18 Ways to Speed Up Blender Cycles Rendering

all right come on lined up let's see what you got yes it finished one frame only 16 Alice okay so let's see per frame 16 hours for a 1000 frame animation should get done in about 6 months which is before Christmas yeah that's all right let's do it [Music] [Music] what what hey hello it's me it's you in the future I'm calling you from 2030 hi really because it looks like you haven't aged a day what behind me I wear a lot of sunscreen what can I say but listen you need to know render times are important yeah okay because if you spend too long rendering and you'll end up like me living in a box on the side of the highway poor desolate a piece of chewing gum on the soul of society I'm homeless right so because I rendered for too long I ended up homeless basically I spent so long rendering that well I was never able to develop my skills or than I was because I was rendering so much and then so I was never able to get a job also math ah right a copious amounts of meth I'm sure yeah oh listen this guy is going black again so I haven't got much time but I need to give you the advice that might just save your life it's the eighteen ways to speed up cycles okay well just email it to me or something can you do that no no in the future we don't have email it's all like cerebral up links it funny story actually it was the downfall of society like the nanoparticle base of the anus or collapsed low hey he's breaking up okay okay uh all right listen I'll fax it to you fax it whose could a fax machine yeah I know the hipsters they brought it back is dumb fun but I don't have one don't alright listen I just sent it we did but helpful you know the best kind of weird so that's what we'll do in this video we'll go over the eighteen ways to speed up cycles rendering these aren't well these aren't like a checklist that you must follow but they're sort of helpful tips you know if you want to shave off seconds or maybe you're rendering a big feature-length animation you know one of the first for blender and and you want to see how to improve it this is going to go over all of the ways that I know of how to do it so let's get to it number one reduce your light bounces light bounces what our light bounces ended well light bounces are something that happens in the real world and in 3d software so when light hits another surface it bounces off that surface and it will hit another surface it'll bounce off that surface etc etc to infinity in the real world but in 3d software that bouncing process is a very processor expensive task so you pay for that in your render times so there's a value in blender which will allow you to set the maximum the minimum and the maximum amount on light bounces that happen in the sink and by default it's set to 12 which I think personally is a little bit too high so for example this is a classroom scene which has 8 light bounces set at maximum right okay this is how it looks at 8 right now what I'm gonna do I'm overlaying a grid over here and we've got along the x-axis the number of bounces what I'm going to do is I'm going to cycle through these bounces here and in the background the render is changing with this graph ok interactive demo right so you can see that up until about 4 light bounces there's no difference no difference at all and that's basically my guess is there wasn't actually any extra light to bounce around so forwards the maximum and then after about 4 you can see 3 2 one you can see that the glass becomes opaque don't worry about that I'll show you a fix to that in a second and then finally zero down at the bottom there so zero there's a big change you'll notice the biggest difference between no bounces and one bounce okay so in my opinion other than the glass you don't need anything beyond one light bounce for this scene which means you can save a considerable considerable amount of time so instead of going from eight light bounces if you went to one you'll be rendering at 48 seconds instead of 95 which is a huge savings now I know you're probably thinking hey yeah but that glass looked really horrible there so we still want the glass to look nice well actually the the the settings over here these are the bounces this is where you would change it so these are the broad values here the maximum Amendment for the whole scene but you can also set it individually for your transparency and your transmission and all the different ones there so all you would have to do is just set these diffuse and glossies down to one and then just make sure the transparency is set to at least three or four or something like that and that would be it and you would be able to save a huge amount of render time while people don't know that what's a really easy way you can do it okay number two use portals portals does he mean these portals no not those portals I'm talking about blenders portals so when you are making an interior scene in blender which is like you know a room and you have a window in which there is light coming in through the window from particularly an HDR but any environment light basically you've got a lot of light calculation because it's actually lighting the outside of your room and then some of that light is going in through the window well that's that's wasted information right there's too much you know that that's being wasted there so what you can do is over the window if you place one area lamp and then in the lamp settings if you check a box that says portal what that will do is it will tell blender essentially where the window is so make sure that