Basics of Geometry Tracking – GeoTracker for Blender Tutorial

hi everyone and welcome to the basics of Geo Tracker for blender in this video we'll guide you through the installation process show you the tracking Basics and talk about the tools you can find in Geo Tracker to manipulate your scene and also give you a very basic example of how tracking data can be used for adding CG elements to your scene in blender a quick note before we start this add-on was designed specially for blender which is a 3D Creation Suite and so it's a perfect marriage of object tracking and the 3D World with all its 3D elements and effects within one platform another important thing is this add-on contains both Geo Tracker and face Builder if you already own face build of a blender we strongly recommend using the updater otherwise you'll need to delete your current version of the add-on relaunch blender and then download and install the newest version you can install the add-on either online or offline but in any case you'll need to go to our website and download the installation package first and if you want to do it offline download the core Library too you might need that option in case you work on a computer that has no internet access once the download is complete go to add-ons in blender preferences press install select the zip file you've just downloaded and hit install add-on you will see this checkbox that you need to tick in order to activate the add-on and also accept the license agreement then press install online if your computer is connected to the internet or installed from disk if it's not and in that case you'll need to load the core Library zip file here as well wait till the installation is complete close this window and press n to see the side panel where Geo Tracker permanently leaves inside blender now when we want to track an object in our video we click on Geo Tracker Tab and then press this create new geotracker button which opens this nice little menu with many useful settings we're going to talk about right now the one we need to look at first is inputs over here we have clip and that's our footage in which we will track our objects this can be an image sequence or movie file so we're going to hit this folder icon and load this sequence that you can find in the project folder following the download link in the description to this video and in that sequence we see a GMC pickup truck going towards us along this sort of snowy and icy Road that's the one we'll be tracking today using geometry which is right here below the clip basically a geometry is a 3D model of a similar shape to the Target object that we want to track right now we have a cube in here which is the cube from the blender startup scene and so Geo Tracker just picks it from there we're going to delete this Cube because we won't be using it anyway instead we'll load a custom 3D model of a truck the standard blender way so let go to file import choose the OBG format and load it then you can either click on the empty field here in geometry and select it from the list or use the object picker to select it right in the viewport next is camera which we use as our Viewpoint again this is the same camera from our blender scene so as you see Geo Tracker operates the objects that you have here in your blender scene and we'll actually delete this light so that it doesn't distract us before we move on to tracking we need to do one important thing and that is hit this analyze button and then press ok now when we use this option Geo Tracker actually does what it says it analyzes the clip and saves it as a pre-calc file containing the analysis data to your disk which will make tracking a lot faster than without it by default this file is going to be saved to your temporary folder on Mac or disk C on Windows but of course you can choose a different location for it once the analysis is complete you'll notice that the tracking tab is unfolded and the first thing we need to choose here is what we will actually track the one selected right now and always as you open Geo Tracker is geometry and that's because geotracker is most often used for tracking objects by means of geometry so let's go over here and press the pin mode button what will happen is we'll see our clip on the screen or its first frame to be exact and this green wireframe on top of it which is our geometry what we need to do first is set up the initial position of our 3D model the one we've prepared for today is not the full truck as you see there's only the front and no trunk but that will suffice for tracking this shot still the model has to be as precise as possible if the wireframe color is too bright or dim you can always go to appearance Tab and customize its look adjust opacity or even choose a different color for it okay so let's put our model where it should be simply drag the wireframe to Overlay it on top of the target object if we left click anywhere on the wireframe this will create a pin which is this tiny little dot that's going to turn red when it's deselected and these pins can help us accurately place our geometry we can create as many pins as we need their amount is not going to affect our tracking and if you want to remove a pin just right click on it to get a better idea of what's going on let's add more workspace and split our window into two in order to see what's happening in the 3D scene and we see that all this wireframe manipulation results in the actual change of our model position in 3D space now you may notice that hard as we try our geometry is still a bit off the problem may not be in the 3D model itself but the wrong camera settings being used the thing is we need to use the same focal length value as the camera on the set had you can unfold the camera Tab and change that value right here in Geo Tracker if you know it but if you don't you can use automatic focal length estimation by taking this checkbox