How to make a fake Exponential Glow in Nuke

well my name is zu Guetta and this is you goes death welcome to another episode and you just have to be better today we're going to talk about glows and fires which is I want to show you a little trick that I've developed over the years after doing a lot of game cinematics so I've done this kind of trick on pretty much every cinematic I've done and especially good when you're using fire elements like you know elements from stock footage or if you using fire from 3d as well I have done this successfully on the body-count cinematic I've done it only just for a cinematic I've been up on the home front cinematic on the rifle Kingdom cinematic I think I'd use this kind of technique for almost every project I've done and this is what I call a two or three step glow because usually the glow that you have default in new for in After Effects or any other application is usually enacted enough and most of the times the CG and elements that you get from fire they're a bit dull they don't have a lot of dynamic range so you kind of have to treat them to make them really punchy and look like fire so I start of course I would love to have your support so please feel free to subscribe also please feel free to follow me on Twitter at you go see Guetta and of course last but not least please support me on patreon of course these tutorials all free in YouTube but I would love to be able to make more of them I would love to be able to do them weekly instead of once a month like I've been lately doing this is of course all to do with my work I'm always very busy directing cinematics and doing trailers and visual effects so of course I have to put the tutorials on the back burner the more support I can get in patreon the more it will help me to actually make more tutorials for you guys I'll be using some stock footage from action of the effects if you guys want to check it out action VFX has really high-quality stock footage most of it is infrared but you can also have access to the red footage which is really cool and so as you can see here you can actually download most of the files in both Perez and also in red files so that means you can actually have access to the full dynamical engine file now this is the file we're going to use today this is a piece of fire called ground fires or one it is an actual original a 4k clip I have of course reformatted and corrupted and transformed it so that we can use it for this tutorial is it's a bit heavy for us to actually use it in 4k so it's probably easier to just do this so one of the things that I wanted to show you is that this is like a little small trick because a lot of times people tend to put glows and fires you know because it's normal because if you look at how fires look in the world like especially if you look at you know if you just google this night fire you can kind of see that fires during the night do have a lot of glow so you see for example if you look at this image you can clearly see that there's like an enormous amount the glow and this has to do with the fact that fires have a spill of light and it has to do with the exposure of the camera so if you're exposing to the actual surroundings like these trees and of course the fire is going to be completely overexposed and if you expose to the fire then you see the fire in much more detail like you see on this picture here so it's always a bit like a hit and miss like you either expose to the fire and then you get the nice detail of the fire but no glow but on the majority of shots that you see in film you're exposing to the rest of the people so when an explosion happens you're supposed to have an overexposure that's supposed to be like that that's the idea tends to be that most fires that you get on stock footage or even in 3d they tend to look a bit dull they tend to have this kind of look you know they of course because they're trying to shoot it with the most dynamic range possible so you can actually use it to your advantage in djenne if you want you can actually expose up or you can expose down and have all that nice detail and just so you can kind of see the amount of detail the action of the effects footage as just look at this like if I lower my apps top it still has every single bit of detail even if you look at the earth the vectorscope nothing has been lost or clamped although on the vectorscope it looks like it's been clamped it hasn't so it's so this is really high-quality stock footage and it's a bit grainy but you know nothing that you can't like the noise and actually fix but you know this is not really the purpose of this tutorial the whole point of this tutorial is talk about the glow so what I tend to do is I tend to kind of like have this kind of two-stage glow because people tend to have the idea that it's just going to put a glow on top and so they what they usually do is they put a glow like so and so when you do this you get this kind of like really fake looking glow of course this is a default the problem with that is even if you start messing around with the tolerance even if you start messing around with the actual brightness of it and even the size of the glow there's just so much you can do because it looks very CG ish it looks very fake the reason for that is because glows usually tend to have a very big outer glow and it has an inner glow and they kind of require two different tolerances and also not to mention when you're using a glow like this and you're using affect only and you're trying to apply the glow on top of the image the glow node is actually doing a plus operation so all of your highlights you know if you look at the fire here for example I have values of two one zero two when I put the glow I start having values of three two zero three and that means it's multiplying the fire by an enormous amount of values you kind of don't