How to Use Mocha for Tracking and Clean up After Effects - Tips from a Professional VFX Artist

well hello there I'm Marc Christiansen visual effects artist and motion designer in this short video I'm going to show you a mocha tracking tip that will basically give you a new superpower [Music] motion-tracking is one of the most common tasks and After Effects artists will tackle I'm going to show you a time-saving trick that will blow your mind now if you really want to hone your compositing chops check out the effects promotion the compositing and visual effects class that's built for motion designers you can also download the project files I'm using in this video to follow along or practice with after you're done watching details are in the description alright so here's a fun challenge we're going to remove the word stop from the stop sign most likely illegal we're going to replace it with the school of motion logo now on the surface this may seem like a fairly straightforward tracking exercise but if you approach it the wrong way you'll be fighting the software the entire time the first thing we're going to need to do is track the sign we're going to do that using mocha AE which comes for free with After Effects so that applied the mocha AE affect the layer now I'm going to click this button but before I do that I need to be in full resolution now a mocha has open and we're ready to track even though this is sort of the light version of mocha it is very powerful and there are a lot of features if you really want to go deep with this tool check out VFX from motion linked in the description mocha is a planar tracker which means that it can actually look at a very large area of your image and figure out how that area is moving it can even pick up things like perspective change which is present the beginning of the shot right here so to start I'm going to come up here and just grab the X spline tool I'm going to zoom into the image a little bit and then I'm going to draw a shape around the word to stop all I'm trying to do is pick an area that has some good details so that the planar tracker can keep track of it now because this tracking area is moving rotating scaling and shifting perspective we do need to have all these boxes checked down here now I can track forward you can see that mocha is doing a very good job of tracking this blue area tells me that this part of the shots been tracked and now we need to track backwards from this frame this error message is just telling me that at this frame there's not left to track as we scrub through this you can see that Moka did a really good job of tracking even at the beginning of the shot now typically what you would do at this point is name the lei or something like stop sign then activate the surface four layer this blue box has appeared and what we can do is position it relatively in perspective as best we can this is the area that will get corner pinned in after-effects we can even insert a clip here like a 16 by 16 grid to check how well this track worked and you can see it's a good track now all I have to do is save this and head back to after-effects here is a comp that's 1920 by 1080 with our logo scaled up to basically fill the frame the reason I chose this size is because that's the resolution of the shot that we tracked so in the corner pin data that's coming over from mocha that's going to be based on that image size if I drag it VAT comp into the comp with my sine footage I can then even apply the tracking data from mocha what I need to do is twirl down tracking data and go and first create that tracking data in the effect there's only one layer in there and it's turned on if I turn off the logo layer you can see that now the corner pin information has been applied now I just need to apply that same corner pin to my logo if I go back to this mocha effect now I can set my export option to corner pin supports motion blur so that I actually get motion blur for free from After Effects then I make sure I'm exporting to the correct layer and hit apply now the logo is stuck to the sign it's tracking really nicely but you're probably noticing that it's not the right shape it's been squashed a little bit vertically this is really one of the challenges of using this workflow with mocha you can see that the corner pin is based on the surface that I set inside of mocha which was not sixteen by nine however the kampala my logo in it is sixteen by nine on top of that I still need to remove the word stop it's going to be extremely difficult to create a patch for this when I have to figure out what that patch should look like in a 1920 by 1080 comp that's going to get squashed down to this size here but of course there's a better way which I'm about to show you the first step is to pick a good frame to use as the storage for cleaning this up so in this case what that means is I don't want any motion blur and I don't want to pick a frame where the stop sign is really really small in the frame if we're zooming in or something like that in this case I don't have that issue so I can pretty much pick any of these frames this one here is nice and sharp and I'm going to put a marker here with the asterisk key while I'm on this frame I can go back into mocha I'm in sync with after-effects right on that frame what I'm going to do now is first remove this inserted clip I'm going to select this layer and then I'm going to click this button over here what I do you might notice that the surface has been expanded to fill the frame if I scrub through you'll see that it is still tracked to the stop sign now why is this useful you'll find out in a minute the next thing I want to do is duplicate this layer I can remove the mocha AE effect now I want to freeze-frame this layer right on this frame so I'll right-click time freeze frame then I'm going to pre