Simple Sky Replacement in Fusion

in this video you're going to learn how to do a simple Sky replacement in the fusion page of DaVinci Resolve here's what we're making so here's before and after so we have just a little bit more interesting Sky being put in there this is a really simple technique to spice up your footage with an otherwise kind of boring Sky my name is Casey I help content creators make amazing things in Fusion I also have a free video course the fusion Survival Guide available in the description below more on that later let's jump in shall we so there are a couple things that we need to do to make this work one is this shot is moving a little bit we have just a little bit of camera movement so we're going to have to track the motion and we're also going to have to key the real sky and put the fake sky in so I have my original footage laid out here in the timeline and I'll just go down to the fusion page button and click on that and that will open it up in Fusion one thing I'm definitely going to need is a fake sky so I'll go up to my media pool and here's where you can import a still or a video I have a video of this just kind of Cloudy sky here which is a lot more interesting than our just pure blue sky and I'll grab this and drag that down into our node graph and that makes a media end node and I'll just hit F2 to rename that and we'll call this sky and our original footage I'll just call OG for original footage I can close my media pool and now we have the two main ingredients we need first thing I'll do is take our sky and we're going to merge this over our footage I can do that by making a merge node and I can quickly make a merge node by dragging the output from this node onto the output of my OG my original footage and things seem to be in order now I need to put this original footage which I'll just bring up in our first viewer here by hitting one on the keyboard I want to put our original footage over it and I want to get rid of this blue sky just by keying it out just like you would with a blue screen or a green screen so how do we do that well with nodes we can actually put this footage in multiple different places in our kind of stack of elements here and so I could do something like grab a merge node and just drag this in so that it's in between my sky and my media out and I can take the output of my original footage and put that into the foreground that's the green input of our merge 2. and now it's going to be a little bit confusing but if I move this around we can see that this original footage is going into my merge 1 where the sky is being put over it and it's also being piped into merge 2 and it's being put over the sky so what we've essentially done is sandwiched our sky in between two copies of the original footage okay I can organize this a little bit by holding alt and grabbing this line and I can kind of make a little elbow like this and then I can just kind of organize this flow a little bit I like to build my main stack of elements just kind of from left to right and if I hit one for each of these I have our original footage and then we have our sky on top of that and then we have our original footage on top of that again okay so now let's get rid of this blue sky in our original footage so that we can see the fake sky below it we can do that with an effect called Delta here this is the main way to do kind of blue screen green screen keying and to quickly add a node I can just click here in the empty space and then hit shift spacebar that'll bring up my select tool palette and then I I can search for whatever I want so if I type key that'll bring up all the different keyers that we have and what I want is the Delta here this is just kind of the main keyer I can also hit DK for a shortcut and then I'll hit add that'll add a Delta keyer to our nodes here and there are a few different inputs the main one we're going to talk about is the yellow input this is kind of the main footage that we're going to keep okay so I can take the output from our original footage which is just going through these elbows here and I can put that into the Delta keyer and actually I'll get rid of this connection here and take the output from the Delta here that's the little gray square and plug that into the green input for our merge so now all we're doing is merging our footage over the sky and we are running it through a keyer but we're not keying it yet so let's go ahead and key it I'll just grab this eyedropper and drag it over the sky like this and we'll just kind of move this around until it feels like we have a pretty good key and that looks pretty good now from afar as we're zoomed out we'll say hey we're done right but there's a couple problems one of them is if we zoom in here a little bit we'll notice a couple things one is that the edges here there's kind of this little line around him and it just doesn't look very good the other one is that down here we can actually see some sky in this Shadow because the shadow is sort of a similar color to our original sky and so if I were to do something like select this merge that our sky is plugged into and turn the merge on and off that's going to basically turn off that layer we can see that it's affecting these Shadows right here so that's not something that we want so one thing that we can do is just mask our sky so that it doesn't go down in the shadows that'll also help with blending it with these trees a little bit it'll fix a lot of problems actually so how do we mask something well it's nice to mask something on the merge because the merge has one job the merge's job is to put something over something else this one is putting the sky over our original footage okay so we're going to tell it to only do that inside of a mask our masks are up here kind of under our transport controls there are a bunch of different masks you can use I'm going to use the polygon mask that's the third one over and just drag this down here and I'll take the output of the