you get the light in through here and don't worry so much about the rest of it it's huge once you see it how lot of this so this is with no portals alright you can see very grainy I'm hoping you can see that in the YouTube compression but it's a very very grainy image now when we add one portal sorry to pause because there's two windows look at the difference from super grainy to almost completely clear okay which is crazy now you can see the render time does actually go up by 30 seconds which is not much so that's not really a fair comparison because really you know the whole point of a render is to get rid of the noise so if we were to without portals at all try and get it to the to that level I would have to double or probably even triple the amount of samples so just for this comparison to make it fair you can see that you would have to really go double or triple your render times to try and get it without portals so it's a huge saving so make sure that if you're making an interior scene or the architects out there watching is if you haven't learned about portals before and hopefully this will save you a lot of time in the future use them and yeah it's really really handy so again that's where to find it and I've got a tutorial in the description if you want to watch it but it's super easy to use all right number three use your GPU now some of you older blender users perhaps would say yeah come on everyone knows that well not necessarily especially a lot of beginners they will not know that you can actually with blender you can render with either your CPU or your GPU so there's most computers have to and generally speaking and this is excuse me when you get a drink that's where you change it you change it in the device setting right that you can set it to GPU um and if you don't see that by the way if you only see CPU there if you go to file user preferences system in the bottom left hand corner you should see underneath compute device something that says CUDA if you don't see something that says CUDA and your graphics cards underneath it then you don't have a card that is supported in blender right now AMD is not supported in blender so I mean that they're working on it I just don't know when it's going to happen so the video yeah you would see it there and generally speaking in the video you know gpus whatever they render a lot faster than a CPU so this is just one example here but you can see that it saved the render time of 33 percent and that's you know that's probably with a really good CPU as well so that's a considerable savings but the really really cool thing about GPUs and the reason that they're there was such a game-changer for the industry like five years ago is that you can add more graphics cards to your computer but you can't add more CPUs but if you wanted to upgrade your CPU you first of all won't get that much of a bigger difference over your last CPU but not only that like you can't put two CPUs in your computer at least not usually right so if you wanted to upgrade your CPU you would have to upgrade your motherboard which means you have to upgrade your RAM which means forget it I might as well just get on your computer whereas a GPU can be taken out and put into another computer no problems so it's a very easy investment if you want to have your render times you can purchase two graphics cards and it will render it in half the time because it's a linear sort of growth so three graphics cards for graphics cards is going to render four times faster than one graphics card card do so yeah it's it's a huge huge thing so make sure that if you've got a GPU and you can use it use it whenever possible number four change your tile size so this is another really important one that a lot of people don't realize is so important tiles what are tiles well tiles are when you hit the render key those little blocks that appear on the screen that slowly reveal your render those are tiles and the size of your tile is defined in the render settings underneath tiles x and y by default is set to 64 which is not really ideal for most people's whatever their their rendering on okay the size of your tile depends on whether what whether you're working on a CPU or GPU the tile sizes should be different in fact the exact opposite so if you're working and you're rendering on a CPU the smaller your tile size the best coming in at about 16 by 16 pixels the better it will be if you if you go larger for CPU the worse it will be and on GPU is the opposite the larger your tile size the better the renderings will be so you could see that you could considerably like if you accidentally were rendering out a really small size on the GPU you could take forever to render the scene because it's you've got the wrong tile size right so you can have huge memory sorry render time improvements just by changing the tile size as a general rule of thumb smaller tile sizes work better for CPUs I just use 16 by 16 every single time works for me and the bigger tile sizes for GPUs maxing out at about 512 by 512 generally speaking is better now different GPUs different tile sizes will work but I've heard that like different architectures for in a video like a Kepler card or a Tesla card some of those use better with like rectangle shapes I don't know why but just when you get a new card just do some tests and figure out what your optimal size is for your card because that will save you a lot of time in the future all right so gotta get another drink here I think his office is really dry that's right in raspy alright number 5 reduce your