Topology With T-Splines In Fusion 360

all right I guess we're doing this topology with T splines in fusion 360 this is a video about topology essentially how do we think through and plan out the construction of T spline geometry to make something look the way we intend well look at some semi practical examples and hopefully by the end we'll at least have an understanding that topology is a term that exists anyway let's start by making something this may seem like review for a few seconds but it's really just two T things up so let's hit create form and we'll make something simple we can start with a basic plane it doesn't really matter where it is at this point so that's fine and to make it even simpler we'll make this one by one face ok so now we have a t spline body in the sculpt environment so edit form will be our main tool with t splines we can move around faces edges vertices and if you hold alt or option well moving either a face or an edge we can build on this geometry but let's pause for a moment because there's something big happening here and if you're familiar with Polydor subdivision modeling you probably already know where we're going with this we've done essentially the same command on two different elements of the geometry one on a face one on an edge and these two ways seem similar but they are so fundamentally different an approach that they split creating things with T splines into two separate modeling strategies one where we create geometry by extruding faces some call this box modeling because the underlying geometry looks like it's made from boxes and the other we can call edge modeling where we extrude individual faces from edges it's important to note here that none of these strategies are right or wrong and both can reach the same result in the end we can also mix the two but they require different ways of thinking if I were to put difficulty levels on these strategies edge modeling would be medium and box modeling would be both easy and hard at the same time this is because with box modeling it's very easy to make something perhaps one of the easiest modeling methods in all of fusion but what are we making with it the forms to start out with our very blobby and undefined and they get definition we now have to go in there with various tools and edit how that underlying mesh is defined this can be quite difficult on complex models with edge modeling on the other hand we try to create that definition from the very beginning and in my opinion that makes it easier to get refined surfaces that look the way we want them to so for that reason we'll focus mostly on edge modeling in this video and once we get more comfortable we can start using box modeling as a shortcut for quickly blocking out forms and now we move on to the word of the day topology to understand sculpting with T splines is to understand the idea of topology for T spline bodies this is essentially the flow of faces and edges on a model by changing this flow we can change how the resulting model behaves and since different flows give different results we need to figure out the ideal ways of creating topologies that give us clean resulting surfaces that match our design intent some terms that might help us out a bit here are edge loops face loops and rings in the context of fusion 360 these our selection modifiers for selecting continuous groups of edges or faces you can find these all in the Edit form toolbox but for this video we don't need to worry about any of these as buttons it's more important to understand these terms in the context of how they define the model so an edge loop looks like this it's a continuous connected group of edges and similarly a face loop is a continuous connected group of faces and finally a ring looks like this these are the edges between faces in a face loop one thing to note here is that a face loop in a ring when we are referring to the topology of a model might be used interchangeably because you can't have one without the other so if you saw a couple of my other videos and heard ring around the detail or maybe saw poly modeling tutorial that mentions a ring you can make that defining ring by creating a face loop we'll get into this more as you start looking at examples so how does this apply to edge modeling and how do we start ring around the detail is something that I heard in an old 3dsmax tutorial that stuck with me but let's change it up a bit to make it a little bit more clear maybe when we are starting a t-spline model we want to first determine the defining edges and features on our model then create face loops that follow those features for those face loops we'll want to determine an appropriate density of faces for a model that's roughly evenly spaced we can adjust the spacing in certain parts of the model to create less or more curvature acceleration and we'll take those face loops and fill in the gaps to complete the form okay let's look at this brush in a little more detail this is just some random brush I haven't met kitchen we can break down how this is put together the first step is to figure out where the defining detail areas are on the model and there are only a few there's an elliptical profile here on the bottom and there's a sharp edge that runs around the front that blends out around here and it'll be helpful for us to also call out the centerline here as well so those are the details that are going to drive our topology now we need to define the face loops that I'll create those details let's start with the edge at the front for now let's assume that this will be a crease edge that will end up fitting and we'll look at another way to do this later so we need to define this edge for this will create two faced loops one on either side of the edge so here and here then we'll need another face loop to define the ellipse on the bottom for now we won't worry about the flat surface on the bottom there are many ways we can take care of that later we can also assume that we can take these face loops and continue them through to form the back of the handle these are going to be our defining face loops now we can figure out how this gets broken up into individual faces to do this we can ask a couple questions where the details exist or stop like where the filler that edge will terminate and where will face loops change direction like this point at the front of the brush essentially what are we defining and where will we need to have higher densities in order to get the detail we need a good starting point is to think about defining this with this low density of a mesh it's possible to define the detail we need it's good to keep in mind here that lower density meshes are usually preferred because they're easier to manage and keeping things roughly evenly spaced is also usually preferred you want the curvature to change so in our case the turning point of this front note section and the end point of this creased edge will be good places to start is it going to be one edge loop that runs around the center line and now we can see roughly with the spacing of these faces and edges want to be if we think about even spacing we can finish defining this creased edge this