polygon mask and plug that into the blue input of this merge okay now I can draw a shape and we'll just kind of do something like this and I'll make it big and wide at the top like that and now that sky is only going to be merged over inside of that mask well this looks not great so far because we obviously have a mask here but we can soften the mask if we just select this polygon I can go over here to soft Edge and I can push that up and that's going to blend that together really nicely with our original footage actually so we could probably even select these points like this and just move them up a little bit so the more we move them up the more we'll see just the original footage okay maybe take this soft Edge down a little bit yeah something like that okay so now we have a little bit of a fade here which you could probably notice when you turn this off and on but there's a little bit of a fade but you're never actually going to notice that in real life it still looks pretty good and maybe a little over here take that down maybe soften this just a touch more okay so now when we turn this off and on we don't have this affecting our shadows at all right so that fixed one of the problems the other problem with this kind of stroke around our guy is because of our key so if we go to our Delta keyer we can go up here to where it says View mode and here where it says final result we can select matte and that's going to show us the map that it's using a matte is just a black and white image that controls the transparency of something so basically anything that's white is going to be totally opaque anything that's black is going to be totally transparent and gray is in between so right now the way this is keying we're going to see some of the sky behind our guy and also in the bike and a bunch of other places anywhere where it's gray we're going to see a little bit of Sky through him y'all people don't believe me if we go back to final result and I grab my sky merge again and I turn this off and on you can see that it lightens and darkens his shirt that means that we are blending the sky in and it's lightning things it's like way too soft on the bike there's all kinds of problems with this mat so what we want to do is make sure that our mat is really nice so we can select Delta here go back to our mat here and there are a lot of controls for the Delta gear the one you really need need to know about is under this third icon here under mat there's this threshold and you can fix a lot of stuff just with the threshold okay so what we want to do is make him Pure White and the background pure black so I can push this low threshold down that's going to make more things black so I want to push that up just a little and I want to take the high threshold down as I pull that to the left he becomes more white and we got to kind of decide how much we care we want most of him to be Pure White this is technically a problem right here where it's showing the sky it's probably not something anybody's going to notice or care about so we're going to kind of just say it's good enough for government work and here where it says Matt let's go back to final result and now when we turn off and on our Sky merge here we zoom in we don't have that big difference when we turn that Sky off and on okay it's a pretty good key now there's also still the problem of these edges one thing that we can do that's pretty easy is Select this Delta keyer and there's this control under mat which is erode and dilate what this does is it shrinks down that matte so that we don't have those edges now you want to be really careful with this but because it will get rid of details and make things look like terrible but if you're really gentle with it you can just push that in just a little bit and that will clean up your edges quite a bit okay so now we have our sky and we're getting a little bit better result here now there are still some problems with the spokes and so we're gonna have to kind of decide how much we care about that we can adjust the threshold a little bit and push that down and get a little bit more of those Spokes and we can kind of play around with that but it's always going to be balanced between your main edges and your little details like this so the question is what's the most important to you what's the most dead giveaway and I think you know zoomed in here yes it's not super amazing but since we're only going to be looking at this zoomed out for the most part it's probably fine also because he's moving around all the time you're not going to notice that some of those spokes are not really there okay so that's a pretty good start the other thing with this Delta here is that it tends to add a bunch of noise to your clip and there are ways to get around it and mess with the settings and everything but honestly the very best thing to do is instead of using this Delta keyer like this we're going to use a new node called map control if we hit shift spacebar m-a-t-t-e we're gonna bring that up and we're going to use this map control to basically do the same key but without the noise that the keyer adds to it okay so we're going to go ahead and disconnect the Delta keyer now that we have it pretty much locked in we're going to take our original footage put that into the Mac control and we're going to take our Delta here and plug that into the green input of the Mac control okay so original footage goes into yellow that's the background and our key goes into the foreground what this Mac control is doing is taking this mat that we are making with the Delta gear this black and white image and it's cutting out our original footage with the black and white image in a way that's just a little bit cleaner than the Delta keyer okay to get it to do that all we have to do is Select this matte control up here where it says matte combine let's just say combine Alpha and then go down here to where it says post multiply image let's click that so now we plug this into our