want to do that you kind of want to control the glow to have a scream now a screen operation is not a plus operation so with all that in mind let's let's see how I would actually go around doing this so I would of course delete the fire we have and I would start playing around with the notion that we would have two fires so let's say that we put you know the glow here and let's just make a separate stream for the glow so the whole point is this would be you have your glow I'm also going to open up this globe and this is going to be I'm just going to call it the outer glow and I'm going to set it up to effect only so that I only have the glow itself then I'm going to put a merge node I'm going to actually make it as a screen operation and I'm going to apply it on top of my image and so now I'm applying the glow on top so I'm going to sample that same area and I'm going to have the glow the normal the glow we were doing so if I apply the glow just as it is with no effect only and this is direct on top of the image you can see that my glow values or getting around 3.3 you can see here on the actual values 3.3 2 point 1 and 0 5 now if I use the same values but instead of using to see the difference really is enormous like if you look at how the screen operation handles the glow and how the other goal gets applied you can kind of see that not only my values are getting multiplied beyond what is reasonable with the footage you have not to mention that you want to keep the values on a reasonable amount so that people can do color correction properly and you know you want to give this to a great artist in to a colorist and still keep it as it should but you can kind of see on the vectorscope you see how much it crunches the highlights on the top there you can clearly see them here how this is really going wrong and you can even see it on the vectorscope how much it's breaking the values so my advice is always never use the glow directly so you always use that as a screen operation so this of course is the first step which is the outer glow and that's why I'm calling it the outer glow now the outer glow is similar to the image that you can see here on this fire you see it's kind of the majority of the glow that is very dull but it actually lights up the whole scene around it I'm going to do that I'm going to just go ahead here and I'm not going to really play around with the tolerance as you know here on the glow what happens is the tolerance is kind of like the luma key for you to control how much light you want on your image and of course I'm because I want to do an outer glow I'm not really going to touch the tolerance I am going to of course touch the brightness brightness of course just making it brighter and brighter that's just the name says the saturation I'm going to leave it for now and I'm not going to use a which channel the way channel is really useful when you have CG and objects is you can use masks in CG like an object ID to have the glow only being effected on that area it's really cool for that but that's not the purpose of this tutorial for today I am going to use a huge size on my inner ghost let's let's try a really extreme one so I'm going to go with three two hundredth for now and you can see you have a really cool image now going on here on the waveform you can we we tell how much you're blurring by just looking at the vectorscope as I go lower and lower and lower and it starts with 100 as you can see my bounding box is getting it crazy so I'm going to put a crop note here make sure you select the glow so the crop effects this resolution you have here and then I'm going to put it on top now the thing that I'm going to do though is I'm going to control the brightness of my inner glow so I'm going to brighten it down as much as I can I'm actually going to put a size of 200 and and then start bringing it up again so I'm just going to have like a really subtle glow I might just use the tolerance just a little bit I might do a really huge blur so I'm doing a 300 of blur and then a zero - of rightness and that should give me actually I'm going to lower even more so I'm going to put 0-5 so you see as you can see here I have really this really nice outer glow almost like the spilling like the lens is actually making a spill of light because the exposure is really hard for you to pick pick up and that's also giving me this really nice light-up effect on top of the fire so that's my outer glow now be careful with the outer glow it gets really saturated because as you brightness and do the tolerance it kind of gets a bit red so you might want to go into the saturation just lower it a little bit one of the things that I've noticed is that fire for it to look realistic on film usually you want to remove the saturation a little bit so I'm going to remove like 40 percent of the saturation I think that will give you a better glow effect so that's the as you can see that's already giving me a much nicer glow than what I had this looks like a some kind of shitty After Effects comp go that you can see from like a sapphire plug-in or something and this is like a really nice photographic glow of like a spread of light so now let's look at the other thing so now I'm going to do an inner glow so I'm going to just select all of this here and I'm going to paste it I'm going to connect it to this thing and now I'm going to really radical change this glow so I'm actually going to go ahead and set all of it to default because I don't want to really start out I want to start over I'm going to put an effect only as well on it and now I'm going to really crunch the tolerance I want to really only glow be high light so I'm going to lower the blurring for maybe five or six pixels and I'm going to brightness really low saturate quite a lot and then merge that on top so now this glow the inner glow is giving me just a