Editing UVs with Modeling tools in Blender

all right everyone we're doing more Geo noes so last video we made this nicer sleepy too and I've duplicated the same setup we had in that video but for the shirt except I haven't done the UV map yet if you haven't watched the last video go watch it because this is a direct continuation and it won't make sense without it so in the last video I had to do UV cleanup on the sleeve before we could read apologize it and I did that with the UV tool add-on which I then realized I had confused with the text tools add-on UV toolkit is paid text tools is free although they have the same features the ones I use exist in both and many other add-ons like UV squares is also free and it has snap with equal distance which is the same as the distribution tool from uh UV toolkit so then I went to put text tools and UV squares and stuff in the description of the video and I realized text tools hasn't been updated for blender 4 .0 and it's broken and this just reminded me how much of a hassle it is to edit UVS at all and that is why the subject of this video is how we can change our UV map with mesh editing tools so that we never have to worry about any of this UV add-on stuff ever again all right so a UV position is just a XY position for each vertex which is why we can make this mesh which just inputs this mesh and sets the position to be the UV although you know rotated by Z that's what we learned last video so we just want to go the other direction we want to take a mesh with whatever position and then tell this mesh to use that as the UV map and that's exactly what we're going to do but there are a few things to keep in mind first let's turn off everything we don't need and I'm going to grab a copy of our UV ref mesh and visual geometry to mesh which is the same as applying everything and now I can go into its UV which is the same and if I start making changes to this mesh like going to go for active element which means that it uses the highlighted vertex so now if I do a SX scale on X it straightens everything this is the same functionality as some of the straighten tools I was using in the previous video and so it's pretty easy to turn this into a clean rectangle X not Y and now the loop tools add-on which comes with blender and you can go enable has the wonderful space command to evenly space things down an edge Loop so do that on everything and if we now want to clean up the interior of this shape we can go into our sculpt mode and get the smooth brush and set it to autom mask mesh boundaries and now we can just smooth this out and it won't affect the interior or it only affect the interior and this is literally the same as the UV smooth brush in UV space so we're already editing our UV map as mesh that part is easy now it's just a matter of how we get this back over here now we changed the mesh now we need to update the UV map we can do that with projection view now it's got the new shape but it's shifted everything because the camera wasn't exactly aligned like before we can do a projecton bance which is consistent but that's will stretch everything so the way we could fix this is we add a plane and this plane will be naturally 1 by one so we would need to scale it or it's 2 by two scale it by 0 five then move it up by 0 five and now if we project from bounds and that's side now we could keep a consistent bounds and then this would be user to work with but this causes a bunch of problems because we' have to then delete this plane after otherwise it messes up the index order when we transfer things back so that's something we will solve with Geon nodes do all of that junk so before we fix that we'll just do the regular projection view even though it's flawed and I'll show you how to get this UV map back onto the main mesh which is pretty simple we will get the data transfer modifier we will uncheck this object transform because then it lines things up based on their origin points so it will count these two things as being in the same place even though they're offset visually that just makes it easier to work with we'll Target that face data topology UVS now we have updated it so if we go back here and we make some other change and then we update it again it's going to keep updating because that is a live data transfer modifier but we have to keep doing that step of projecting from view so that's the part we're going to automate with Geo nodes all right so first things first I'm going to add one of those planes like I had earlier and I'm going to set this to wire View and that's just there so that we can keep track of our UV bounds we're just going to call that rebounds ref and now what we're going to do is a Geon noes group that updates the UV map from the position as we go so let's get a switch over to Geon noes here this is going to be a very simple group we're just going to get the current position of the mesh and a store named attribute and for it to actually update this UV map attribute rather than just making a generic attribute called UV map we need to set to the right type so that is a 2d vector and a face Corner if it's set to anything else it won't write to the right attribute even if we put it in here so as soon as I have this on this disappears because currently everything is set to zero so we will set it to position and now it's a squished line and that's because it's expecting an X and Y only it's only a 2d Vector but this is an x and z so we essentially have to undo the transform that we've done before so let's get a vector rotate on Oiler and do a minus 90 transformation and now it's there but it's offset by a bit so we also