will be the spacing that will drive the rest of the model we can continue these phase soups all the way to the back of the handle there's some tighter curvature at the transition to the handle so we may want to adjust the tension in that area by making the spacing a little closer together we can use a spacing we've defined to also create the face loop around the elliptical profile and with that we have all the defining face loops on the model now we just weld things together if needed and fill the gaps to finish defining the topology and don't forget that this will be a creased edge for now on the bottom we could take several approaches we could create another face loop if there were detail here that we needed to worry about you could also leave it open as is and use patch tools to define a perfectly flat surface well cover a little on that approach later for now we can take the simplest approach and just fill faces across the gap a quick way to do this is with the bridge tool and that is the main body of the brush before any details well we're talking about tools in the sculpt environment there are several tools for editing geometry and if we have a hard time figuring out what to use when there's an easy way to break down the tool set on a basic level all of these tools do one of three things we are either creating faces creating edges within faces or welding and combining edges or vertices that said we can do almost all the t spline modeling tasks with only three of these tools edit form insert point and weld vertices I found these to be the base level tools with the most control for doing almost everything the other tools offer shortcuts for making specific tasks faster like bridging gaps for example if we understand these core tools and is easy to understand the rest just by reading the descriptions just a quick note on mirroring there are two types duplicate an internal I only call this out because the default tool in two Bar is mirror internal but everything we'll look at in this video is done with mirror duplicate internal is good if the object you're working with already has symmetry like a box for example and duplicate it's good if you want to start by modeling one side then create a mirrored copy of that side which is what we're doing with the models in this video one of the things I like most about T splines is the ability to create variations and surface transitions to determine which it's best so for example if we don't like how this fileted edge is terminating we can do a couple more options to see which it's best we can make a copy of our original then we can go in here and change the topology we defined there's an initial bevel we need to do to replace the fill it but we need to control how this flows into the rest of the model there are many ways to do this but for me insert point and weld vertices are the main tools this allows us to quickly change the flow and now instead of relying on fill Edenic creased edge you now have much more control over how the blend is constructed in this case instead of coming to a sharp point it's a soft blend you need to be mindful of how the new loops we are adding flow with the rest of the model generally we should be thinking about how to make the edge and face loops as continuous as possible having breaks in the flow or inevitable but the lesser then we have the better the surface quality so here we can see the difference in the transition if we were surface modeling this it would take an entirely new construction of this area to make this type of change there are some common problems that can happen with t splines that many of us will run into so let's see how we can fix some of the work infusing ones if you use vertex selection in the Edit form you've probably encountered some extra handles that are otherwise not accessible for most things we do with T splines we shouldn't touch these they are useful especially when transitioning to other non t spline geometry but for a pure t spline model they tend to cause problems if you do happen to edit them you'll notice that the handles turn red to fix this while editing in vertex mode we can select all the vertices we want to relink and select link tangent handles another common issue happens when editing while in smooth display mode there will be problems in the surface even though the edges seem to be in the right spot switching over to box display mode can help us see all kinds of problems I'll often use this mode while defining the entire initial topology of a model box display mode will also help with giving proper spacing especially with a higher density mesh there are some unexpected things that can happen sometimes with t splines but there are a couple tools to fix these if they happen so let's look at this faucet real quick to see a couple of these issues and how to fix them if we look at this in box mode it looks like it should be fine I'll suggestive perhaps but fine but if we switch over to smooth display the result is not what we should expect so how do we fix this there's a repair body tool that highlights various problem areas like faces that are not for sighted heirs and intersections things like that and it has a couple simple tool to help fix them sometimes an auto repair will fix everything but this one is a little more tricky because fusion doesn't see it as an error but there is a hint for us that it's called out on the model on the bottom here it shows these faces as being three-sided but they aren't so what's going on here this is because it's treating this point as a key point t points are great and we'll look at them later but it isn't what we want here in the repair body tool we can convert to and from T points by simply clicking on that point in all honesty working with T points as want to use the repair body tool for most often so there's no more error with the geometry but it still doesn't seem quite right again the spacing on our base geometry seems fine but when viewing it in smooth mode the spacing seems off we can fix this by using the make uniform tool on the body problem solved this doesn't change the base mesh at all it only affects how it's interpolated honestly I don't know why this tool needs to exist I mean why is teeth spline body not uniform in the first place but at least there's a way to fix it oftentimes I'll run this command on all t spine bodies before leaving the sculpt environment just to be sure T for are a great way to terminate edge loops within geometry they are especially helpful when you want to step up or down in the resolution of the mesh like we're doing here on this faucet handle T points are often created automatically with T splines when adding edges within the geometry but as we saw before we can control this with a repair body tool now there's a general rule that with both poly or sub D modeling and T splines that they tend to favor four-sided phases going with three or five sometimes even more than five is more likely to give unfavorable results T points changes this rule here we have a face with five edges but because of how two points are interpolated the resultant surface is still clean if we change this back to a star point with a