How to fix artifacts in Blender

hey guys josh here and in this video i want to discuss how to fix artifacts now undoubtedly you've been modeling and you've ran into little problems kind of like you can see right here where artifacts appear it basically is just glitchy geometry showing up on your mesh now a lot of beginners and even intermediate users don't exactly understand how artifacts work and why they're occurring so i just want to show some basic examples and how exactly you can fix those so i'm going to start with a basic cube here i'm going to be using the hard ops add-on just to kind of get some quick bevels and things like that so we'll go ahead and add a bevel here and just give it a nice amount something like that should be okay and then what i'm going to do is cut a hole in the top just for demonstration purposes so i'll add in a cylinder we'll do an sharpen and then pull it up maybe make it about that size and then if i hold shift and do a difference boolean you'll see that we have a nice cut here but there are some very clear and ugly artifacts showing up now what most people do is they adjust things like the bevel without really understanding what's happening so one of the obvious solutions to fix this is to just make the bevel a little bit smaller and usually the issue will be rectified quite easily but the number one most important thing is to understand why these artifacts are even occurring in the first place so what i'm going to do is select this object and then go into the object properties panel and under viewport display we can tick on the wireframe view i also have this mapped to the semicolon button just because i use the wireframe view quite a lot so yeah go into wireframe view and you're gonna see kind of what's happening overall the areas that don't have artifacts have very clean topology but the areas that do have artifacts have topology kind of all over the place and you'll see that once you adjust the bevel this topology starts cleaning up very nicely and that's kind of why the artifacts disappear once you adjust the bevel upon closer inspection however you can see that the reason these artifacts are occurring in the first place is because this geometry is intersecting with each other so whenever we get this intersecting geometry blender has no idea how to render this in the viewport so we get these ugly shading issues so as for the topic of this video fixing artifacts all you really have to do is fix any intersecting geometry and then your rendering is going to be pretty clean it's easier said than done because some models are way more complex than others and at the end of the day it's up to you to find the best solution to fix any intersecting geometry now usually when you add in a boolean cut blender has to find two locations to connect up the cut to in this case blender has to connect the cylinder cut to any sort of area on the cube in order for it to be a proper boolean so blender automatically chooses the closest vertex like you can see here but the issue with that is once it connects to that vertex it starts intersecting with the geometry because this edge here has to pass through some geometry causing these artifacts and like i mentioned already adjusting the bevel is going to make this less likely to intersect with other geometry we can take a look here when i adjust the bevel and make it smaller that little triangle where the artifacting is occurring gets smaller and smaller and then eventually stops intersecting right at this point causing no more artifacts now solely relying on making a smaller bevel is not practical at all because you don't always want a smaller bevel so in situations like this we just need to tell blender to have a better connecting point for these edges since this cylinder didn't have any geometry to work with the blender had to automatically create these two connecting edges in order for the boolean to work correctly but instead what we can do is add in an edge that the cylinder can already connect to one that's already available so what i'm going to do is tab into edit mode we're going to drop a loop cut down the middle here and then if i go back into object mode you're going to see that the cylinder has an edge to work with and it's a lot more optimal for the connection the cylinder doesn't have to automatically generate edges connecting to the cube because one already exists for it to connect to let's add in a few more cuts here what i'm going to do is add in a cylinder scale this guy down and place it right here in the corner somewhere maybe right about here will be okay i'll also sharpen the cube with hard ops and then we'll just give a difference boolean to this cube so i'll hold shift and select the main cube and then add a difference boolean now you're going to see this one went absolutely crazy because the connection points are not optimal at all so once again you could of course adjust the bevel and that will kind of start cleaning up but even in this case the smaller bevel still isn't working the best because these connection points are not practical whatsoever if you don't care too much about the location of your cut another thing you can do to fix up any sort of artifacting issues is to simply move the cut somewhere else and allow blender to find a more practical connection point so in this case what i could do is just move it over this direction a little bit and you'll see that blender starts connecting to some different locations on the mesh so i'm going to move it to i don't know right about here should be okay and you can see that in this case blender finds a lot more optimal connection points resulting in no artifacts occurring but of course we're not always going to have the luxury of being able to move our objects freely because sometimes we want to have the cut in a static location so if i was forced to keep my cut right in this location here if i wasn't allowed to move this or simply didn't want to move it i have to find another strategy to reduce these artifacts so once again i could simply add in a loop cut to the correct location i could put a loop cut right down the middle here so we'll tab into edit mode and then just line this up with the cutter piece maybe around here somewhere and then go back into object mode now you can see we have a much more practical connection point for this cylinder and it looks a lot better and in this case i can have a much bigger bevel before we start getting issues this strategy is also nice because we have a much more elegant wireframe view but what do we do if we put a cut on an n-gon we're not going to be able to add a loop cut through it because loop cuts can't pass through n-gons only quads so if i tried to add a loop cut through this cylinder for example you're going to see that the loop cut stops right at this edge here and doesn't pass through the face because this face here is an n-gon so if you ever have a boolean cut on an n-gon and you want to add in a loop cut to make some more practical connecting points all you really have to do is use the knife tool so in this case what