Booleans on Curved Surfaces in Blender | Perfect Shading

what's up everyone today we're going to talk about booleans and curved surfaces and blender uh specifically we're going to work with a sphere in this one so i'm actually going to be using vanilla workflow for this just to one appease everyone to show just the generic way to do it um without you know any shortcuts so what we're gonna do is start with a basic cube and whenever i'm working with spherical surfaces i always like to use a quad sphere so that way it's um not only is it consisting of quads and there's not any pinching in the top it's also an actual perfect sphere so what we can do to make that is take the cube press ctrl 4 and yeah ctrl 4 should be enough for now we'll go ahead and shade it smooth and then we'll go and apply the subsurf next we need to cast it to a sphere because if we look at it from an ortho view um it's it's skewed it's not a perfect sphere it's not perfectly round so we're going to add a cast modifier change it to sphere and put a factor of 1 not 10 1 and now it's a perfect sphere you can see the difference before and after much better anyway so now we have is this piece here and goodness i was messing with my settings earlier i cannot deal with blender's default vertex size way too small for me this will do seven for that okay so usually when you do booleans in a curved surface you want a fairly dense sphere this is probably a good middle ground right here to kind of discuss all the intricacies behind it so i'm going to just put a hole directly in the front maybe the top right quadrant or something and we'll use a cylinder for that so i'm going to just add in a basic cylinder here let's give it some smooth shading auto smooth and then what are we at 32 verts by default yeah that should be fine so rotate this 90 degrees put it up here somewhere scale it and that should be good enough so now we can just run a boolean difference operation turn on screencast keys so people can see what i'm doing okay so now we have this the shading looks terrible obviously that's not a big deal we're going to take care of that so maybe i'll move this out a bit so it's not so far indented right about here and you're going to see the shading is pretty terrible it's really easy if we um shade smooth the cylinder which we did and then turn on auto smooth for the cylinder as well okay so we have this and it's non-destructive so we're just going to apply the boolean modifier and this is basically what we have right here now this is a good situation of a good even amount of geo on both the sphere and on the cylinder what you want is the amount of vertices on the sphere to roughly match the amount of vertices that are around your cylinder and let me show you why this is so important make sure you pay specific attention here okay so this is a mech i was working on i'm probably going to have to redo the head part because of this specific issue so you're going to encounter it and you need to remember just keep this in the back of your mind so take a look at the density of the main sphere here not super dense that's the first mistake i made i should have probably made it one subdivision higher two the cylinder i used to cut out has way more vertices in fact it was a 64 v cylinder and it has way more vertices than the actual sphere has so it's really hard to control the shading and let's go back to our initial example and see how it's different you can see we have roughly the same amount of vertices going around the cylinder as we do vertices making up the sphere here it looks it looks like it all fuses nice together it looks like it's nice and even so think less about the amount just if it doesn't look even like right here this looks super uneven you immediately your eye goes right to these vertices here way too many compared to the amount of verts on the main sphere whereas here it looks roughly even not to mention we're going to be merging some of these vertices anyways now this is mostly intuition here so i'm trying to convert my intuition to an actual tutorial so hopefully it's making sense so far anyways what i'm going to do now is clean up the shading here after we add a bevel of course because it's hard surface we want bevels so i'm going to show you how to clean up the shading with a good example a good even example like this then i'm going to show you two common mistakes and examples that kind of destroy this type of cutout okay so first things first with a cutout like this you want to merge all the near misferts so the ones that are super close to each other get rid of those guys right off the bat so anyone that values their time would run a boolean cleanup with a mesh machine way quicker that way but um you know i don't want to sound too cocky or anything i understand i really do understand that there are situations which people genuinely can't get an add-on just for the most part when you can invest in one it's worth it i promise but i'm going to just show you if you don't have mesh machine unfortunately your only option is to go in here and start sliding vertices manually and once again the vertex sliding is mostly an intuition thing as well that you kind of see the more you work with these types of cutouts so we're going to go in here and merge that at last so you can just see it's a pretty easy process here we