samples yeah you might say duh you go to reduce your samples but ok first well what are samples I know all you do but let's talk about samples samples most of you know as that grain that appears over your image ok so the whole point of rendering is to try to reduce that grain and you do that by increasing your samples which you can define in your render settings right there so obviously the higher the render sample amount you set it to the longer you'll render times are going to be but the clearer your your final image will look so basically you want to try and set it to a higher value for your final render and yeah but the problem is is I see a lot of people using incredibly high sample amounts to the point that there's no point in doing it that high so for example here is a scene set at 10 thousand samples and here's the same scene again set at 2500 samples one quarter of the number of samples before now as I flick back between them can you see a difference no you can't because it's indistinguishable to your eye you can't see any difference between them and yet the 10,000 sampled one took most of the day to render and if you had 2500 rendered in less than an hour and a half so huge time differences there but very very little difference between the actual images so there's a point where the samples that the point of going any higher is pointless so you weren't trying to find out what is the optimal amount because while this might sound like an exaggeration like who would go to 10,000 have a look on Blender artists you'll see some people that are rendering their scenes I've seen some with like 50,000 samples and they said they let it render for 48 hours thinking what are you doing there's no reason to go that high that's just insane it's just a waste of power a waste of your time more importantly and it just should don't go that high okay keep it keep it as low as it needs to be speaking of noise and samples there is a new feature in blender 2.79 called denoising and it is going to be a game changer now I only just played around with it for a little bit but I'm going to show you here what it does denoising does this it takes that grainy image and then it applies a like a post-processing step I believe on top of it which will make it appear clear and smooth out so it's a big deal and it's going to be a huge deal for the blender community once once everyone sees it explain what this is this is going to make a lot of difference you're going to see it from now on like in the future most renders are going to be using a denoise ax because for example here is my bathroom scene and I'm hoping you can see it in the YouTube thing but this is a very very noisy image very noisy I would never use this as a final image however when I applied the D noise filter on top of it it looks like a final render it's amazing I I don't I don't properly understand how it works ago haven't really researched it that much what it it looks like black magic it's like sorceries like so yet okay now the difference between these two here you can see that the denoise instead applies a small like it is it does actually add something to the Brenda but again it's not a fair comparison to say that the denoise one took longer because the whole point is to make a clear render so it's saving you let's say if you had to double the or sorry quadruple the rendered time it's saving you considerable amount of time especially for animations like like I can I can now looking at this I can say like wow I can finally do an architectural animation now because before like interiors are just horrible just noise absolutely everywhere but with this it's going to make it possible so I'm really really excited about this feature I think once the community seeds are they're going to go ballistic but yeah try it out it's it's really fun in 2.79 it'll be it'll be in there for everyone I'll probably do a tutorial on if people want it but they go alright number seven this is one not a lot of people don't realize but you should be using the latest blender version because there are big differences between all the versions of blender and newer versions pretty much every newer new version of blender they try to improve on the render times of the one before it and they're always doing improvements so this is I did this one a couple of years ago but comparing two point six four to two point seven one basically like a year of releases there you can see considerable time savings and this is for both CPU and GPU CPU especially they've been able to really crush the render times in each consecutive later release so it's it's it's just going it's going crazy so make sure that you are using the latest version sounds like a no-brainer but you know I still see emails from people whether like hey I'm you know I'm using two point six six so I don't have that feature and I think wow why why like a well you know I just that's the one I've got so I don't I like how it works so I don't want to install the latest one like you can do that and you know I'm all for making life simple but you're going to be paying for it in your render time so make sure you're using the latest version please um again I haven't done it for 2.78 where we're on now but yeah it just it's going down okay all right number eight this is an interesting one a lot of people don't realize what actually different operating systems and by that I mean you know Windows Mac Linux they have different rendering times because it is supported on every platform which is fantastic most software you can't do that but there are different