i can do is like i just did adding a loop cut wherever i'm able to and now all i really have to do is connect up these two vertices i can either use the knife tool or just press the j key j is a lot easier now you're going to see we have a much more practical connecting point another way i could have accomplished that is by just cutting straight through the mesh so if i were to go into top view i could press the k key to activate the knife tool cut across by pressing c to keep it straight press the z key to cut through the non-visible geometry and then i can just click and press enter to lock that in and now you'll see we basically have the same exact effect here now sometimes artifacts are really difficult to deal with especially in situations like this where you have a lot of cuts very close to each other you can still do a lot to clean it up so we're going to do that first and then deal with the smaller areas obviously we have a very big artifact right here as a result of the stretch connections so let's give these cylinders a little bit of a more practical connection point so for this really big artifact it looks like that's happening because of the edge i dropped through this cylinder earlier so i'm just going to select this edge double tap g and then slide it over just a tad bit until that artifact is mostly gone and as you can see we've already cleaned that up pretty well but the connection points are still very impractical look at how stretched these are these do not look good at all so a much better location to add in some of these connection points will be straight through the middle here so let's go ahead and add a loop cut through the middle of these and same for these other three just kind of arbitrarily placing them and then we can go back into object mode and you're going to see that we have a much better connection point i'm still not a fan of where this edge is placed so i'm going to select it again i'll just use control and select down to there double tap g and then just move it over top of these i think it looks a little bit nicer that way so as you can see in just a few seconds we went from a very ugly and nasty wireframe to a much more elegant wireframe resulting in basically no artifacts occurring now sometimes after you clean up your artifacts you'll still have some really bad shading issues kind of like you can see here at this angle doesn't look good at all so to fix that we can just add on a weighted normal modifier to recalculate the orientation of the normals so select the cube go to add modifier and you can also do it over here if you don't have hard ops go to add modifier and then weighted normal and you're going to see that cleans up most of the shading issues as well so at this point you should understand kind of how to fix artifacts hopefully i didn't make this too convoluted i tried to make it as simple as possible but one final thing i must mention in this video is the weld modifier so sometimes you'll run into situations where you have these really close near miss edges if we zoom in really close you can see how this edge is passing through almost straight through this edge but not quite and there's a really easy way to kind of fuse those edges together to make the connection a little bit nicer and that's what the weld modifier so you've most certainly heard of the remove doubles or merge by distance command in situations like this where you have very close vertices usually what you can do is select everything and then press f3 and search for merge by distance and what this does is connects the vertices based on the distance so if i were to increase this a little bit higher you'll see that it automatically merges those vertices together into one single vertex the weld modifier does exactly this but without requiring us to adjust this geometry manually in this case we can't because we haven't applied these modifiers so the weld modifier is super useful for that reason because it does it non-destructively so we're going to go to add modifier and then weld and you're going to see just like that that edge has fused together and we have a much nicer connection so you can also adjust the distance of the weld modifier by simply dragging it up or down and my goal here is going to be to fuse this edge together with this edge so if i increase the distance you're gonna see that eventually it's going to fuse together just have to be very careful with it and as you can see this was the before if i undo that all of these were near miss edges and then after i use the weld you can see that those fuse together very nicely as a quick side note i forgot to mention make sure you put the weld modifiers above the weighted normals or else you might run into more shading issues like this if i put it above the way to normal they fix themselves now this might be an unpopular opinion but i simply don't think it's worth fixing artifacts 100 of the time sometimes if you have very small and minuscule artifacts that aren't really worth adjusting i think it's fine to leave them in your scene here's a very practical example if i zoom in i have a really tiny artifact on this model i created i didn't want to have to adjust the bevel or adjust the topology or adjust the location of this cut so i just chose to leave the artifact because it's so tiny and unnoticeable it doesn't really affect the scene and if i even go into rendered view you can see that in rendered view you can only really see it when you're close up but from a distance there's no way you're ever going to see that artifact and in cases like this i think it's fine to leave them now of course with that being said don't take advantage of this fix artifacts when you can it's going to make you a much more proficient modeler and you're not going to force bad habit if you want to quickly check for artifacts what you can do is go up here to the overlays panel and tick on face orientation let me turn my overlays back on and once you do that if you see any bad red spots that means there's a bad artifact there that you need to fix but if everything is blue then you're good to go i do have a few minor red spots but they're so tiny i'm not going to worry too much about them so hopefully this video helped you out and gave you more of an idea of what's happening behind the scenes when artifacts occur and how to fix them if this video helped you and you want to learn more be sure to check out my hard surface modeling playlist in my comprehensive gumroad course on hard surface modeling available for just 10 bucks link in the description thanks and i'll see you in the next video

Channel: Josh Gambrell

Views: 222,200

Rating: 4.9749126 out of 5

Keywords: blender, 2.8, how, to, fix, artifacts, hard, surface, boolean, glitches, glitch, shading, ugly, bad, holes, cut, topology, quads, remesh, remesher, tutorial, clean, cleanup, normals, bevel

Id: 0T3QdLJOBF8

Length: 13min 38sec (818 seconds)

Published: Thu Apr 23 2020

Reddit Comments

[u/WIDK-Producer]

Oh, excellent! Definitely one of those tips that is so useful it seems obvious once you know about it!