just got to start merging things and i don't want to disrupt the curvature too much so you got to be careful with it so you know it's sometimes kind of a a fun experience it's it's like uh you ever seen those videos where people do like those super satisfying cake cuts or whatever it's kind of the same thing when you start merging verts and cleaning this up it's just a it just feels satisfying i don't know what it is maybe just because it's a little bit more aesthetically pleasing so like i said this is just mostly an intuition type of thing you just merge where it makes sense right and eventually the more you work with these types of cuts you'll discover what makes sense and what doesn't and there's still some situations in which it's like a a hit or miss you might be moving to the wrong vert you might not but in general you want something like this where it's you know somewhat clean doesn't have to be perfect though okay so this looks pretty good but i can already tell the bevel is going to go crazy when we add one simply because the bevel needs a little bit of room to you know round across and some of these vertices like this one the bevel's just going to hit this one it's way too close so what we can also do is just kind of help that before the issue actually exists move some of these around and this one's going to be an issue i will deal with it on a case-by-case basis but for now we're going to get in here and add a bevel modifier set to angle three segments is usually what i go with you can harden the normals to make it a little bit cleaner and turn off clamp just put the bevel right to where you want it to be in general we don't need a crazy high bevel just enough to capture the reflections so right around here should be okay so after adding the bevel and moving and merging the vertices around you can see the shading here looks pretty good never trust the default studio shading though always go to a reflective mat cap like the car paint this is one of the the cliche mat caps you go to and you can really start to see shading breaks as you go around now this one here i think that's a shadow if we turn off shadows yeah that's just a shadow be careful of those because they can get a little bit tricky but if we look at steep angles you can see the shading starts to break around the bevel and the fact of the matter is if you have end guns there's no way to get those end guns to have perfect shading there's only a way to manage the shading by pulling in those end guns really really close to the bevel so it's barely noticeable in my opinion if you're doing a render from a distance and you can't see the shading errors in the final render i personally think that is fine i've done it before and you can never notice them if you want to do it the proper way and actually have perfect shading this is what you should do so the shading errors are much more constrained obviously but we want to get it to be perfect with no errors at all so what we're going to do is actually add in another quad sphere we're going to add in a cube press ctrl 4 because that's what we had before we'll shade it smooth we can apply the subsurf and then same thing we did the beginning we're going to add a cast modifier set to a factor of 1 of course set to sphere and now you're gonna see we have the exact same general shape here so what we can actually do is we can take the normal information of this sphere and transfer it over in vanilla blender so the perfectly smooth shading that we have on this sphere we can transfer directly over to the sphere with the boolean with a bad shading around the boolean super easy process all we need to do we'll just hide the sphere here we'll go to the one with the boolean all we need to do is either apply our bevel i would recommend actually going in here and beveling manually i just find the controls a little bit easier so we're actually going to go in here and bevel manually you have to go destructive for these bevels so we're going to press ctrl b and you can give this as many segments as you want it doesn't really matter we'll just ramp that up and if you want you can clean up the vertices some more to make it less warped if um if that's what you want to do it's not really a big deal though okay now we want to do is go into face mode and alt click the first bevel segment of our bevel and then we're going to press control plus on the number pad maybe like two or three times and then we're going to press alt shift click and deselect all the beveled areas we don't want to transfer the normals on the bevel it's not going to work so this is roughly the area we want to have here selected so now we can do is go over to the vertex data panel and just assign a vertex group really easy we just want to make sure these are the faces that select in the vertex group next this is the final step we're going to go to add modifier data transfer we're going to transfer from this sphere right here so in this case it's called cube001 we're going to go to this third option down let me drag this out custom normals and then we're going to go to projected face interpolated now if we go into object mode it's going to look really really weird that's because we need to make sure we select the vertex group that we just made so now we've transferred that smoothing information from that last sphere and now