times between them so here I've got two tests just testing between Windows and meat which is Linux a Linux distribution and you can see that for GPU there's almost no difference in fact in most examples I've found Windows performs better on Windows sorry GPUs perform better on Windows than they do on Linux however for CPU Linux kills its OCP so Linux is really good at CPUs not as great with GPUs because I think they put a lot more effort into the drivers for Windows because there's game is on it obviously but yeah it's really good with CPUs so that's just something to keep in mind I wouldn't just immediately rush out and go and get Linux don't feel you have to do that all that you're missing out because you're using Windows I've known about this for years and I use Windows and that's just because it makes my life easier because that's where all the software is I can play games on it as well and it's just I don't see I'm happy to eat the render time but you know hardcore people out there if you really want to cut down on the render times this is why a lot of render servers by the way if they use Linux because it's just optimized and just perform so much better so yeah you might be wondering hey Andrew what about Mac where's Mac fit into that I have no idea I'm going to throw it to you guys do you guys have a Mac that also has Windows and Linux because I search for online and I didn't see anybody that had one like a triple boot system so if you do it'll be great to test out the render times between them I'd like to see it yeah post it in the comments if you do it alright number nine clamp it hmm what do I mean by clamp it would you like to know clam but what's clamping other than that meaning a clamping is okay so you know sometimes when you render a scene you see in the background you sometimes see these tiny little flecks little tiny grains of light okay those are called fireflies and often times no amount of extra rendering like increasing your samples will get rid of those so you can't get rid of those fireflies sometimes they just they're they're usually caused by small light sources or caustics or a bunch of different things but you can get rid of them by changing your clamp settings in the render settings there I will say you this should be used as a last resort and I'll explain at the end why but it can be done so say for example you have this teapot seen here and you can see that in the background there you've got a lot of grainy noise okay well if you had to clamp it you can see that it goes away immediately so this is without clamping and then this is with okay big change so that's that's going to save you a lot of time because you don't have to use as hire a sample amount so that's that's a huge improvement there now again that is where you can find it the clamp direct and indirect however I say use it as a as a last resort so to me I use it like a get-out-of-jail-free card if nothing else works that's when I do the clamping and the reason I don't use it all the time is that by clamping it's going to bring down the values of yes the fireflies in the background it will clamp those values down but it will also clamp down every other value in your scene so you can see with this teapot here difference between them I'm losing some brightness in the rim there because when I clamped it I had to I had to get rid of some of that brightness in the teapot which I didn't want to do but I had no choice so that is something to keep in mind just keep it in mind generally also zero is turned off and then the higher the value the better because the higher the value is going to allow more light values to get through and then you just turn it down gradually and see when the fireflies disappear and generally speaking you only want to use indirect not direct but yeah it's up to you so like if you have like light shining in on the floor that's a big part of your scene if you just clamped it you're going to lose all that brightness in the in the floor so that's why I use it sparingly number 10 speaking of fireflies caustics the largest cause of them so caustics for those who don't know are like if you've got a glass of water on a table the light shines through it you see that weird little like light pattern that appears on the table that's refractive caustics you can also have reflective caustics which is when light bounces off a surface onto another surface and it creates like an interesting light pan so those are two different types of caustics and they have very process intensive forfor a renderer right and they often cause more problems than their work so there is two little checkboxes in your render settings enabling you to turn them off and sometimes turning them off can save you a lot of time so for example this is an image of a glass of water on a table or floor I guess that's a big glass of water let's be honest um but you can see there you've got that nice light shadow on the ground there but if I was to turn it off you can see that there's no light shadow however the render times were a lot faster so this is the difference between the two they're 31 percent faster without the caustics however you could argue that the whole point of this scene is to see the light shine through the glass so you would obviously want to leave it on but honestly for a lot of scenes it's just it's more trouble than it's worth and for probably 95% of all my renders I've ever done I just leave it turned off because it's just so commonly the cause for those fireflies to appear in your scene I just don't like it and I just I don't see the