How to use RotoBrush tool in After Effects ➡ Then import the data in Blender 3D: VFX Tutorial!

what's up guys it's Brad from light architect in this video I'm going to show how you can use the rotor brush and refine map tool instead of after effects and then export and utilize that precise matte data instead of the blender compositor [Music] most of you guys already know what rotor scoping is but for those of you who don't know rotoscoping is the process of cutting out an element from your live-action shot so that you can then occlude it over top of your background that you're adding to your scene so for example in my case if you don't have a green screen behind your actor in your live-action shot and you want to add this full CG environment in the Deep background we're going to actually have to cut out frame by frame using rotoscoping around our character here so that we can actually put the CG environment into the deep background so I'm going to be using this composite I've created here inside of blender a while ago as an example for this tutorial but of course this tutorial applies in many different areas this is our compositing node tree inside a blender but have no fear because the rotoscoping part of this tutorial is just going to be these guys right here so it's going to be a very simple tutorial on how we can create that matte inside of After Effects and then utilize that data inside of blender so I'll go ahead and show you guys a before and after here of what this rotoscoping data is going to do so I'll go ahead and take it away here are our character we have our live-action character here that's supposed to be in the foreground of our shot from our video so for example if I go here and I'll just connect our video here this is our live action shot and we've added that CG environment to this shot but as you can see our CG environment is actually being overlaid on top of our character as well which is why we need to rotoscope our character out frame by frame now we could do this rotoscoping process inside a blender however I found that when it comes to detailed rotoscoping it's better to use a more advanced tool such as the rotor brush to get these fine edges like this hair here so obviously you could go into the masking tab here and you could create a new mask and you know command click and roughly go around your character here for the sake of this example I'm just going to do a really rough mask and you can obviously be really precise with this but it's going to be very tedious to get those hairs anyway but of course you can do this and then you know you can insert keys and animate this mask over time and then once you've done that you can label it here and then and of course you can use that data using the input mask option and you can find and utilize this Mass data effectively just like we're going to show how to use the rotor brush tool in this video but anyways I digress let's get started instead of after effects alright guys here we are inside of After Effects this is a new project that we have created here the first thing we're going to need to do is import the image sequence of our live action plate so I'll go ahead and just go to file import file and then I just have our image sequence here of our live action shot and since we're using an image sequence we want to select the PNG sequence option here and then click on open and now after effects is going to open up that image sequence and one thing we want to do is make sure our frame rates match from after effects to blender I know this particular shot is shot at 24 frames per second so I'm going to change the frame rate from 30 to 24 really quick just so we have a very clean and precise workflow here so I'll go ahead and just right click this interpret Main and then I'll just change our assume frame rate to 24. go ahead and click OK and then I'll just grab this image goes here and create a new composition and just for the sake of this tutorial I'm not going to rotoscope out the entire sequence with the Roto brush tool here I'm just going to do maybe one second but obviously you should rotoscope the part of the clip that you actually need for your composite so I'll just do one second here for the sake of our example and I will trim our composition here for now for the sake of our example and to use the rotor brush tool all you have to do is navigate up to the icon here and click on it and now we'll double click on our footage and this window will pop up where you can see your rotor brush icon here now it's pretty simple to use all you have to do is just drag over the portion of the area where you want to Roto out and it's going to sort of just guess the edges at first so we're just going to kind of drag around here and you can see that we're getting a little bit of the railing here so in order to make sure that's excluded from the rotor data we can press option or alt if you're on Windows just drag this here and you see that we're getting a nice mat now going back to the hair here this is one of the reasons why I like to use this tool because we have a refine an edge tool so it'd be really tricky to manually cut out these hairs but that's why this refined Edge tool comes in handy so once you get the general shape of your rotoscoping data so you know the part of the image that you want to cut out and overlay into your scene so I think this is looking pretty good again option and dragged to exclude something from an image and then just drag to add something and then also I should mention that if you press command and scroll you can change the size of your rotor brush which is very helpful anyways now that we have our general shape on this first frame we can refine this data and actually try to get some of these hairs in our matte data as well to do that we can click on our rotor brush icon here and then we'll click on the refine Edge tool and this one has very similar controls we can still press command and drag up and down to change the size of it but now as you can see here if I just drag over the edges of our mat like so and then release you can see that it's actually creating a mat for this fine detail of our character's hair here which is very helpful in that very fine detail so I'll just drag this all the way around to wherever those hairs are of our character and there's a little bit here as well and now we're going to have a much more precise Edge and we're just going to do this on the hair because the rest of our mat looks pretty clean here so now that we've done that we can switch over to our standard water brush tool and we can just press Command right arrow key to go one frame forward and we'll just keep doing this pressing command and right arrow key just double checking our Roto data now a lot of times if your character is moving a lot the rotor brush tool will not capture exactly what you're looking for and all you have to do in that case is either option and subtract a part that you want to exclude from the rotor data or you can add it back in with a brush stroke okay so say for example here we have some area that we don't want to add to our router data we can just exclude that on this Frame and after effects will use that to calculate the next frames as well and you can also go through several frames at a time here if your character is not moving too much so I'll click on command and arrow key five times and we'll just see how it's looking and see if the refine Edge as well as the rotor brush Works effectively here and it's still looking pretty good looks like we have a little bit of this uh metal railing in the background so I'll just kind of scale down our rotor brush tool then option and click there and now you can see that disappeared so pretty simple process you're