the shading is absolutely flawless there is no error at all so like i said i think this is a bit overkill if you can't see any shading errors and you're rendering from a distance but this is an option if you want to get perfect shading now let me quickly show you two examples that uh people commonly make when they're doing booleans and spheres one of which i already showed you at the beginning of the video okay so first one i showed you is pretty obvious let's um let me go back to a regular matte cap let's add a cube this time we'll press i don't know we'll do a really low amount of geometry for this one so ctrl 3 for a sub surf with three subdivisions shade it smooth apply the subsurf we'll cast it to a sphere and now you're going to see that we have a sphere here but it's really really low in terms of mesh density i see a lot of people take these low density spheres and then use a cutter with an insane amount of vertices so like i've seen people go up to like 80 or something crazy and this is basically what i showed at the beginning of the video so if you try to cut this you know run a difference boolean we'll apply the boolean and we'll just turn on auto smooth here so check this out we have way more vertices around the cutter than we do to help constrain the shading on the base of the sphere so now trying to manage this shading error is going to be super hard because rather than having a lot of vertices around here to work with we have pretty much an uneven amount of verts so the shading is going to be a lot harder to constrain so this is issue number one low mesh density on the source object high mesh density on the cutter object that's a big no-no so another common mistake i see people make is the exact opposite high mesh density on the curved object really low mesh density on the cutter objects so let's add a cube here and maybe we'll do control five so one more than we did before we'll go ahead and shade it smooth turn on auto smooth and then apply the subsurf cast it to a sphere the usual stuff we've been doing so we have a pretty good amount of vertices in here you know it's um a lot more than we had before so some people will do this and then what they'll do is they'll take their cutter object like a cylinder and have something insanely low like i don't know 16 vertices or something low so rotate this 90 degrees and you know use this the cutter object go in here and we'll just go ahead and apply the boolean and this is another issue people make so although it looks like the vertices are pretty even it's really obvious because we have the stepping error we have a really jagged cut in the sphere here and it just doesn't look good it doesn't look round at all it looks steppy so like i said earlier the most important thing when working with spheres is to match the mesh density of the source object with the cutter objects so make them as even as possible don't have any sort of bias in terms of mesh density so if you're going to go with a really low mesh density sphere like this so we'll just do the usual thing if we don't have that much geo in here then do the same thing with your cutter let me cast this so with your cutter have roughly the same idea low mesh density on the cutter so in this case you know 16 or maybe like i don't know 24 might work okay and then when we actually do a cut sorry this is taking so long but i want to make sure i'm showcasing so now you can see everything is roughly matched it is a little bit jaggedy but overall the sphere is as well because it's not that dense and same idea for a much more detailed sphere cut you know something like this your cutter should have something a lot higher like 60 to 80 verts to match the general smoothness of your sphere i'm not going to do it again you get the point so hopefully this video makes sense i tried to explain the intuition as much as i could with examples here if you have any questions at all post them in the comments i'll try to clarify everything so hopefully this now makes sense for how you can work with booleans on curved surfaces constrain the shading errors and actually transfer normals if you want perfect shading obviously there are exceptions to everything there might be a situation in which something i said here doesn't work perfectly but that's a case-by-case basis and at that point the intuition is going to kick in and it'll make sense so yeah this is basically all you need to know about curved surfaces and booleans if you watch this video i guarantee you're going to be good to go with hard surface on curved surfaces so that's about it if you do want to get mesh machine however remember when i discussed earlier having to merge verts is really annoying to do manually and you just want to do it in one click i've dropped an affiliate link to mesh machine in the description so if you do choose to buy that it'll help support me as well i use it all the time so yeah anyways hope the video helped and i'll see you in the next one

Channel: Josh Gambrell

Views: 34,010

Keywords: blender, 2.8, booleans, on, curved, surfaces, spheres, curvature, cleanup, topology, perfect, shading, mesh, machine, hardops, boxcutter, hard, ops, tutorial, beginner, artifacts, issues, error, josh, gambrell, masterxeon1001, ponte, ryuurui, complete

Id: NZXYWzv02m4

Length: 15min 36sec (936 seconds)

Published: Mon Aug 24 2020