want a vector math and we'll add 05 and now things are lined up again and we could add a multiply for scaling this as well if we wanted so if we hadn't done these offsets in our existing geod noes group uh in our unwrapped group here we wouldn't need to redo them if we just left everything alone but or we could potentially even like record these and reapply them or something but for now this will be good enough so now as we work this is just updating in real time so now we can actually get in there and work on our UV version of the mesh which I'll bump over a little bit more and it's going to be actively updating this stuff Stu and it's updating the UV here so that means if we move this patch around that's being projected our retopology that's already good to go and it's working live on these changes so keep in mind that we are working with a giant restriction here anything we do has to not change the number of face Corners in this mesh and you may be wondering what is a face Corner well you know what a Vertex is and you know what a face is you know what an edge is well face Corners are the secret hidden fourth data domain and every face has a corner for each vertex so a quad like this has four corners and basically face Corners are what allows you to have different data on different sides of an edge they allow like split meshes so for example if we go into vertex paint we can work on either face or vertex mode so if we're working on vertex mode we paint a vertex and then it's coloring the corners near it this is interpolated across the face to the next uh vertex and if you have the same value on everything then the face will be a solid color or we can undo all that don't know why I have to hit the by multiple times to get one thing all right or we go to face mode and now we're painting on just the corners so it's called face mode but it's actually face Corners mode but uh they hide the that the existence of corners from you so now we have different values on both sides of this and this is possible because of face Corners so you may have noticed when we did the UV transfer over here this data transfer is set on face Corner data and that's because UVS are face Corner data because you need to be able to split them into Islands whereas if they were vertex uh data then you couldn't split things and if they were face data it would always be the same value for the ENT entire phas and wouldn't be useful so this is a long way of saying that we can change the number of vertices just like you do in the UV editor but we can't change the number of faces or face Corners so we can do something like merge these and also merge these These are darts from marus designer and everything is still happy it hasn't broken the transfer anything and now I can actually get rid of these unnecessary extra seams and we can proceed in cleaning up our mesh but as soon as I do something like add a face now it's broken the transfer this is actually this actually doesn't have to break the transfer the data transfer modifier has a feature where if the meses don't match well enough it'll throw this error and shut itself off but if instead of using the data transfer modifier we Ed a jobi TR noes group then it wouldn't care about this extra face and the reason for that is because when you add a new face like this it's going to be added at the end of the index order of the mesh the way these transfers work is it's transferring the data from face Corner one of this mesh to face Corner one of this mesh so this new face is going to be face number face number 495 so it goes to transfer data from 495 and there is no 495 in this version so just nothing happens so the reason that Geo uh so Geon noes will allow you to do this transfer even if you add stuff it just won't do anything but it won't break whereas the data transfer modifier puts this error in to protect you because if the new face changed the vertex order or the face order and caused it to recalculate the order then it would mess up everything so technically we could uh get around this but there's no not really any reason we would want to and another thing I'd like to note is that currently we are using this other mesh to update our UVS and that's so that we can hand model it if we were doing something like procedurally changing the UVS we could do that purely in Geo noes without needing this extra mesh and then as we updated the basis like if we were using a lattice to distort these UVS into a new shape then it could all be procedural and non-destructive so this is a destructive workflow I'm showing you and maybe in the future we'll get to non-destructive stuff but for the most part this is what you're going to want anyway all right well that's that's pretty much it for the Geon noes actually like that's it like it's that simple uh now you can do all of your UV editing as mesh with the full Suite of mesh tools with you know great add-ons like Loop tools and with sculpt mode and you know you could use an Armature in the future we're going to look at some fancy stuff like how you can use uh converting the corners of islands into curves and then turning those curves into a box of stretching things into boxes but we're going to take things one by size at a time so we're not going to talk about that yet but I don't want to leave everybody hanging so let me show you a quick way that we can work with this that would actually solve some of these problems so I'm going to check this stuff down here for now and let's focus on just cleaning up this piece and I'm going to show you a way to clean this up and then retopo it so this isn't going to be a clean rectangle but we