little hint of light inside the glow so I'm just going to look at the result and see how much it's giving it so as you can see here it's just giving you just enough I'm gonna I am gonna blur it less because it looks a bit wrong I'm just going to blur by two pixels and of course the the amount of blurriness that you're putting on the inner glow has to do with the amount of pixels you're dealing with this is an HD image so one pixel is probably gonna be fine if using a 4k image you probably want to put more pixels on a blur depends on the image and so as you can see here this is just just giving you remember how dull it looks inside of the the fire this is just giving you a little slight overexposure on the fire inside of it and of course then the the this is all controlled by the tolerance so you probably want to improve the tolerance you probably want to improve the brightness to make it more overexposed and this is of course it's a case-to-case base like it really depends and on what you're trying to do for me because I don't have anything else I don't have any background I haven't don't have any other things around it I think this is looking okay for a fire that just like on these pictures would over expose on the inner core and not on the outer core now the other thing I'm going to also do here is I'm going to start doing a bit of color correction to this as well so at the very end I'm going to just put a color corrector node here and I'm going to tweak this fire a little bit so first of all I want to bring back some of the inner glow so I'm going to go into my mid-tones and just see if I can just bring in some gain and some gamma to the inner glow I'm also going to perhaps contrast a little bit remove some of the saturation as well of course now I'm just doing certain things that I think that look good but it doesn't really mean that you have to do that you know it's it's it's all about the tasting not only the taste but it's all about what you effectively you're comping to so it depends on the scene that you're doing but I think I'm quite happy with this you see we started with that fire and this is our result so the fire looked like that it was quite gold there was no sense of spread on the fire and now it has a inner core that is much more overexposed and it has an outer core the only thing I'm still going to do I think I'm exaggerating a little bit on this color correction just going to not have it so powerful I'm just going to lower some of these things that I've done here and just because I think I went overboard I'm also going to put my inner glow a little stronger so we see it a bit better my outer glow as well and that's really it now one last thing that sometimes I do and I'm just going to just going to play back this see how it actually looks and I think a little bit because it's a piece of red footage so just bear with me okay and as you can see here we're getting a really nice result we have a nice inner glow also you can kind of see that it's travelling a bit on the camera here you have the glow kind of moving a bit and that's all ten linked from the outer glow and it's tolerance and so this is a much more realistic fire now we can even improve this even better by of course putting a bit of grain if you have the grain from the plate even better if you don't have the grain from the plate you can of course invent some grain and I'm just going to put some grain just to show you how much better it gets it so as soon as you start putting grain of course I would have to denoise the plate to the fire first and then grain back this because what you want basically to actually properly do this might as well I'm here might as well do it properly so I'm going to do that I'm going to go in here to my red footage I'm going to pick up the red footage I'm actually I tend to use the denoiser called reduce noise and which is my terrifical again to denoise this kind of this kind of plate and it's really the best noise are out there for new clearly I think as if you guys want to check it out you should it's really good I'm just going to like do an auto profile of course this tutorial is not about the the noise of the fire so I'm going to spend too much time on this I just want to show you the noising really quickly as you can see we got rid of most of the noise now this is why I really like this divisor from neat video it's because you see all the details of the fire is still here and you only lost really what you don't want which is the actual noise so it's really powerful it's really really powerful stuff and so that's the noise now and then of course at the end you either would have to bring in the original noise or you would have to put some new noise whatever noise you would have if you have a grain plate or if you have a specific stylistic noise that you want to put in in here on my case I'm just going to do a stylistic noise because I'm not doing an actual comp so I'm going to just use a little picture grain and as you can see here now I have the correct grain on the actual inner glow in outer glow of the whole thing and so if you look at how this piece of footage looks like you know versus so this is how it used to look and that's the final result so you see you get this really nice light up on the middle and the actual spread of the fire the outer spread as well now if you wanted to push this even further sometimes depends on of course the project but sometimes I do even a third stage fire and and this is done either by using a glow this is going to be a really like like basically and like almost like a glint so imagine like lint glow and on this kind of situation what you want to do is you want to push the tolerance to almost the maximum so you almost have no tolerance and the brightness you probably can't push that much and then you also want to blur a little bit and that will be kind of fire