point in most of the time so I usually leave it turned off but they go okay so number 11 let's talk about object instancing what is object instancing so say you have one tree like this right and you want to make two trees so you take that tree you hit shift D and you duplicate it now you have two trees however as well as two trees you've also double up on the amount of memory you've used and your render times as well because it has to now cache that mesh essentially so by duplicating it I have doubled the amount of information in the scene not so great especially when they are an identical tree so what you can do is you can use object instancing so that they share the same object data so for example with this with this leaves here so likely to five select these other leaves shifts like then hit ctrl L here underneath make links if I select object data now up here in the object data panel you can see that next to the object there is now a two number next to it because there are now two objects using that same object data and you'll know that they're connected because if you were to edit one of the meshes like say and make that all the way out there then you can see that they both have that change okay but you say okay but I've got a number of different objects here okay I've got I've got three branches I've got a bunch of different stuff going on I don't want to have to do that every time I duplicate something well if you want to duplicate something but you want to keep that object information if you use alt D alt D instead of shifty the same thing happens you've duplicated the tree however it automatically made them share the same object data so this means a lot for your final render so this is very simple scene with a bunch of trees on it and this is with them set to single users meaning I duplicated them the wrong way I did shifty instead of all T okay they're all spread out there okay you can see that the rate of times two minutes 42 seconds and 6 gigabytes of RAM which is incredible amount however if it's instance I have the render time and I've proven I decrease the memory used by a hundred times almost just by using instances instead of actual like single objects for each one so huge savings there and I'm ashamed to say it took me like six years of using blender before I even realize that object instances were a thing so don't feel bad if it's the first time you finding out about it I'm hoping in some use to a few of you out there so use that and you'll save a lot of render time and memory which means you do more likely you can render it on your graphics card so anyway there you go cool now let's talk about adaptive subdivision mmm sounds technical well this was something that again is very new featured on it came out I think in the last release or two but what allows you to do is say you haven't a scene like this where there's a lot of depth in your since you've got stuff that's in the foreground you've got stuff that's in the background so a lot of nature scenes interiors all that kind of stuff they have this going on well the detail that you need to see in the foreground is different to the amount of detail you see in the back the background you can get away with very low poly objects but in the foreground you want to have higher poly objects so adaptive subdivision allows you to do that you just check one box in your modifier settings there to use the adaptive subdivision and now it will subdivide it depending on how close it is or how far it is from the camera and that has big savings for your render times so check this out this is whether it turned off okay renders in 21 minutes uses 12 gigabytes of memory now with it enabled it's 14 minutes and it's used a fraction of the amount of memory ok huge amounts of saving this so this is why I was so excited when it came out I made a whole tutorial on it by the way if you want to see it it's in the description you can check it out but it's such a huge feature so yeah it's really important so especially for nature scenes do make sure that you make use of this new cool feature number 13 remove alpha transparency so this is you know fairly seam specific now we're getting into but this is a big one so what is alpha transparency so this is when particularly when you're making trees or plants or anything like that sometimes you want to have a leaf and the leaf maybe has like interesting little bit on the like really bits on the outside there and you want to make sure that it has that frilly bit in the render so you can actually the alpha channel of the leaf so that it has that nice filly pattern there as opposed to if you were to just model around it you know in a blocky shape you wouldn't get that pattern there so it looks nicer with alpha transparency however you pay for it in render times significantly so here is a tree with alpha transparency it took 29 minutes to render without alpha transparency the blocky method it's 16 minutes to render almost half the render time and honestly there is very very little difference between them indeed in the final render you can actually see like a bright green outline there but that's only because I think it was just as an example on this render to show you where it is but you shouldn't see that if you've modeled this correctly if you were field making a tree I assumed to say I didn't even realize it and I was making trees for ages I thought that using alpha transparency was the way to go cuz it makes a better looking leaf and I didn't realize it was adding anything to the render times but significant amounts so just crazy