merge and we go back to final result here we have a very nice clean mat where are using the transparency in this Delta keyer as a mat to cut out our original footage and we get a much much cleaner result this way here we can kind of preview this before and after by clicking on and off the Mac control and there's still a few little problems again one thing with visual effects is you do what you can get away with these edges probably wouldn't pass for you know a super professional blue screen or green screen but it's probably going to work just fine for what we're doing so now we're almost done we have the guy jumping looks good the sky's behind him but we have this problem here where the camera moves and the sky doesn't which is a dead giveaway that we replace the sky so what do we do about that well anytime that you want something to move with a moving camera you have to track it and kind of apply that tracked motion to whatever you want to stick to the shot so we can go back to our original footage here let's just click here in the blank space and hit shift spacebar and we'll type plann that'll bring up our planar tracker the planer tracker is a quick way to track a bunch of points and kind of average out their movement which is great for things like this like a sky replacement we're going to take the output of our original footage plug that into the yellow input of planar tracker and I'll bring this up in our first viewer by hitting one on the keyboard and now we see our original footage before we've done anything to it and I think what we want to do is just select probably this stuff back here we're looking to just draw a shape around elements that are high contrast so that it knows what we want to match the motion of so we'll just do kind of a big section like this and over here under the inspector controls for the planar tracker we want to change a couple things first thing I'm going to do is set our reference time that's basically the time where we selected this shape under tracker we can leave his point under motion type instead of perspective I think we'll just do translation rotation and scale basically at the top of this list is the simplest way to track and the bottom is the most intense way to track you generally want to pick as far up the list as you can if something's just moving up and down left and right that's translation if something's moving all directions and also rotating we might do that if you're also zooming while that is happening we can do translation rotation and scale so I think that's what I'll do because I feel like there's a little Zoom to this and everything else is good we're at our reference time at 45 frames and I'll just click this track to start button to track it backwards and now I can hit go to go back to our original frame and then track forward track to end like this so now we've tracked the motion of our shot like this and we can take this motion and we can apply it to anything we want by clicking this create planar transform button what that'll do when we click this is it's going to make a new node and this is a transform node and so anything that we run through this node is going to move in the same way that this part of the image is moving which is perfect if we want our Sky to move that way so I'll take this Sky I'll take this planar transform and hold shift and drag that in between the sky and the merge like this so when we grab it and wiggle it it should wiggle around like that and now let's see what we got if we play this back oh dang baby the sky is moving along with our shot it's not a dead giveaway anymore it's looking pretty good but there is a problem we have the this edge here so what we actually want to do is scale up the sky a little bit before we apply that motion so we can just take the sky and I'll just hit shift spacebar and type XF that's a quick way to add a transform you can also just drag it in here from the toolbar let's grab this transform and we'll just scale this up a little bit so we'll just say size and we'll just scale that up nobody's going to know that we scaled it up and if it stays on screen the whole time that's really all we need to do looks good to me and now that I'm done tracking I can get rid of this planar tracker because all of that tracking information is right here in the planar transform okay so now our original footage goes into the Delta key here and the matte control the matte control uses the key from the Delta keyer to cut out the parts that we want in our footage basically just keeping these parts right here then we're putting that over our Sky which is merged over our original footage we have this original footage in the background so that anything that we aren't covering with our key and anything that our Sky doesn't cover just looks natural it's just the original footage right so we go original footage sky and then our keyed footage on top of that and there we go there's our replaced Sky not too bad right if you want to learn more about working infusion I have a free course the fusion Survival Guide make sure to check that out it'll teach you my top tips for working in Fusion effectively and efficiently and all of those other adverb words that are really good I hope you had a good time what do you want to learn to do in Fusion put your requests in the comments below and maybe I'll make a video on it you never know you just you never know

Channel: Casey Faris

Views: 5,902

Keywords: Davinci Resolve 17, blackmagic design, casey faris, how to, free video editor, tutorial, davinci resolve 18, resolve for beginners, davinci tutorials, editing, fusion, davinci resolve 18 tutorial, davinci resolve 18 tutorial for beginners, davinci resolve, Simple Sky Replacement in Fusion, davinci resolve fusion tutorial, davinci resolve fusion effects, davinci resolve fusion, davinci resolve fusion mask, how to replace sky in davinci resolve, how to replace sky in fusion

Id: ojag53rOrBE

Length: 14min 25sec (865 seconds)

Published: Wed Jun 07 2023