just going frame by frame and the rotor brush does a lot for you that in blender or in just traditional masking techniques would take a lot of time so I'll go command five frames over with the arrow key and it's looking pretty good do that one more time now there are other rotor scoping tools out there but this just happens to be one of the most commonly used ones because after effects is a very common tool for Freelancers but it looks like we're getting a little bit of our background here so we'll just remove that add this back in so this is just going to be a much easier way to create matte data so you don't have to do everything frame by frame okay so now we've gotten to the end of our one second and our data is looking pretty good once you have gone through all of your frames here and your Roto brush is done propagating you then need to freeze your data so go ahead and click on freeze and after effects will go through all of your frames and freeze the mat and then we'll get into our rotor brush and refine edge settings over on the left panel here all right so after effects has frozen our mat now we can go back to our composition and you can see that our character is nicely cut out here with the checkered background displaying where our output channel is you can see that our hair is looking pretty clean here for an HD composition obviously there's a little bit of a blue edge but that's just from our environment now before we export this mat I recommend you go into your Roto brush settings here and play around with some things accordingly if your mat isn't looking super precise mine's looking pretty good so I don't think I'll have to change too much but you can play around with the Feathering of the mat as well as the contrast and a lot of the time if you have kind of rough edges reduce chatter helps a lot but just use a lot of these with caution as sometimes they can make it look a little too smooth so you can play around with these settings and you can also refine the fine detail with the refined Edge matte settings right here one thing that's also helpful if you're going to use this data inside of After Effects is the use motion blur option as well as the decontaminate edge colors as you can see here it helps with getting rid of that blue background that's affecting our hair so if you can gonna turn this off and on you'll notice that it's just decontaminating those Edge colors that are coming from the background now since I'm just going to be using the math data from this inside of blender this decontaminate Edge colors won't really matter that much but I'll just select it anyway just because it looks a bit nicer anyways this looks like a pretty clean mat to export this data as an image sequence and then use it inside of blender we'll just go to composition and then we'll click on add to render Cube and now our render queue will pop up here and we can go into our output module double check our settings one thing we want to do is switch our format to a PNG sequence so we can use it inside a blender with an alpha channel so go ahead and click on that and then we're also going to want to switch our video output from RGB to RGB plus Alpha you can use Alpha if you just want to use that map data like I'm about to do but I find that just having the option to use the RGB data is helpful as well so go ahead and select this and I'll click on OK and now you can choose your file output here so we'll just create a new folder here we'll call it woman Roto data create that folder and then we'll label our file called woman Roto data okay go ahead and click on Save and again I've already exported the sequence prior to this tutorial but all you have to do to export this data with our Alpha Channel now is click on render and then you can use this data in the blender compositor so go ahead and click on render and then we'll hop back in to blender all right guys we are inside a blender to start off we'll just delete our old rotor data here with the exception of our live action plate so we'll go ahead and select these and press X to delete and we'll also delete our Alpha over node right here and now as you can see here we just have our live action plate to work with and we're going to Overlay this live action plate on top of our composite here while using our exported matte data to tell blender to only overlay that specific portion of our plate so to start we'll import our matte data so go ahead and press shift a we'll go to input image and we'll open up our image here and this is our woman Roto data I'll grab all of these files so 280 frames that I've created are rotor data for exported from After Effects go ahead and open these up and now we have some Roto data to work with and you can see we have an alpha Channel which contains our math data and that's what we're going to use to define where to Overlay our plate on top of our composite so now that we have these two bits of data to work with I'll press shift a We'll add a color Alpha over then I'll drag this on top of our compositing node tree and then I'll just overlay our live action plate here for now and now we'll press shift a and I'll search for a set Alpha node add this between our live action plate and our Alpha over node and now as you can see here only our character is being overlaid on our live action plate and the reason we're not just overlaying the image from our voter data on top of our composite is because we actually might want to refine the mat a little bit more so we might want to add for example a dialect erode node to either pull the edges in of our character or maybe even increase them outward a bit so that's where we're not just overlaying the image data of our rotor sequence because we just have a little bit more control if we have the actual play data in this node setup so in this case I think we could erode a little bit of our edges to get a little bit of a cleaner composite so to do that I'll press shift a I'll search for dilate erode and we'll add this right before our set Alpha node and now we can either erode the edges here by creating a negative distance or we can actually feather the edges with this setting and we can you know maybe feather the edges by five for example five pixels just to kind of blend in the edges of our character to the live action shot a bit better now it's kind of hard to see which is five pixels but to give you an example I'll do 50 and that should be fairly prevalent so let's go ahead and check it out and now you can see these edges are feathered in quite a bit now obviously this isn't what we want we'll probably just keep this at zero but this is just one way you can clean up your mat if necessary and match the live action shot a bit better if your rotored elements for example has some blur on it where the edges aren't totally sharp anyways guys that is how you can use the Roto brush tool and refine Edge tool instead of after effects and then export that data into blender in order to use it effectively in your Composites I hope this video was helpful as always feel free to leave a comment if you have any questions or suggestions in the comment section below let us know what visual effects you'd like to learn next on the channel and I'll see you next time please [Music]

Channel: LightArchitect

Views: 3,567

Keywords: after effects roto brush and refine tutorial 2023, roto brush tutorial ae, blender to after effects, blender 3d tutorials, visual effects in blender 3d, live action vfx in blender 3d, how to learn visual effects, filmmaking in blender, easy tutorials, rotoscoping in blender, rotobrush in blender, ian hubert, lightarchitect, william landgren, cg geek, best cgi tutorials

Id: pfXmCH2hCpI

Length: 13min 10sec (790 seconds)

Published: Wed Jul 19 2023