Merging two topologies using subdivision surfaces

in the next part of this modeling tutorial we're going to take a look at this component sort of the center of the model this has a challenging area we're going to return to the use of subdivision surfaces because it's really ideal at taking and merging these two different apologies even though it can be a bit of a challenge to figure that out we need to start off with the start file we need to extract geometry from the geometry we've already created using the direct polygon modeling approach and we're going to adapt some of it for subdivision purposes the resolution is too high here we're going to end up merging a lower resolution piece of geometry here and we need to sort of generally match them up in that sense let's come over here and turn this side off we don't need that and in edit mode I'm going to select this perimeter shift and D press the y key and we'll pull that out but then we're going to use these flat areas all the way down to the center point because I did put a loop here that is directly in half so we're just going to go to the halfway point since we can uh use symmetry but we need to remember that we have a boundary Loop that comes here and a boundary Loop that comes here and the curvature doesn't start until this Edge down so I'm going to hold the shift key and make sure that I'm selecting that press shift and D escape and then press the P key to separate that to become its own object now we're going to do the same thing over here in Edge mode I will select that press the P key and separate that also to become its own selection press the Tab Key to leave edit mode we're going to take both of these components and move out to the main scene collection and then we're going to turn off the face plate so let's let's come back in and sort of rename these I'm going to rename this to be just Center and this I'm going to rename to be profile so it's clear in the outliner what it is that we're doing so with this one selected let's come in and remove these extra Loops that we don't really need for this purpose we're going to put in new Loops that we need for what we're going to be doing but we don't want to start with those we just want to have the basic planer geometry is our starting point at this point to make it easier to differentiate this profile curve from what we're modeling let's come over and let's change this the wire color to random so that we can we can really differentiate the two that we have going on here and then we're going to select those two edges but we're going to switch over into vertex mode and having the vertices available to us visually is really going to help with this process if we switch over into the front view then those vertices will help us to find the resolution quite a bit we don't have the bridge Loops function available to us when we're in vertex mode but it is available up here under the edge menu so we're just going to do bridge Edge loops and then we need to start customizing it so the first thing that we want to do is put the number of cuts in let's just start with eight but one thing we want to be cognizant of is the fact that we can perform a symmetry operation because we're going to be doing some manual work up here and it would really be good to have a a point in the middle so for instance if we did nine that would be ideal to have a point symmetry point in the middle we may want to increase the resolution but let's take a look at that in a minute but we need to change this from blend path to blend surface in order to get that curvature in place uh let's come in now to the the smoothness and let's let's increase this up a little bit let's do 6 and I think that'll work pretty well so one thing that we want to do is get the vertices on the outside and we want to get the edge close to the profile and I think maybe we should bring it down 0 595 and I think that works pretty well again point on top and the center almost touching the line is kind of how we want to Define that now uh we've got a problem here because now we've got the point almost on the line and we've got the edge the center below the line so we're going to have to do some manual work here because this blue line was modeled with a perfect 90° Arc of a circle we need to go to a little bit of extra work to get that to happen but with the subdivision but I think we need to increase maybe the resolution just a little bit let's just put two more edges in there so let's go to 11 that gives us just a little bit more resolution over here to work with so I think that's I think that's good so just click to commit that and then we're going to come in and add a subdivision modifier so that we can look at this so let's do subdivision here let's increase its resolution to three so it's pretty high you can see it's a little bit hard to see uh but it's it's close enough that that should work pretty well but it's really up over here you can see that that color it's not matching at all and in fact because it's subdivided it's going way into the long flat area because we don't have another Edge till way way way over way over here okay in fact we don't even see it in fact maybe I don't even have one anymore yeah I've got one way over here so the subdivision mechanism is producing that curvature into the straight areas and we want to resolve that so let's press the K key and I'm going to click about right here come down make sure you press C so it goes all the way through click and then hit return and you can see how that affects this area so now we just have a little bit more work to do we want to remember where the Symmetry point is so I I will Zoom back out because when the more point you get the more difficult to can be to kind of figure that out I will select these original points and uh the pivot is set to go to the bounding box and that's actually useful for us I can use that to indicate where the center is I will select a single vertex there do cursor 2 selected then I'm going to leave edit mode just temporarily shift a we're going to add an empty there which is just going to be sort of an indicator for where we're going to have a symmetry point it's just there to kind of help us along the way so let's come back into edit mode Tab Key and we've got subdivision turned on and it can we're starting to get a lot of overlapping elements we've got the cage we've got the subdivided Mission we've got the original profile so I'm going to come over and click the on cage function just to sort of turn that off for a minute and now I can Marque key around vertices and I can move them now if you if