now what you also have to do is I need to push the tolerance even more and I want to dispatcher eight even more so one you want what you're trying to get is these like pockets of glow they just show up if I played this back you'll see what I mean I'm just going to really quickly disable the reduce noise because the redoing reduce light is so slow so what you see here is you just basically trying to make this kind of blob looking fire I'm just going to bring it to maybe this much and I maybe not blur it so much and so you get this kind of inner glow and now once you put it in you see you just get these kind of highlights I'm just going to like not blur it so much and the other thing is well that I usually tend to do is I put a cheeky sharpen note here just so that I can get as much sharpness as that as I can from this I am also going to clip to clamp this clamp this put a sharpen and just put it on top what you're trying to do is to get these kind of inner light glows that just fill up these little pockets of fire and and it just gives you a little nice detail and then sometimes I even do a fir thing which is a glint you know and again this is just really a stylistic thing you might not want to put a glint on everything because it looks really horrible if you do to do that so I'm just going to really quickly not going to put a glow here what I'm going to put is a glint so the glint the way you're going to do it is the same way you're going to do effect only I am going to make quite long stripes I'm going to make like a bunch of rays I might even do 20 rays I just want to have a lot of sparkle on that and at least try first link that has to be much smaller almost like that and I'm also going to do the steps on a much more higher quality and and the link has to be much shorter and then what you have to do as well you have to like use the tolerance I'm going to actually make it on as much lower the fire much lower I'm then going to actually put a color corrector here it's saturated quite a lot glow it quite a lot less and then put it on top of the fire so what you want to do here as well as you want to put a defocus just so that it the glint and it it gets a bit more you don't want to have these kind of sharp and Spike's so now you also have to like use the tolerance even further and I might just make much more glow here yeah that sounds good to me I'm also going to make the D focusing a bit less and that should give me just this extra kind of glint that happens on top and so now let's have a look at this let's play it back and see how it looks especially if I use from the beginning so I'm going to do that I'm going to just do from the beginning or it looks so that you can kind of see it growing off-screen almost and that could be quite cool and now we wait for it to actually record ok ok sorry I put the beginning of the clip of course now we see the guy actually lighting up the fire blossom there's another matter what I really want to show you as you can see now we have a really nice outer glow that kind of fluctuates with the image we have a really nice inner glow that with the over exposes in certain moments and as you can also notice there's like these really nice little details of little like little pockets of little small little glows which are coming from that glint effect that we're trying to produce so as you can see this is looking at much like a much more photographic kind of fire and because of the outer glow we even can kind of see that really nice displacement going on on the floor and everything so just to recap as you as I showed you we start with a really nice outer glow which is a bit too saturated and merged on top we then have an inner glow which is really not not blurred to saturated a little bit with a lot of tolerance on the glow then we have a little very very small tolerance glint glow and then we have a bit of a glimpse as well with a lot of the focus in color correction all of it together with of course denoising the plate first and then of course regaining the plate with the correct grain in case you have light of course and that's pretty much the tutorial for today as you can see we get a pretty good photographic fire with the whole thing this process works really well with CG fire so maybe next time I can show you actually how that works and so that is it for me today so as always please don't forget to subscribe you gos desk that will really be really cool if you do that also please share with your friends if you think someone that you like the likes visual effects might want to check out my channel as well also of course please feel free and help me and pledge around the more money I can get in patreon the the more tutorials I can produce and I my hope is that someday I can have enough money in patreon that I can produce like weekly videos for you guys and of course follow me on Twitter you will see Guetta I hope you enjoy the content and thank you so much for your support I'll see you next time on more you guys desk hope you've enjoyed this video I'll see you around thank you [Music]

Channel: Hugo's Desk

Views: 38,329

Rating: 4.9203792 out of 5

Keywords: Gaming, Tutorial, Training, Compositing, Nuke, Hugo Guerra, After Effects, The Foundry, 3D, 2D, CGI, CG, Matte Painting, Hugo's Desk, MPC, Framestore, The Mill, 4K

Id: HoSv0pHQ_vg

Length: 22min 56sec (1376 seconds)

Published: Tue Aug 08 2017

Reddit Comments

[u/artsyfartsy-fosho]

I also love Hugo's tutorials. And he does them so professionally. His setup is hardcore lol.

And he accepted my LinkedIn invite, so I guess you can say it's getting pretty serious.

[u/statusquowarrior]

As a total begginner, I love Hugo's Tutorials.

His deconstructions teach you pretty much everything about high level compositing, without getting bogged down on the technical aspects of roto, keying etc.

[u/karlo_m]

RemindMe! 18 hours