connect object it just sort of fixes it for us okay so the whole point of that is that now we have more material to play with when creating these treads so what we can do is create one row of tread that looks like that and the other row will come in down here making the opposite pattern and hopefully it looks good so I'm going to start off with this bit selected right here and what I'd like to do is an extrude inner so with these polygons selected I can just do an extrude inner and remember that this distance right here is going to be half of the gap between the treads so it's actually a pretty big gap on this tire so let's make sure we have a nice big gap okay and let's see these edges are still a little bit wobbly so I can I can probably come in here and just make sure those are nice and straight just make sure to select all the points and move them as a single unit because if you don't it won't line up correctly any longer okay so I'm just going to extrude inner apply we get that now I just need to do the other parts so I'm going to select these polygons are going to be another big chunk extrude inner apply and then I'm going to select the opposite down here so it looks like I went over two units one two and then I can do extrude inner again apply and right here select this last group of polygons and one more time to the extrude inner so what we have now is a is four groups of polygons that we can select and sort of extrude the easiest to select these might be with a loop selection so we can select the gutters in between and then we just invert the selection and we got all of our islands that we created so now that we have these Islands created you can turn our bend and our cloner and our connect object back on see we have a lot more geometry now and we can just do an extrude operation so just to see how much we need takes treated quite a bit so just drag that up and we get our nice thick looking tread with this sort of chevron shape it's not quite the same pattern we add here but I'm sure we can achieve that if you just spend enough time creating the sort of prototype shape for the tread using sort of a wireframe mesh like this and so once this part is created we can just start to go nuts beveling it and smoothing it out and stuff one place you're probably going to want to bevel it is down here and this sort of canyons that it's created just going to select the loop of edges around each of these so it looks like it's all four and then just using a simple bevel just going to do the bevel operation now remember not to bevel too far because otherwise the connect object is going to merge the points in an undesirable way but you can fix that by just reducing the tolerance of this so I reduced it to 0.2 9.19 it looks like 0.19 is small enough that it doesn't affect our bevel and we can then do the same thing with the top of the tire so just like that and we can even come in here and do the central spine down here so that would involve a loop selection maybe a greedy search will do it not quite I might have to just select it in the top view so we can just select all those edges that run down the middle and then we can bevel it to get a nice rounded part on the front there and you know you can go through and add polish to whatever aspects of this tread pattern you want you can go as far as using the brush tool and part of it so now that we have the tread pattern there's still a couple other things to do let's turn back on the front tire or proxy and immediately we can see well it's just straight across but that's not what a motorcycle tire is like it curves down at the sides it's pretty easy to fix so I'm just going to call this 360 then and we're going to create another bend deformer I'm going to go from the front view and scale this to four more down a bit now if we increase the strength on this deform er let's say 45 degrees we can see that if we rotate it like this 90 degrees it's sort of starting to look correct and we can just sort of scale it down just kind of looking at it and you can see it's almost near the center there let make it perfectly at the center I think we can use the same trick where we take its dimension and then we make that it's exposition divided by two so it's perfectly on the center right there and if we wanted to maintain it perfectly on the center what we could do is we could group it ungroup it so we have a null at the exact spot where it is and then zero on the x-axis and put the bend back into it and then we can just scale from the null object and it's scaling using that coordinate system so I'm going to move the bend deformer down to right there right on the surface of the tire and we're going to change its X dimension just so it's a little bit more representative of what it's doing and we can then take this bend deformer I'm going to work with the null as well no need to ungroup it for it to actually work but I'm going to leave the null object in the hierarchy so now we take our bend the former we can see that if we increase the strength we get the tire to curve downwards now we can make it curve the other side by choosing unlimited as the mode so it curves both sides now and we can sort of see how it needs to curve now this is one of those cases where we don't want to choose keep Y axis length because we actually do want it to sort of stretch the tire around the edges even though we're doing our best to stretch it it's not really representative like we're but look at how far the bend deformer is curling for these tires so what I'm going to do is I'm going to put the bend deformer back into the null and scale it down a little bit so it's closer to the edge of the tire right there let's see how that does okay so that's a much better representation of how the bend is working and even though we even though we bent it all the way down and it's being stretched on the edge and everything it still isn't going down far enough right here and to fix that which we can just scale the source object so we can take this object and scale it on the x-axis we can safely do that without messing up the cloner and we just scale it until it goes down to the right amount like right there and then we can go to our bend the former again and we can just make sure that's bending the right amount and there we go we have like our curved profile of our motorcycle tire so when we look at it just sort of an isolated view I mean it's not the most attractive looking tread pattern because you didn't spend a whole lot of time on that but the idea is that you can make this segment of the tire whatever you want like for instance let's make this tread pattern a little more interesting by smearing it around a little bit so I think this should work I hope it works as long as we keep the boundary of the shape intact we should be able to smear the inside of it to get a little creative flair so I'm going to use a lasso selection mm maybe