you remember we're not in x-ray mode and so when you do a marquee selection on something it won't get the overlapped element so you got to keep that in the back of your mind press option Z and see then I can select that and move both points but I I think it would actually be even more useful let's let's pull this back and take a look at this for a minute if you're not used to subdivision surfaces this can be a little bit confusing we had put a cut in right there but when I turned off or when I enabled this on cage function you see there's an edge there but we also have an edge there so this allows us to edit the mesh directly the subdivided mesh directly and and this is suddenly way over there so what's going on well because it's being subdivided and there's not another Edge until way over here the subdivision is blending across that surface and I would really like this original Edge to be right there this is a boundary polygon and it needs to stay right there so that we don't have any curve influence coming past that so press the two key and then just come up here press the N key if this isn't available and then come down to crease and just type in a value of one and that snaps that in so we don't get any subdivision going past that in fact if we turn off optimal display we can see that the subdivision just terminates right there so that's really really useful so now when we come back in let's Zoom back in here let's go back into the on cage mode I'm going to come back into vertex I think it would actually be useful if we add a little bit more geometry right here so I'll press the K key and just drop that right there remembering to press C we don't see anything visual but it allows it to slice all the way through like it's in x-ray mode okay and then we put that in now we can just pull those up and we can do just a little bit of editing to get that curvature matched up just a hair more it's a small detail but I think that works pretty well just in terms of getting the two you can see they're they're fighting the blue and the black that means I'm very very close terms of my subdivision and the original direct curve that we modeled now we're ready to do symmetry because we've done some real fine-tuning work up there and we don't want to have to do that again down here on the bottom let's come down here we have all of this past this symmetry point that we don't need we're going to throw that out let's come over here and turn subdivision off temporarily I'm going to turn the on cage function off so we can just come in I'm in select box so I can just mark key down select those and then press the X key to delete those faces and then we just come over and we add a modifier so let's come in and do a mirror and it's going to use just the default settings I'm going to move that up to the top let's look at this in the front view this marker that we've put in we haven't named it it's it's temporary geometry I'm not going to worry about naming it but we're going to use that as our mirror reference object mode select this and we just need to rotate it down press the r key and then we can begin rotating that hold the control key and then we can snap so that we can get directly to a 45 degree segment there we have that work replicated for us we don't have to bother trying to do that I was being very fastidious right and so now we don't need to worry about doing that down there so let's come back over to our main object let's apply that and then in fact we don't even need that anymore we'll delete that we need to do the same thing top to bottom because we've got curvature down here and we don't have a symmetry point that I've saved so in in the profile the reference profile Tab Key one key goes into vertex mode select that edge and then do cursor to selected Tab Key leaves edit mode shift a and then we'll just add another empty right there so here Tab Key takes us back into edit mode Let's remove that bottom polygon so X key remove that face and then we'll move this up so G key and then along the z-axis press the b key so that we can just snap to that reference point right there okay Tab Key then we just need to come in let's add another modifier so we'll do mirror and then we need to again reference this object so it's the Z axis that we need so let's come over here and click Z and there we go okay so now let's go ahead and apply that these mod okay so now we've gotten this geometry ready and now we just need to get the width set correctly and the position set correctly let's come in and reset the object's origin which we can see is off over there so I'm going to do an object origin to Geometry then when we look at this in the top view we can just come over here along the y axis and set that to zero let's turn back on the face plates geometry Tab Key takes us into edit mode a key now the the pivot is way over here so let's just kind of move that so that we can see it s key and then tap y we can scale that let's come in and add one Loop down the middle and then uh let's go ahead and hide the face plates we don't need those anymore I don't even need we don't need this profile anymore so let's go ahead and turn that off uh let's do this let's come in take a look at this from the left or the right side and let's Zoom down now I've already got this geometry in place that's going to function for what what it is that we're doing in terms of the eyepiece that comes out but its resolution right now is kind of arbitrary and we're going to end up changing it in fact let me come in here and do a set origin to Geometry so it's in the middle but so this is just a reference point that I already have set up when we blend it together we need to have another Circle that comes around that imprints into this geometry that's going to form the blending zone between the shaft of the eyepiece and this body and that's what we need to put in place so uh shift s cursor 2 selected and then let's add another piece of geometry so shift a and we're going to come up to mesh and we're going to put a circle in view and let's do 0.5 and for this this is only going to be a reference so I'm going to make it pretty high just so that it looks very curvy and then I'm going to take it and I'm not going to match it I'm going to exceed just a little bit the size my eye is basically looking kind of at this area I'm kind of looking for a loop right there to sort of match up that top area let's come in back into edit mode polygon edit mode for the main Center piece of geometry and let's add a loop on either side in fact let's do this I'm just going to add it like that and then I'm going to