more traditional five edge face we can see how the result is not nearly as clean T points don't work for everything and as we saw before it's sometimes not the desired approach but it's one of the benefits over traditional poly or sub D modeling that's valuable to learn about as far as this video goes this is the only T point on any of these models the rest stick a more classic approach to loop terminations alright let's try making something a little more complicated I thought it'd be fun to make a creepy mask for Halloween it's not even remotely close to Halloween anymore but whatever the idea is to figure out the topology of a face then we can exaggerate some of the features to make it a little bit more Halloween II I am no expert at modeling faces so we'll quickly look at how this was done first then we'll look at a better topology and see how these things could have been done better if we go back to our approach we need to find the defining areas on our model if you need a starting reference you could use virtually any photo of yourself or someone else because once we have the base topology it's relatively easy to modify it into whatever we want so where are the details on here we can start with the eyes brow Ridge mouth nostrils cheeks and one more face loop that will define the outer edge of our mask there are some more loops that will radiate out from these then it's just a matter of filling the gaps being mindful of trying not to break the flow so this is what I came up with for the topology of a face but I'm not really in the business the modeling phases so we should look at another example before we go let's make this thing extra creepy by giving it teeth all right I don't remember where this model came from but they did a few things differently than I would probably try if I were to do this again it's a hair density mesh which I typically don't like to deal with but the flow of faces on this model are very well thought-out how they define the brow Ridge so that it loops around it also defines the bottom of the nose works really well here this seems to be a rather common technique from some of the resources online if we look at just the defining loops on this model we can see how deliberate they were with how the flow is laid out I didn't want to go into too much detail here because there are better resources out there for this topic if you want to learn more about modeling faces you can search for face topology and you will find many resources they will probably be for a 3d animation package like Mac's blender C 4d or any other but the core idea is the same you can apply the same thinking the same topology to a t spline model in fusion we can also import the unsub divided meshes into T splines within fusion which is what this model is it wasn't modeled in fusion it's an imported obj but it works just the same this means in theory that we can work with other external software or artists that use other tools and still have the ability to edit within fusion one approach that I use quite often with T splines is to mix it with other modeling methods within fusion technically it is possible to do nearly anything with T splines but it's often not the best tool for the job without no being too deep and new class a surfacing terminology one of the main drawbacks of T splines is that it's hard to keep good overall surface quality especially when we have complex topology with many driving loops for example if we wanted to make a proper round hole within a t-spline body we would have to consider how the topology of that hole transitions to the rest of the body this isn't particularly difficult if we have only one but what if there were multiple there are entire poly modeling tutorials dedicated to just showing you how to make holes in various topology layouts but we're in fusion 360 so why would we do this we have the ability to simply cut a perfect circle every time or any other shape for that matter it's this mixing of modeling methods for me is what makes t-splines inside fusion so powerful for concept models let's take this controller part for example t-splines by its very nature is more gestural in how it treats form so defining precise detail like these would take considerable time and still may not give clean surfaces instead what we can do is use T splines for one is particularly good at creating complex surfaces and use parametric modeling for all the details for this video I've only modeled the top of the controller but the same approach could continue to the bottom as well we won't delve too much into surface modeling here there are other resources for that but the general idea for this one is to over build then trim away the sections of detail like the top of the controller here or where the thumbsticks are and use various patch tools like loft to complete the form this would be much faster than trying to make it with T splines and gives a rather clean result I know this video doesn't go into enough detail for those just starting out with teeth blinds but hopefully can point toward what to look into in practice it may not seem like there are many resources out there for figuring out t spline topology and technically that may be true but once we start looking into Palio subdivision modeling tutorials there are tons of resources out there the core concept topology is the same among all of them whether it's 3ds max blender even gravity sketch now how the subdivision surface mode I mean sure there are some differences key points are a good example of this but there isn't much difference in how you think through a model now suddenly a six or so tutorials turns into thousands and most of them know a lot more than I do about topology I'll link a couple below that's just about the end for now hope it wasn't a complete waste of time so normally I'd put disclaimers at the beginning but I felt it made more sense here don't treat the things in this video as being absolute truths there's a lot of opinion built into some of these topics and it's quite likely that some of the things in this video are just wrong in fact I hope there's something in this video that frustrates somebody enough to make their own tutorial to be honest that's what actually spawned the initial idea for this video our collective knowledge on this topic is really only as good as the resources that are available for it and our ability to share our understanding with others that sounded a little preachy but I know that there are people out there who really know t-splines inside and out yet the resources still seem to be lacking I mean I'm excited to still be learning along with everyone else anyway call to arms over I guess I'll be spending this year on some projects and experiments this may or may not mean more videos I'm not sure if it does some might involve fusion but most probably won't so if you're subscribed I suspect you're probably here for the fusion stuff but hopefully you'll still find it relevant tuned interesting anyway thanks for sticking till the end

Channel: name notimportant

Views: 31,041

Keywords: Fusion 360, t-splines, topology

Id: BAQgvASaOPg

Length: 20min 48sec (1248 seconds)

Published: Sun Jan 26 2020