can get it cleaner than this let's start off with using that active element and scale on Z to zero scale on X to Zero scale this one next to zero I want to keep this lined up here because on the actual garment it's important to keep that so i' like everything else to be evenly spaced but this part isn't actually drop that down we'll hit the stuff with the space tool and same thing over here my general policy is that I set everything to be the furthest out point there space this but not with that last Point selected so now our boundaries are pretty cleaned up actually I shouldn't have done it on this one down here so let's that again no problem nice and easy so that's pretty clean and now I want to clean this up in sculpt mode so well we've got our smooth brush again and now it's going to mess that Loop up so another trick you can use is if you hide this that as far as it's concerned that's the boundary now so we'll just Spam this now I should note this is a quick and dirty way and this works because this mesh already has basically even uh vertex distribution CU that's the point of marvelous designest topology if you're making your UV map some other way there's no guarantee that this is going to give you a clean result cuz this just tries to evenly space things out when you use that smooth brush all right so I'm pretty happy with that that's good enough now we have to figure out how we use our retopo input to make something useful here so I'm going to snap that there and that there and let's just make a nice big grid and I've still got my active element alignment so I'm just scaling to zero and let's get this stuff lined up with that top Point all right so now we've got the bounds and now I'm going to turn this into a grid start that there now I know I want about the same resolution as this so that's 1 2 3 4 5 six so we'll put six there and match that here it's about the same size and I guess that looks like it's about square right this could be more precise but I'm sure it's going to be good enough so I want roughly this and if we look up here that's already being projected on by a g noes group it's just that everything that is off the UV map is getting stuck to the closest point on it which is looking pretty bad at the color but I would be pretty happy to have this maybe I'd do the Ed a bit differently but this is a way that you will see topology done sometimes if your goal is just a very even Square grid which may not be the thing you need every time but it is good to have so I just want to cut out everything outside the pattern so I could go through with the knife tool and start doing one for every vertex and this is kind of manual and tedious so there's an easier way to do that process which is I'm going to copy this because this is a live Geo noes mesh or not this one copy that I'm going to drag it out of the collection and visual Geo to MH and I'm also going to copy this because I don't like doing the start to things on the same mesh and um I'll keep this one and use that one because that's what's being targeted Here and Now what we can do is use the knife project tool so here's the procedure you select the mesh you want to cut and you go into edit mode then in the outliner you shift select the mesh you want to cut with it has to be shift select which is annoying if you have multiple things in the collection because it will select everything between these if you do a control select it bumps you out of object mode it's a bit weird but that's why I move this out of the collection C so we shift select then we got a mesh knife project and it has cut the cutter mesh into the target mesh and now we have all of that and we actually have a bunch of internal stuff that we don't want undo that cut we will modify our cutter mesh I'm going to grab just the edges that I want delete everything else and then I've got a double here when I had seams earlier so we'll do a merge by distance now repeat and we have those edges cut in now to quickly get rid of all the external stuff let's Loop select these Mark a seams and go into face mode and now you can use l to select just faces in that island and delete them and then we can delete those seams so now we have the right shape and if we look up here that's actually behaving very nicely but of course this gives us uneven topology on the edge we should clean this up and dissolve some verts and depending on what you do here you could end up with Eng gon like this is not a quad so you know this is a if this this isn't necessarily what you want for your retopology so you could move on from here and clean this up more and resolve it to what you want or you could do something totally different um since you have the Slade flat you could do some non quad non- grid topology I'm a big fan of that to clean up edges say I for extrude inner but I don't have the right settings so we'll talk more about that other the subject in later videos I haven't really decided how I want to handle it for this outfit anyway but for now I think that's it thanks for watching please like And subscribe I'm going to keep doing like little blogs as I continue working on this character so also follow me on Twitter for more regular posts and seeing how things work and also that's the easiest place to ask me questions I think the next video I'm going to talk about wrapping things onto other things and displacing so that you can get volume off of a mesh so stay tuned for that

Channel: aVersionOfReality

Views: 9,591

Keywords: blender, 3d, uv, uv unwrap, uv map, geometry nodes, retopo, retopology

Id: evs09WDe5tU

Length: 20min 24sec (1224 seconds)

Published: Fri Mar 08 2024