Tracking Heads with GeoTracker for Blender Tutorial

hi everyone today we're going to do some head tracking in blender using Geo Tracker and face builder in order to bring a 3D object into a live action footage let's jump straight into the project what you see here is a Geo Tracker panel we already have this free stock video loaded in our clip input and in a moment we're going to show you how to quickly and convincingly add a CG helmet to the guy's head first off we'll need to track it using a fitting 3D model and the good news is that we can create it right inside of blender what we'll need to do is Snapshot a number of frames in Geo Tracker and then load them in face Builder that will create a head model based on those snapshots so let's first delete this Cube from the blender startup scene and then go to camera view by pressing 0 on the keyboard or this camera button here and now we'll use the playhead to scroll through the timeline and just snapshot the frames by clicking this hamburger button and then pressing take snapshot [Music] foreign button and click add images to import the pictures we've just saved ideally you should have the pictures of the head showing it from different angles this will help face Builder make a more precise model what we need to do now is go through all of these images and click align face for each of them which will place the mesh on top of the head in the video thus automatically estimating its position in 3D space and then we'll need to fine tune it by dragging these pins or create new ones if necessary to make the mesh fit with all the facial features and will also disable the lower neck because it won't be of much use for us today so let's just do these adjustments for each snapshot you can learn more about face Builder from our recorded streams on King Tools YouTube channel and there are also many other detailed tutorials out there by some really cool video artists it's worth making this 3D model just a bit smaller than the actual head especially the neck part because we're going to use it as a mask in a little while other than that it it looks like we have the exact copy of the guy's head in 3D now let's go to Geo Tracker and select the head we've just built here in the geometry input then go to pin mode type in the new focal length value here in the camera Tab and we happen to know that it's 45 millimeters and align our 3D model with the head in this shot we're gonna go back to face builder for a second and temporarily disable the upper neck for a more stable tracking now we can finally hit track forward if you see that at some point the mesh is off you can adjust it manually don't forget to hit refine after each adjustment sometimes deleting all keyframes between the two manual ones helps to achieve a more smooth motion when you see that it's getting too rough let's go to face Builder again and enable the upper neck and what we have here is the result of our tracking is a video driven 3D animation let's now click export here in the scene tab to create an empty that's going to contain all the rotation and translation data we're going to use it for syncing our 3D animation with the CG motorcycle helmet that we want to put on the guy's head so let's go ahead and import this 3D model from the project folder that you can download following the link in the description and we're going to parent this helmet to our empty so that they move and rotate together let's fix the helmet's position and rotation so that it sits nicely on the head and we can make this kind of adjustment anytime in the future now let's go ahead and check what it looks like in motion that's nice the helmet motion is pretty accurate and it took us really a few moments to get this very smooth 3D animation and now the most intriguing part which is applying materials to make our helmet look cool and real let's first go to preferences and here in the add-ons search for this material library and tick the checkbox next to it which will give you access to the free blender material Library it's going to save us a lot of time as we won't be making materials from scratch and that's a great add-on especially for those who've just started using blender so let's go to material properties and add a new material then over here in the material Library VX tab we'll select this metallic paint for the helmet outer shell we need first to select the layer we want to apply to and then hit apply to selected now if we go to the material preview we see that our helmet is all made of this metallic paint that we've selected so let's see how we can separate the shield to apply a different material to it if we're gonna go to edit mode left click on any of these vertices then press command L and that will select all the vertices that belong to the shield now we go back to the material Library select fake glass for example and press the apply to selected button again and now we have of the outer shell and the face shield made of different materials you can go to the shading Tab and try different options for your materials let's say our helmet is going to be black also while we're here in the shading tab let's create a holdout material for our head that's going to help us hide this neck Roll Part which is supposed to be hidden behind the guy's neck so let's go over here create a holdout node and connect it to material output like this as you see the reason why the head model has to be so precise and why we made the neck a bit thinner is because we use it for cutting off this part of the neck roll to make the head look as if it's actually inside of the helmet one of the key things that make a helmet like this look nice and real is Reflections on its surface we can get them here by adding an environment map so let's go to world and create an environment texture node connected to the background and load this image that you can again find in the project folder we need to fix the rotation of our environment picture so let's go to rendered viewport shading create a texture coordinate node and also a mapping node connect them all like this and set the Z rotation here to 178 degrees let's now make the background transparent by going to the film Tab and Ticking this checkbox over here it's going to remove the tiny silhouette around the neck and the head of our 3D model now let's do a bit of compositing to put everything together we're not going to go too much into details here because it's not the primary goal of this video you can find more info on compositing in blender in the dedicated blender tutorials so let's go over here and tick the use nodes checkbox create a movie clip node load our footage in here and connect this to Alpha over node then connect render layers to Alpha over and Alpha over to composite node and also create a viewer node to be able to see the result let's now render the current frame that looks nice already but let's try to blend it even more into the shot what we can do here is create a color correction node wire it like this so we can tweak our helmet separate from the background shot let's increase Master lift over here just a bit and then let's also add a blur node put it right after our color correction and set X and Y to 2. now we see that our shot is pretty grainy so we can add graininess to a helmet too to integrate our CG helmet even more into this live-action shot so let's create a texture note then here in texture properties press new and switch its type to noise let's rename it to grain then create a mix node and put it in between the blur node and the alpha over node now connect the texture node to the mix node and here in the mix node switch its mode to multiply put this value down a bit and choose grain here in the texture node let's now enable motion blur in render properties to smooth out our helmet as it moves and let's see it in motion great so this is how we make someone wear a CG motorcycle helmet in the live action shot using the combination of Geo Tracker and face builder for blender download the zip file with the entire project folder following the link in the description to this video try different models and textures see how you can use this technique in your own workflow thank you for watching don't forget to subscribe to our YouTube channel and hit the Bell to get notified about our new tutorials and streams Geo Tracker and face build of a blender are available for download right now on kintools.io [Music] foreign foreign

Channel: KeenTools

Views: 45,990

Keywords: KeenTools, GeoTracker, FaceTracker, Nuke, Foundry, Object tracking, Tracking, Camera, Blackmagic, Fusion, VFX, Visual Effects, 3D, cinema, movie, video production, compositing, matchmoving, blender, blender tracking, camera tracking, camera tracker, geometry tracking

Id: eG-XFn8Iqng

Length: 8min 42sec (522 seconds)

Published: Tue Aug 08 2023