there's more efficient way to select let's do a loop selection around the edge now cuz it's just gonna well maybe we can do this thinking out loud now if I select all of the loops we may be able to come in here and deselect the inside part of these loops like that and then use the fill selection tool to select the inside there we go so this sort of guarantees that we're not going to tamper with the edges we can even go a little bit further by just deselecting some of these near the edge so we can be pretty sure we're not going to mess with them and what we can do from here is use the brush tool to sort of smear things around so if I use the brush tool a smaller radius and we use the smear mode so you can sort of smear the treads around sort of give it more of a stylized look and it does sort of make it a little more interesting but I just wanted to give you the idea the best way to handle this is to do what I did on this wheel which is to actually take the time to sketch out the first piece you can see here that I did not use a cloner I used instances you can do that too but you can see here I really took care to make sure that I was really getting the right pattern here this is a pretty complicated pattern but it does repeat you can see right up here where it ends it picks right back up and it looks really complicated here but think about this with just square grooves because that's how it started off and then of course I did the and then I beveled the edges and did the hypernurbs and all that other stuff and it also shows how you can bring the edges down like this so let's do that in the other file so just to make this look a little bit better let's go back to when we had the top parts selected at the tops of the islands I'm just going to do the old extrude inner trick so this foam shading is looking really smooth and kind of weird so if we have all the tops of the islands selected and we just did an extrude inner you can see kind of makes it a bit better even though something weird is happening here let's just do a little extrude inner and then a normal scale maybe that'll work yeah there we go so I can take my time and do this better I'm just I'm just trying not to make the screencast longer than it needs to be so we have sort of this shape of these treads going right to the edge and the tread coming up in the front and center and curving I mean you can put this in a hypernurbs after if you want but as you can see it's pretty smooth nice and curved on both dimensions so getting the sidewalls is super easy all you do is using the rectangular selection tool you just select the edges on both far sides once you have those edges you can use the scale tool or any sort of extrusion tool to bring those edges out like that and you can see as I do that it's sort of bringing them down over there on the side of the tire so the reason it's coming out at a strange angle like that is because it is being bent so I'm just going to bring it down like this and then I'm going to scale again to get sort of the majority of the sidewall and once I have this sidewall apart I can just move it down and it sucks in so if I put the front our proxy back in place we sort of have something to gauge against and you can see here that I'm sort of bringing it in and out I'm going to turn on wireframe mode so we can see and you basically have two controls at this point you can scale them in and out or you can move them up and down and each of them kind of do the same thing because again you're bending the side of the tire down so you have to take that into account the other thing we can do is subdivide these walls once there once they're sort of the correct size hair as you can see I have them at sort of the correct size the reason is because most motorcycle tires have a slight concave or convex shape right here so we can just use the knife tool if you tap and release shift it sticks and you can actually set that to whatever percent you want like 50% then you click and it cuts it so we can just do that on both sides tap shift and release set that to 50% and then click and then you can select these two loops of edges and we can scale those and that sort of creates either concave or convex look right there to sort of match what we originally had with this tire so if I completely turn off our reference tire you can see here that on new tire is sort of a I'm just trying to there we go display is shaded our new tire has the sidewall has these curved treads and you know we can really easily adjust those if we need it to you can also come in here and do things like soften the edge so let's see if I wanted to turn off all these generators and if I just wanted to look at my segments of tire by itself I can use the live selection tool to select just these points along the edge let's do it right here as well I'm only going to do it to ya might be lazy it's a long video already I'll do it to both sides so then I can just take my brush tool in smooth mode maybe it's 2 percent let's sort of start to smooth these edges out if I wanted to do this to both sides at the same time what I would do is select the points on the other side as well so go back to my live selection tool and just run along the edge here selecting these points and this is kind of a hack but it works is to make your brush really big so I'm going to use the brush tool maybe increase the percent to 10 with the radius let's make that 50 thousand and what happens is you no longer see the radius of the brush because it's huge but if you click here in the center you pretty much affect both sides at the same time probably see how that works so if I turn all the generators back on you can see that happening in real time and you can sort of just see the edge of the tire getting a little bit smoother and that's one way to do it the edge of the tire comes down a lot more smoothly now and if we wanted to make that more drastic we can just grow the selection and repeat the operation but in general and that's how you parametrically make a tire like this for the Razorback bag I'm probably going to remodel this tire with some tread that more closely matches this because I really like how these uh mezcla tires look and yeah I hope you guys enjoyed this video it's a little bit different than the ones I normally do it's not really like a random 5 minute tip on its own and sort of related to a project and a specific task but I really hope that you guys enjoyed this if you did enjoy it let me know if you want to see more stuff like this I'd love to know if it was a little too long and boring and I should probably stick to the other stuff I'd be interested in knowing that too so until next time see you

Channel: Jamie Hamel-Smith

Views: 65,562

Keywords: Cinema 4D, Motorcycle, MoGraph, Cloner, Deformer, C4D, Tire, Treads, Modeling, 3D Modeling

Id: dktlSFUBTEA

Length: 47min 51sec (2871 seconds)

Published: Thu Jan 31 2013