select both of those period key make sure I'm in bounding box geometry s and then Y and I want to scale those out about like that okay next thing that we're going to do is we're going to focus on just this left side press the K key and let's start right up here and we're generally going to trace the path of that green circle and then down here all I'm going to do is come over and I'm going to click basically to the bottom you see I'm going on the outside just slightly and we didn't have any Loops down here which is okay let's go ahead and select this Edge press the two key and go into Edge mode bring up the context menu and then we're going to subdivide let's do just let's do six I think that'll work pretty well and let's go go into vertex mode it's easier to see these in vert with vertices select these and just kind of move them down we don't need to be super precise about this this is going to be the very edge of the blending Zone and we have some Freedom where we don't have to do anything in a super super precise way but that's going to be that's going to be good enough I think okay now this area right here we do want to make an adjustment to and so and and then this area right here the resolution is two course at that location so let's come back up to the top let's zoom in here press the K key this k key is super handy hold the shift it'll go right to the center click once and then come right to about there and then press Z and the C key and click to put in that new Loop and then here we just want to move this up so it roughly continues that curvature now it's got topology you can see it's got that angle which is fine press the G key once and the G key again and it puts us into that slide mode so we can just sort of slide that up into position about like that now I think I'm going to take both of these loops on either side here I'm G to press the S key and then y let's pull those in just a little bit just a little bit more but the next thing that we want to do is take note of the fact that this next polygon down is not a quad we're trying to primarily work with quads because we are working with subdivision surfaces and we will have maybe a triangle or two in but we want to come in now and let's do this let's come back in press the K key come down to this vertex we'll come in like that and then we'll do the same thing Z key and then C to place that and then what we find is that we've got a quad quad quad we've got quads okay that's the parameter we want to hit so let's come down here and take a look at this area because I would perhaps like to make the distribution a little bit better but our consideration is the fact that if we take a look at this let's come over in the front we have the curvature that begins here we've got a little bit greater density of polygons but the consideration is that we go into this buffer zone here and then down into a flat area and we have a little bit of wiggle room and this is one of the reasons why up front I wanted to make sure that I had sufficient resolution why we went from 8 to 9 and then I added two more up to 11 it gave us just a little bit better curvature Without Really compromising and making it more difficult to match up the the resolution of this shaft over here so what I'll do is come in and I'm going to come to this Edge which is in a planer region and we'll do the same thing G and then G again and I'm going to pull that down and we'll do the same thing here G and G and we'll pull that down and then one more here g g it's going to be subtle and it's not going to compromise the topology too much g g we'll pull that down that's going to allow us to adjust this area just a little bit so let's come in now and we need to replicate this work to the other side we also need to p patch up this area because we are working with subdivision surfaces and we do need to patch up the Eng gon that currently exists in this area uh we're working on this one/ half and let's go ahead now and start mirroring some of this work even if it's just sort of temporary I'm going to remove the subdivision modifier and we'll add a mirror modifier and and we need it to go along the Y AIS so let's switch over to Y we want we've already got geometry on the Y side so we need to bict it then we need to tell it to flip which side's being mirrored like that we can press this button the on cage so that we can see the change interactively while we're in the modeler okay so now let's come over k key click here and and then press the y key to come across to establish sort of that zone uh let's come into vertex mode it's easier to see and what I like to do is come in like this I'm going to use this Anchor Point and then I'm just going to come across really quickly y key click and then we'll just keep doing that y key click and return and then we'll just keep doing that now this one I could even come down here and anchor that it really just depends on what it is that you want to do both would work just fine and then down here let's come here click scroll down and we can come right to that Center Point and then I can continue this Loop going right to there to Anchor that and that's that's we're done I think I might come to this point maybe move that up a little bit so that's all we needed to do to dice that up to to make it subdivision worthy now we're going to do one more Loop coming in once we get the geometry in place that blends the two shapes together but we're going to tackle that in just a little in just a little bit let's come over here and apply now we can't apply in edit mode so I'm going to leave edit mode and click apply so when I come back into edit mode we can properly see how many edges that we have I accidentally got this I'm going to hold the shift key to deselect that there we go I've got the readouts over here so I've got 30 edges all I did was I came here and then I just turned statistics on and off that tells me that I've got 30 edges well that's really useful because let's go ahead and hide that Circle we don't need that we need to rebuild this with 30 edges so shift a come to mesh come down to Circle we come back to view let's make this half an inch because it's huge we just need to set in exactly 30 and then we can scale with the S key bring it down to the size of the blue reference line and there we go so now the original profile I don't need I can turn that off this is the one that matches so now we just bring this in and one thing that I'm not going to do is I could I could come up here in edit mode in vertex mode and I could take these and I could Contour them a little bit more closely to this I'm not