BETTER PERFORMANCE in Blender with the Decimate Modifier!

what's up guys justin here with the cgessentials.com back with another blender modifier tutorial for you today so in today's video we're going to check out the decimate modifier this is a modifier that allows you to try to manage the size of your models inside a blender by letting you reduce the number of edges and faces in order to make things run more quickly so let's go ahead and just jump into it alright so a lot of the time what can happen is let's say that we were to duplicate my body model in here and we were to add a subdivision surface modifier like this one and let's say that we went pretty heavy with that maybe something like three and let's say that was applied so a lot of the time what will happen is people will subdivide models so that they have more edges and faces than they really need and so let's go in and let's turn on our statistics overlay so we can take a look at this so if i hide my body model right now that was subdivided you can see how this object is fairly low poly so it's got a low number of vertices and edges in it but when we subdivided that bonnie model notice how you've got a lot more edges and surfaces in here and so what that means is that means that we just have more geometry in our model and that can get really big we'll look at another example of that in a minute and it can really negatively affect your performance well the decimate modifier is a modifier you can use in order to reduce the number of polygons inside of your model and so the way that that works is you can just click in here to add your modifier and in this case we want to look for the decimate modifier so when we do that what that's going to do is that's going to give us a couple different options in here so first off there's three ways that you can reduce the number of polygons in your model there's the collapse the unsubdivide and the planar and so you can see more about this on the blender manual page which i'll link to in the notes down below but let's just take a look at our options so the first is going to be the collapse option the cool thing about the collapse option is you can basically tell it a ratio to reduce to so you can click and drag this slider in order to reduce the geometry in our model and let's go ahead and let's turn on our wireframe so that we can see what this is doing so notice how as i drag this this is basically going through there and dividing the number of faces in your model and you have to be kind of careful when you do this because if you go too far then you just get like nothing in your model anymore but um the ratio makes sense in the sense that if i was to type in 0.5 it's basically going to reduce the number of edges and faces in here by half and so this is good for models that don't use like quad geometry and we'll take a look at another one of those in a second but it's not necessarily as good for this model because notice how i'm getting some like pinching in here and my materials are a little bit messed up for this model we might want to take a look at the second option which is on subdivide so what unsubdivide is going to do is it's basically going to use an algorithm to come in here and try to unsubdivide these surfaces and kind of redo the mesh using the same kind of math that we use with the subdivision surface modifier and so you can adjust that by changing the number of iterations and i noticed that i retained things a lot better on the even iterations so if i go to like one or three for example notice how i get like the triangles in here um with these faces so i usually find that i'm getting the best results in like two for other things like that but notice how for the most part and there's a few exceptions but for the most part when i unsub divide this object this is still maintaining the proper material locations a lot better than it was with the unsub divide or with the collapse function all right and then finally this last option planar will come in here and it'll divide the planes by angle or to divide your faces based on a certain angle so you can adjust this and you can adjust this based on several different options right you can do it by uh normals materials seams etc but if i drag this notice how what this is doing if i do this by normals is that's just coming in here and that's just dividing the faces up or it's putting the faces together based on the angle but if i do it by material you can see how this comes in here and this actually checks the object and face material and it kind of retains that a little bit better so this planar option could be good if you have something that has a lot of complex materials that you don't want to lose so i think a lot of the time most people use the collapse function more than any but yeah and so let's take a look at a practical example real quick so this is a model that i've downloaded from sketchfab so it's like a it's almost like a 3d scanned version of a model right you can see how when i bring it in i get like 277 000 vertices so it's pretty heavy model credit for this this is a sketch fab model that i've downloaded it's the louis the 14th defense from the louvre in paris and i hope i said all that right but it's uploaded by huang hep vu and i will link to some notes down below so you can download it and follow along if you decide that you want to do that but if we uh take a look at this model and let's turn on our wireframe for a second so you can see how this is a very heavy model right it's all triangulated it's just got a ton of faces in it and first thing we want to do because we need to apply the join modifier to the whole thing so let's take this whole thing and select it and just do a ctrl j to join it but if we look at this you can see how this is really heavy if you're doing like game modeling or something like that you probably don't want it to be quite this heavy so what we're going to do is we're just going to apply that decimate modifier right here and so let's say that we wanted to bring down the number of polygons in this by half well we could just select collapse i'm just going to type in a value of 0.5 and hit the enter key well what that's going to do is that's actually going to divide this by half so you can see how with the number of edges in here those got cut in half and if we go back outside of our wireframe you can see how this has the same look but has a lot less geometry so if we go do like a 0.25 you're going to get something very similar right so it's going to reduce this but notice how you can't really tell the difference the reason you can't tell the difference is because in this model the detail is really being created so the general shape is being created by the vertices and edges that are in here but the actual detail when you turn off your wireframe is really coming from the image that's applied to this so you can really reduce these in size to make things run a lot faster using this tool especially if they already have detailed materials applied to them inside a blender so that's from in this video leave a comment below and let me know what you thought was this helpful to you have you used the decimate modifier i just love having that conversation with you guys if you like this video please remember to click that like button down below if you're new around here remember to click that subscribe button for new blender content every week if you like what i'm doing on this channel please consider supporting me on patreon every little bit helps so make sure you check out that link in the notes down below but in any case thank you so much for taking the time to watch this i really appreciate it and i will catch you in the next video thanks guys

Channel: The CG Essentials

Views: 42,648

Keywords: blender, blender 2.82, blender 2.8, blender modifier tutorials, blender tool tutorial, the blender essentials, the cg essentials, thecgessentials.com, justin geis, justin geis blender, blender 2.9, blender 2.91, Blender modifiers, blender modifier tutorial, blender decimate modifier tutorial, blender decimate modifier, blender decimate modifier performance

Id: N4QY-1Vf6LM

Length: 7min 21sec (441 seconds)

Published: Thu Feb 18 2021