so make sure that if you're making a tree or a plant that you are using the blocky leaf shape and don't worry about the Alpha transparency because you pay for it's just too expensive so forget it all right number fourteen reduce the strand count so again very nice depends on you scene but strands basically it's the particles so it could be grass it could be what could it be it could be hair on a character's head or it could be rug on a land room floor it's a very expensive thing to render all that every single one of those particles so you pay for it so this is with one hundred and forty five thousand particles with five children strands for each thirty-six minutes sixty-five thousand however is 26 minutes so there's a big difference between that and you know you might think you know maybe it's not that bad I might go with the extra you know 145 and that's fine you can do that but just know that the more strands you you add into it the longer you're going to be paying for it a lot of people don't realize and they try and use like a long million particle ground or something like that and then wonder why they can't render so just know it's a very intensive task does it get another drink here guys number fifteen coming to the end remove volumetrics volumetrics what i volumetrics where you might already know what it's like fog it's when the light shines through something or it's just fog in a scene right so this was a new feature well new ish two or three years ago they added it but you can now render volumetrics which is very very cool it's also very very expensive in terms of rendering so here's a scene with volumetrics very cool scene and here is it without volumetrics obviously width looks a lot nicer and that would that to the whole point of this scene was to show off the volumetrics bite um you can see that it does add significant amounts to the render time about forty percent almost extra and it looks a lot looks a lot grania as well and my throat is as well so you have to you have to be aware like when you're building a scene know that when you if you're just going to add some fog or whatever if it's a tiny little bit of fog like do you really need it because you're going to be paying for it with your render time so use it when necessary sometimes for this scene it makes a lot of sense but your scene just consider it okay so number sixteen speaking of things to cut you can also cut the sss which is subsurface scattering so subsurface scattering is something that you might have seen if you hold your hand up to the light or if you're talking to somebody in the sun lights behind them you see it through their ears but it's light as it are traversing through an object it will shine through on the opposite side that's called subsurface of scattering um and there is a special shader for that in your node settings so yeah basically if you're making a character that's really the really the only time you use it another example might be food like a glass of milk or something you can sometimes get it there but mostly just characters yikes Syntel the sequel since L my precious you forget you forget how good hair looks until you you don't have it anymore right I'm sure a lot of men have realized that with SSS you can see it renders in four and a half minutes but if you use no SSS at all it's a fraction of the time so it's a very expensive shader to use so I would agree that it does actually look better with subsurface scattering if you don't use it for a character that the skin sort of looks waxy not waxy it looks like like hard concrete or something like you really need some light to be passing through it so yeah I would say you do need to use it in this case it is a lot to pay for those so you know you know when useful you can use it otherwise wise done right number seventeen enable M is what is M is you might ask it looks like mi5 but it is not the same multiple importance sampling is what it stands for it's in the world panel right down there a little checkbox sort of hidden there and there it is what does it do well if it's turned off it might your scene might look like this if it's turned on your scene might look like this now this is really only applicable if you have lit your scene using an HDR environment light because I believe what it's doing is it's taking it from you know an HDR with all its thousands of pixels and trying to find the light values of each one and I think when you enable it tries to average it so you don't get that noisy some parts dark some parts bright sort of mess going on it tries to average it I believe don't quote me on that but it has a huge huge impact and yeah I believe it's now turned on by default but it used to be like this hidden secret that some artists knew about and when they turned it on they were like whoa my scene looks so much better but now I think it's turned on by default so it's not as cool anymore you can't impress too many people with it for a while you could so if you if you are rendering with an HDR got to make sure that that one is checked otherwise it's going to look awful I mean basically it looks broken if it's if it's not enabled so that's I mean it really shouldn't be called a performance improvement it should become like is it right yes or no with it checked it is correct and so anyway finally the last one to leave on because there was 18 cycles improvements we're going to talk about these are the small performance improvements which you can find in your render panel underneath performance so these are the used spatial splits you use air BBH use so save buffers