Advanced Subsurf Modeling - Techniques to Avoid Pinching

[Music] hey this is Chris plush from CG masters and in this tutorial I'm going to show you a way to avoid creasing and pinching when you're subsurf modeling so here we have a cool Subaru model from Lumiere Sinofsky own blend swap there and just like with most 3d car models there are some of the use of creasing and pinching issues here it's just a very common occurrence when you're subsurf modeling and these issues occur when you're adding details to curved surfaces because adding details like the hole in the front of the bumper here and the hole in the side of the bumper there they're going to change the topology of that curved surface so that's gonna change the curvature and the way it reflects the environment so I'm gonna show you a way to avoid that in this tutorial alright so let me grab the front bumper here and bring that into local view and see what's going on with this so with the shading I have in the viewport now it's actually kind of hard to pinpoint exactly where all the flaws are so I'm gonna go into the right side toolbar and I'm gonna change the matte cap to a very harsh unforgiving and judgemental red this is gonna show you every single solid hairy flaw on the surface of your model which is extremely useful for hard surface modeling I basically just leave this turned on all the time and I like that it's red - it's like the color of errors so it's kind of yelling at you the whole time to do things better alright so now we can see where all those flaws are so you can see the waviness and the distortion in the reflections when these reflections should really be passing through this section here very smoothly but instead they're very distorted and that again is because of adding details to the curved surface this particular model here has a hole cut out on the left and a hole cut out in the front and this extra geometry and just changes to the topology affect the curvature of the surface and that affects how it reflects the environment so that's why we ended up with a lot of waviness here and even if you're very careful with laying down topology for areas like this and very systematic in your approach to adding these extra details to the curved surfaces it's still very hard to avoid problems with distortion or creasing or pinching so now I'll go over a technique that helps avoid that the first step would be to model the bumper without any details that just makes it easier to achieve a nice smooth curvature so I've already done this in layer 2 so here's our front bumper without the details you can see this the curvature of the surface is much nicer and the reflections pass through it much more cleanly so that's step one create your object with perfect curvatures first and without any of the details that might ruin that curvature so now step two would be to duplicate this object and add the extra details to the duplicate which I've already done in layer three so here's our bump or duplicate with the holes punched out in the front and the side and cutting these holes out affects the topology and therefore affects the curvature and leaves us with creasing and some waviness so what we're gonna do now to fix that is simply shrink wrap this mesh on top of our guide mesh right here because this has that nice smooth surface we're looking for so we're gonna make use of that by shrink wrapping this on top of it so let's do that now by going over to the modifiers and add in a shrink wrap modifier and from the target field we'll choose our guide mesh which is called guide mesh bumper and there we go so now we have a nice smooth surface but we still have those details cut out of it because we're shrink wrapping this on top of our guide mesh right here now there's a few important things to note here the first is that I added the shrink wrap modifier after the subsurf modifier that allows us to put all this extra subsurface geometry to good use by shrink wrapping that on top of the guide mesh and that allows us to achieve the most perfect and most smooth surface we can using this technique if for example the shrink wrap modifier was above the subsurf modifier it would only be shrink wrapping the base mesh vertices here instead of all the extra subserve geometry which makes things better but you can see it doesn't make it as smooth as it could be we still have some pinching in the corners of those holes there so let me move that back up so with the shrink wrap modifier below the subsurf modifier it just has a lot of extra detail to work with to create a nice smooth surface for you now another thing to note is that the faces of your guide mesh must be smaller than the faces of your base mesh that's being shrink wrapped onto it if these faces were bigger let me show you what happens real quick so if we had these nice big faces right here and we shrink wrap all of these little faces onto these large flat areas we're gonna end up with a segmented look so let me refresh the shrink wrap modifier now and you can see with all those little squares being shrink-wrapped onto those larger flat areas on the guide mesh we end up with this paneled segmented look here so that's no good so your guide mesh should be at least two subdivision levels higher than your base mesh so let me bring that back up to four and let's go back over here and we'll refresh shrinkwrap modifier and it's back to being nice and smooth so that does it for step two now step three will be adding thickness to this without the shrink wrap modifier affecting that now before we go and add thickness to this the first thing we're gonna do is make sure that all of the vertices are as close to the surface of the guide mesh as possible because for example you'll notice that some of the vertices like these right here there's a big gap between these vertices and the shrink-wrap geometry these actually have to move quite a bit forward to meet up with the surface of the guide mesh and that can cause some issues when we go to extrude things in for thickness so what we're gonna do is get out of edit mode and I'm simply going to apply the shrink wrap modifier which is going to move all the base vertices to the surface of the guide mesh and the goal with this is just to make sure that our base mesh right here is as close to the same shape as the guide mesh as possible that's just gonna make everything cleaner in the end and avoid any potential problems when we go to add thickness so now let's add that shrink wrap modifier back in and we'll choose guide mesh bumper as the target now everything looks the same and as smooth as it did before the only difference is that the vertices here where there once was a gap are now flush up against the surface of the guide mesh and that's going to avoid any potential problems when we extrude this inward all right so with that out of the way now what we're gonna do is actually add some thickness to this now when we go to add thickness to this we want to make sure that we have some nice sharp beveled edges around the rim and we'll achieve that by adding some extra edge loops around the rim so I'll press ctrl + R to add a loop cut then I'll press E and an F to align it with the top there and I'll drop it right about there alright so I've gone ahead and added in the extra edge loops necessary around the rims and in some edge loops around this cutout here extra edge loop near the top rim there the sides and the bottom I didn't add any extra edge loops around this cutout here because we're not actually gonna be giving this any thickness that's just going to be a gap so we've got all the extra edge loops we need for some sharp bevels