compose the layer I'll move all the attributes into this new composition and name this patch next I'll come into my stop sign layer and I'll recreate the tracking data using that stop sign layer I'll set the layer export to patch and apply the export now it might not be entirely obvious what's happening yet but basically the patch layer which again is just one frame this video is now being corner pinned and distorted to perfectly match the motion of the stop sign let's go into the patch pre-comp and confirm that this is indeed just a still frame to give you a better idea of what exactly is going on I can do a couple of things first of all I can put a mask on this layer like this then just for demonstration purposes I'm going to apply a hue and saturation effect to this and invert the hue back in our main comp you can now see what's going on anything that I do in this patch layer will now come through on the footage pretty slick and because we exported using the corner pin supports motion blur option I can click the motion blur button what that does is give me free motion blur at the beginning of the shot so we've got two tasks here the first task is to paint out the word stop creating a blank stop sign that's going to be a little tricky because of the texture on this the second task which will be far easier is to composite the school of motion logo in place on the sign now I could use the clone stamp tool to do this all in After Effects but I'm going to do it a different way the way I prefer to do this is in Photoshop so I'm going to export a PNG of a single frame I'm using video co-pilots console plugin which makes this really really easy I can just copy this frame to the clipboard instead of Photoshop now I can do make a new 1920 by 1080 frame and paste my shot right into it now I just make a quick selection of Photoshop then I can go to edit content aware fill then using this tool which works really well in Photoshop I could clean this up this whole process took only a few minutes and once it was done I use the clone stamp to add a few more details and then it was good just like that it's done I can now save this and re-import it into After Effects so I've imported that file and I can just drop it on top like this then I can lower the opacity just a little bit like this that I could see where the stop letters are and draw a simple mask around them now turn the opacity back up and feather the mask a few pixels now we've got our patch I can now set this original layer here to be a guide layer so that it won't show up in the main column now we have a clean stop sign the next step is pretty easy I can just drag the school of motion logo right on to this comp and then scale it down and position it where I need it for this because the shot is in perspective it might actually be easiest to use the corner pin effect now the perspective looks right on it but it's missing some of the texture that was showing through on the stop sign letters in fact if we turn these layers off and look at the stop sign letters they're not truly white so I'm also going to apply a fill effect to the school of motion logo I'll color pick the main white color of the stop sign I'm going to try and find the brightest part which is probably right about there then I also want to try to get some of that gritty stuff to show through so here's what I'm going to do I'm going to duplicate my patch layer and move it above the school of motion logo then I'm gonna duplicate the logo and move it above and set my patch to use that as an alpha mat let me rename these so it's clear what they are then I'm going to use a hue and saturation effect to remove all the color from this then a levels effects that I can get more contrast out of the image then I can set this to multiply mode so that it shows up over the logo next I can adjust the levels even further and play with the opacity until I'm happy with it this logo is also very sharp compared to the rest of the image if you look at the edge of the stop sign here you can see that the edges are definitely not very sharp because this is a prosumer camera so I need to mimic that the quickest way is just to add fast box blur to pixels seems to work pretty well so now the logo is comped onto the sign it's even got some of that grunge and dirt showing through and voila we have successfully tracked in a pretty photo realistic way the school of motion logo onto a stop sign now to really sell this composite there was a little bit of extra work I had to do I had to keyframe a levels effect because the darkness of the stop sign changed a little bit as the camera panned toward it I asked her to adjust the saturation so I use the tint effect to do that then I added noise to match the digital noise from the camera these are all the things we talked about in visual effects promotion and they're all very helpful in selling a composite pretty cool huh now you know one of my favorite mocha power moves this trick has saved me so much time make sure to hit subscribe if you want more tips like this one and check the description so that you can download the project files from this video if you want to really learn the ins announcement compositing including tracking match moving roto more all with the help of experienced industry pros and fun real-world challenges check out our class VFX promotion thanks for watching [Music]

Channel: School of Motion

Views: 74,085

Keywords: Motion Design, Motion Graphics, After Effects, Tutorial, Tips, Tricks, Technique, Learn, Basics, Design, MoGraph, VFX, Motion Tracking, Compositing

Id: C_dO9HGrYS8

Length: 11min 3sec (663 seconds)

Published: Mon Mar 09 2020

Reddit Comments

[u/dannydirtbag]

Motion tracking with Mocha is really great, except I have to re-learn it every year whenever I need to use it again. It never seems to stick - but this tut looks promising!