and the persistent images now here's the thing maybe you might notice this as I was cycling through it but in these examples I didn't actually find for these check boxes to actually make an impact the first time we ran these tests we were able to see an improvement we did it for a different scene and we rendered like one frame then we stopped at another frame and we were able to see an improvement however I and then I recorded the start of this video and I call it the 18 you know ways to improve cycles or whatever and now then I did some retests halfway through you know doing this tutorial and then I wasn't able to reproduce it my point being is that these small performance improvements supposedly are supposed to improve the performance of cycles but I haven't actually found that to be the case I found it to pretty well stay the same whether they're boxes are checked or whether they're not checked spatial splits I've been told are supposed to increase your memory slightly with a decrease in render speed I didn't find that I found that render speed was about the same by the way if you see like two seconds plus one or two whatever factor that is zero improvement or change because the system if you rerender I think twice without changing anything it can usually come within a hair of that anyway so it's basically the same no difference use hair dvh maybe five seconds faster with more memory it was actually supposed to be when you check it use hair DBH it's supposed to use less memory so I found it to be the opposite way with that one not great but I did I spoke with Andy Krawczyk on Twitter and he said from he third from Co gay that this is really only impact it really only impacted if you've got motion blur so say you had grass blowing in the wind like that and there was motion blur oh for agent three to seven his hair was moving or whatever and apparently that really really taxed the render times so this was supposed to solve that or it should solve that right but I wasn't able to replicate it sorry to say I really yeah I wasn't able to do it save buffers I've since learned Andy told me that this is actually was really only applicable to the render the blender internal rendering engine and that cycle that won't make much of a difference which explains why I wasn't able to get much of a difference from it it was supposed to case your image textures somewhere so that it's been able to reference them faster for your extra frames then on I didn't find any improvement and then we've got persistent images which I think also might be the same like it doesn't apply to cycles that could be wrong on that but I wasn't able to find any improvements so yeah so these he's I mean I feel bad ending on such a low note like I wasn't able to to replicate this stuff but I do want to Inc include it because it looks so important and you see this stuff in the performance settings and you probably wanted like I wanted what do these buttons do should I leave them checked check on checked off does it am I paying for render times because turned on or because it's turned off honestly in my opinion it doesn't make any difference probably nine times out of ten the scene that you're rendering is not going to make any difference when you're doing a production like they were doing for agent three to seven you probably come across like one or two frames where it just crashes or you get horrendously long render times for this specific object and that we're having a guy like Sergei the developer on your team to go oh you've got to check the head VDH box right that's when it's applicable but I think for the everyday artist I mean this should really be hidden almost in like the user preferences because that I feel like it doesn't make that big of a difference to anyone in my opinion that's just my opinion but yeah alright we discussed a lot let's round it off we discussed a lot in this this little video the summary is on Blender guru comm you can click the link below that's what it says behind my shirt and microphone link is below so I'm going to put the whole summary up there with images and everything so you can just reference it in the future you don't have to listen to my voice all over again you can just reference it on there now if you look at this and you think boy Andrew that sure is a lot for the user to take in like why don't those stupid blender developers pull their head out and turn this stuff on by default or make it automatic or something like that here's why you a lot of these things you might seem like a no-brainer like hey the everybody should be using GPU well not everybody has a computer that supports GPU a lot of features don't work with GPU so having it on by default isn't a good idea other things like portals how would blender know whether you've got an interior scene or an exterior scene where the lights coming from etc some of these things you just have to it's when you're building the scene it's only the artist that's building it that can know that this particular thing is is useful yes it's true some of this stuff you would never know unless somebody told you but I think that's part that comes with the territory some of it is becoming automatic like for example use optimal tile size Taunton told me that that's going to be in two points two point eight or two point seven nine right uhm yeah that's going to be automatic so hopefully you shouldn't have to touch that in the future and there's all stuff like use denoising you could argue that should be an automatic feature but you could also argue the other way that it those