going to go to that effort for what we're doing right here press the E key and then X to extrude X twice to extrude that shaft for the eyepiece option Z takes us out of x-ray mode and then Tab Key leaves edit mode we need to join these two pieces of geometry together so we're going to join there we go Tab Key takes us into edit mode and now we just need to create a proper face filled into this region so F key and then we just need to isolate let's go ahead into face mode press the W key to cycle over to selection Circle hold the shift key and we're just going to quickly select all of these bring up the context menu and dissolve those faces shift key selects that now let's look at this in the front or the left any of the views that you happen to want to view it bring up the context menu and then we're going to bridge faces there we go now the next thing that we need to do is simply come in and let's give it four Cuts initially but we need to change it to blend surface there we go look at that this is where we could come in to the smoothness we can adjust that to kind of find the contouring that we want so look at it at the top also kind of look at how it is that we're working and I actually think that looks pretty good this is where you could also determine do you need four or maybe three Cuts I think actually three Cuts is going to work because that gets me a little bit closer in terms of the rough size of the polygons that we're already subdividing okay we're almost done believe it or not we need to add a couple of boundary Loops in if we take a look at this in the front along this long shaft we want it to be flat and we have curved polygons coming into that so we need to add a boundary Loop about right here so we're just going to add that right there and let's come over and just automatically set the crease weight to one and that will prevent subdivided polygons from progressing past that boundary if we look at this from the right we have the same situation where we need to add some boundary loops around here because if we look at it from the top we've got essentially flat polygons along one axis coming this way but we've got curvature coming in so if we were to look at just this particular Loop we can see that we've got basically the same kind of condition we need to add a boundary loop around here to really make sure that that curvature is kind of stopping right there and not sort of loosely following all the way in so let's follow this from the right right side we have a logical oh and I've got four edges right here that have creasing set up to one we don't want that so I'm going to reset those back to zero that's easy then press the K key there's a logical point right here we can just quickly and Loosely roughly creating the same width polygons all the way down about like that and just come down so we get here and then you can you can make them look pretty if you want but we don't need to worry too much about it because this is going to be something that wouldn't show up very strongly but we have all of these planer polygons so if we come back in here let's selection Circle all of these now are planer to each other that gives us a lot of flexibility and how it is that we arrange those polygons so I've terminated the loops in a way that isn't creating perfectly Square quads they don't need to be in this planer region okay so that gives us a lot of flexibility but we do want to replicate this to the other side so let's go ahead and just replicate these Tab Key let's come over and add another mirror modifier just to do that for us we're replicating along the Y Direction so let's do y okay let's go ahead and apply that Tab Key takes us back into edit mode I said that we can have triangles in a subdivided polygon and it can handle that but we do have one little area here that I think we could probably optimize just a little bit we've got this gentle slope coming down and I think these two polygons we could probably optimize out so I'm going to select this vertex hold the shift key and select that one bring up the context menu and do merge ver vertices at last and that's what happens let's come over here and then press shift r that kind of optimized those out but as my eye looks at it I've got an angle here two triangles that if I remove this Edge in the middle we can dissolve that and have a quad so this is one thing we look for in in polygon meshes is we look for Loops that's something we always try and do is maintain these loops and by removing those couple of triangles we optimize the mesh Without Really radically changing the topology much and I think that works pretty well now the next thing that we need to pay attention to and the last thing that we need to pay attention to let's come over here into shading mode in fact um I've got a I've got a um material already on there I'm going to turn off let's come on and do shade Auto smooth and we need to make sure there's a slight Edge that I see right here and we want to come over and check to make sure that all the polygons have the same facing orientation and they don't so tab key a key come up to mesh come down to normals and then recalculate outside and that fixes that for us okay so let's come back up here and turn that off we need to add a subdivision modifier so let's come over add subdivision let's just set it up to two so we can see it nicely Tab Key there we go so we've got this Blended and now I'll be able to finish the model with this centerpiece being subdivided let's talk about possibilities for one quick one quick minute this type of geometry would be really easy to do with a NBS type of modeler um like I'm sure Plus icity moment of inspiration Mo myy 3D is it some sometimes called Rhino this type of stuff is something you could very easily go in and use with a nervs modeler uh somebody actually made a comment in one of my videos that said why don't you just use a nervs modeler well you could but if you don't happen to know how to use nervs modeling which they can be kind of complex then you learn to do it in the program that you have available to you and I also show you all this for the sake of learning how to manipulate geometry and then use it for subdivision surfaces to create geometry like this right it's not just about this model it's about the experience of polygon modeling and subdivision surfaces so uh anyway I hope you found this to be a useful tutorial for figuring out this kind of topology

Channel: Christopher 3D

Views: 3,792

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Id: 2lNIZxG8Xng

Length: 31min 54sec (1914 seconds)

Published: Mon Jan 29 2024