around our rims now so now we can go ahead and work with the solidify modifier to add some thickness to the bumper so now let's go over to the modifiers and add in that solidify modifier this is the quickest way to add some initial thickness to your object and when using these techniques it's actually the best way to do it as well all right so let's check out the rim make sure this is the right amount of thickness and it actually looks good at the default value so I'm gonna leave it at that however I do want to get rid of the interior faces here since they'll never be visible so over in the modifier I'm gonna enable only rim and that'll just give our bumper object the rim up top here you'll notice now that the rim that the solidify modifier is not making use of the subsurf modifier given the fact that it's the at the end of the stack so that creates a little bit that creates some weird shading and just too sharp of an angle there so what I'm gonna do is apply the solidify modifier and that's going to add that extra geometry to the base mesh itself however you can see that that extra geometry is being shrink-wrapped onto the guide mesh so we lost our rim so what we're gonna have to do is exclude those vertices from the shrinkwrap modifier so that's what we'll do now so let's go into edit mode and the first thing we'll do is we'll get rid of the vertices on the inside of this hole here it's like I said we're not adding thickness of that so there's no need for those vertices to be there and the second thing we'll do is because we applied a solidify modifier to a mirror object it created these extra faces in the middle which is creating some weirdness so let me select all these faces press X and erase the faces and that fixes that up nicely so now what we're gonna do is select all of the new rim vertices that we made so I'm gonna hold alt right click on that edge loop there and let's grab the rim around the middle cut out as well so I'll hold alt and shift and right click on that alright so I've got all the rim vertices selected so now let's go over to the vertex buttons here and add a new vertex group and then we'll click on assign let's get out of edit mode and let's go over to the modifiers now and in the vertex group field of the shrink wrap modifier let's load in the vertex group we just made so right now the shrink wrap modifier is only affecting vertices in this vertex group but we want it to be the opposite so we'll simply click on the icon next to that which inverts the influence so now the shrink wrap modifier is affecting all the vertices except the one in that vertex group so that gives us our rim back awesome so to finish off the rim here what I want to do is add a bevel on the inside we have a bevel here catching the light nicely but it kind of just stops dead on the inside there and that doesn't look very natural to me so on I want to add a bevel there without adding all the extra faces on the inside so what I'm gonna do is use a solidify modifier to basically give the rim a room of its own so let's add in a solidify modifier and again we'll choose only rim and then click on apply so now we've just given our rim a rim of its own and let's go into edit mode and let's delete the vertices around this cutout and we do have some congested vertices around areas like this and that happens sometimes with the solidify modifier this area is not actually gonna be visible so it's perfectly fine to keep it like that but if you did want to fix it you would just select one vertex at a time press G twice to slide it away from all the other traffic well slide that down and then slide it up and voila that's fixed all right how's everything looking it's looking pretty good we just need to address one more thing and that's how its kind of lopsided right here now I mean this isn't even that big of a problem you can leave it like this and no one's really gonna notice but we're gonna fix it anyway just for the sake of thoroughness so the first thing I'll do is I'll select the inside rim right there and I'm gonna press G twice and I'll slide that up higher because I think that was way too thick to begin with and that was a big cause of a lot of the lopsidedness as you can see that fixed it quite a bit already so now what we're gonna do is add an edge loop down the middle that's not only going to help with the shape of the rim but it's also going to add some extra geometry in the area and that's going to make the bevels on the inside and the outside a little bit higher resolution so let's press ctrl + R add a loop cut straight through the middle of the thickness like that and we'll drop it right in the middle alright so now what we got to do is just round off this side a little bit and this part is easy what we're gonna do is just select all of the edge loops around that corner all the way around so once we have all of those vertices selected let's get a good view of the lopsidedness and what I'll do is press G twice and I'll move that down until I have the right roundness that I'm looking for and I think that looks pretty good to me so pressing G twice just slid all these vertices inward like that and we did that until we had the right shape and everything's looking good now all right let me double check around the entire rim make sure everything's looking good it does let's go around to the top looks good up there cool so that does it then alright so here's the final product here and you can see the reflections are nice and smooth as they pass through all the different curved areas and by comparison here is the original bumper wavy and distorted and here again is the revised bumper smooth and sexy now the cool part about this technique is that once you understand it it actually speeds up your workflow while producing a better result I mean you can't really ask for much more than that the only downside is needing those extra guide meshes in your blend file however these don't actually increase the render time since all of these faces aren't actually being rendered so there's really no need to worry about it now I just want to point out that it wasn't my intent to take someone else's model and be like hey I fixed it no no no because like I said every car model I see has similar issues they're just common problems when subsurf modeling and it's not always necessary to make things perfect from every angle either for example take a look at the final render like this is a good render and you don't see any of the problems we were seeing on the bumper because he's angled the camera and and made the lighting and reflective environment in such a way that you don't notice those flaws however I mean it's always good practice to strive for perfection so let me know what you think of all this hopefully you find it useful there's a lot more that can be done with this technique and a lot of different things you can apply it to but I won't get into all that in this tutorial but if you want to learn more about this technique plus learn a ton of other modelling techniques check out my training course complete vehicle production in blender it's a step by step guide on creating this Jeep Wrangler inside and out including all modeling shading and rendering it in cycles so check that out at CG masters net or follow the link in the description so that'll do it for this tutorial and I'll see you around [Music]

Channel: CG Masters

Views: 139,124

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Id: 3rlMzsBWtPY

Length: 14min 1sec (841 seconds)

Published: Thu Jun 01 2017

Reddit Comments

[u/pssdrnk]

oh wow... that's pretty hardcore, also right now I feel like john snow... I know nothing