things in you know so you might not not every artists need to know by default so the whole like default argument isn't as clear-cut as it sounds so some of this stuff you do just have to know so that's why I'm making this video because it's a common question a lot of people have how do you improve render times and some of the stuff you just don't know until you find it so and the other thing is is that a lot of these things here you don't have to do every time you make something it's just like some of this stuff like volumetrics sss object interesting all that stuff that's stuff that you once you know it now when you make a scene in the future you'll know like oh if I add fog to this I'm going to pay for that dearly so I might not do that or something like that like you don't have to go through a checklist every time you render a scene or maybe you'd want to do that anyway but yeah you can just ya know about it so as an example this is the scene that I started with on the on the first slide let's talk about let's say I finish this scene and now I want to do an animation I want to make the camera fly through the scene now if I was just doing a stool I probably wouldn't worry about doing all 18 of these I would say you know if I can render it who cares I'm just going to render it overnight I'm going to come back it's going to be fine if I'm doing an animation it could mean the difference between a two-month long render and a 5-day render or a five-hour render I don't know animations are so like it's just obviously it's multiplied exponentially what is it exponential whatever the the performance improvements you can make like even down to fractions of a second can have big impacts over a you know feature-length film so for something like this I would go through my checklist and I would say all right looking at my scene here can I reduce the light bounces yes doesn't need portals I will make sure I use my GPU if possible make sure I need any optimal tile size I don't want you to worry about clamping or reducing the samples cut the already optimized denoising yes I want to make sure that I smooth it out instead of you know having heaps and heaps of samples make sure I'm definitely losing he displayed devotion that's just a no-brainer object instancing absolutely if I had for all those duplicate cherry blossom trees there if each one of those they were individual single user objects I probably wouldn't even be able to render it it would be so overblown in the memory so definitely make sure I'm using that adaptive sub dip definitely for the ground and rocks and things like that I want to make sure I'm using that alpha transparency absolutely make sure that's eliminated for all my nature objects because that's a very common scene where you would see it strand count make sure I'm using the lowest amount of grass possible volumetrics that here's an example of like volumetrics like youth there's fog on those mountains there do I really need true volumetric fog or can't get away with and doing it in the compositor like a fakery sort of thing where it's not entirely accurate but I wouldn't be paying for it as dearly doesn't need SSI because it's 70 people and it basically MSI turned on yes if I'm using HDR and those small performance improvements right that's that sort of the checklist that I would run through as an artist if I was doing an animation not every single scene that I make I go through this it's not like you know flight manifests you have to go through all the checklists before you take off or whatever it's only if you absolutely need to give me a like now thank you for watching essentially this is the end if you found this useful do give it a like and I do want to end by saying thank you to these people Mason Menzies actually did a whole bunch of the tests basically most of the tests that you just saw a painful job rendering for two hours coming back rendering again but he did that so thank you to Mason the blender foundation for providing the CC source files mic pan Christophe SUSE Nick Brunner and MRIs provided some of those render time tests benchmark scenes and then Rob Garlington for the artwork for this tutorial but that's it thank you for watching hope it was useful and yeah sent it to anyone who's got terrible render times thank you for watching see you next time bye

Channel: Blender Guru

Views: 1,078,902

Rating: 4.9679279 out of 5

Keywords: blender, tutorial, cycles, rendering

Id: 8gSyEpt4-60

Length: 47min 30sec (2850 seconds)

Published: Wed May 24 2017

Reddit Comments

[u/ONLINEMAN_]

I'm curious, does the new denoising feature use some 3D information from the scene ? like textures or geometry to know where not to blur textures or hard edges.

I haven't tried it yet but the stuff i've seen so far is pretty damn good for noise removal...

And, awesome video as usual :)

[u/JSMOZART]

This video was actually super useful, thank you!

[u/realpudding]

very useful tutorial!

I would add, that if you are rendering an animation, you can generally get away with a bit of noise, when the noise pattern is animated aswell. because of the moving images, the noise won't be as noticeable.

and I found (through personal testing), that using a lens distortion node with 0.01 distortion can also reduce a bit of noise, because the pixels are interpolated when the image is distorted. and the distortion is so minimal, that it's not really noticeable.

[u/EZvidz]

Any one here using a GTX-460. Because Cycles realtime and production renders realy slow. Oh and uuh... i have a Intel QuandCore Q6600 with 6Gigs of Ram.