and this will calculate the focal length value for you note that this works only for the current frame while you're pinning your model and you need to have at least four pins set on your wireframe to make it work and by the way we shouldn't worry about the weird kind of placement that our model has right now in the 3D World we'll deal with it very soon now that we've finished pinning you can press this button which is track forward and just wait till the tracking is complete as we get closer to the end of our clip our wireframe Slips Away a little we can fix this by adjusting its position manually in this final frame our tracking data is stored in these green keyframes over here created by Geo Tracker and this new adjusted position of our geometry is going to be saved in a new keyframe Whose color is going to be yellow on top of the green dotted line indicating that it's a manual keyframe now we've fixed our tracking data in the final frame but the keyframes just before it still contain the old data we can see our wireframe performing a slight jump if we move the playhead between these frames what we should do here is update the tracking data between the keyframes so let's place the playhead somewhere in between and press refine you can set as many manual keyframes as you need for achieving a good tracking result note that when you hit refine or tracking buttons this doesn't modify the manual keyframes but only changes the tracking data between those frames let's play it again as you see the movement of our 3D model is now smooth and accurate which means we have some good tracking results here and our geometry is now perfectly synced with the truck's Motion in the video if we look at our scene in 3D space we'll notice that our truck is sort of taking off from under the grid floor rather than driving on it this is because we were tracking geometry relevant to camera while the camera itself remains static and we were not tied to any specific point in 3D space so let's bring the track on the surface and make it a nice looking scene we can easily do that by telling Geo Tracker to move the whole scene using geometry as origin point so let's go to the scene Tab and here in transform press the position button and then in this pop over we hit geometry and select world origin as a preset position this moves the whole scene so that the truck isn't the world origin but apparently trucks don't drive with their front facing up so let's put it back on the wheels and to do that we'll rotate the scene 90 degrees around the X and press ok to apply changes if we press play now we'll see that our truck is moving parallel to the grid floor and if we go to camera view this will look like a normal 3D scene now let's give a little example of how we can actually utilize it we're going to add a CG element to this video and say this will be a police light bar on the roof of our truck let's go down here in the scene Tab and Export our animated geometry as an empty we're going to select geometry here and we'll use this linked option so that all further changes of our tracking data and the animation copied onto empty will be synced so as we hit export we get an empty that is animated exactly the same way as our 3D model and we can turn its visibility on and off now let's get a police light bar in here and we'll import it a slightly different way this time we'll hit append in the file menu and select the scene in which our light bar was created then inside that scene we open the object folder and select all the objects that relate to the light bar so like the parts that it's made of all parts of this light bar make a group and they're all parented to the light bar empty layer so we're going to put it on the roof and also drag this light bar Mt onto gtmt holding shift to parent them and so now when we press play they'll move together like one whole thing if we take a closer look at the roof though we'll notice an overlay we're not supposed to see the basement of these light bar mounts as they should be blocked from our view by the roof in this shot so what we can do is go to the shading Tab and first select material preview then press shift a to create a new material which is going to be hold out now let's connect holdout to material output and we can delete this node because we're not going to use it and as we do so we can see that this makes our truck model transparent and at the same time it masks out the basement of the light bar mounts good but another thing we need to do now is go here to render properties scroll down to the film Tab and make the world background transparent because otherwise we'd see a weird silhouette around the truck you might notice that our light bar already contains some materials if you can't see them you should probably switch to material preview up here these are the materials we prepared in advance let's take a quick look at them this one is for the blue light and this one is for red and also materials for Glass and Metal parts that was actually why we used the append option to import the light bar model because we wanted to load it along with the materials that it has inside alright now we're going to load the environment texture so that we have some nice Reflections on the light bar surface to make it look more natural the reason we won't be using the HDR blender has for us here in the render viewport shading is that it has a lot of greens which we don't have in our shot so let's switch this Shader type to world then press shift a start typing environment texture and wire it to the background node then load this mod Road HDR from the project folder foreign because if we go ahead and set this Frame to render now this will render our 3D scene without any movie sequence in it so let's go to compositing workspace we need first to tick this use nodes checkbox then create a movie clip node click on open and load our footage in here now let's create Alpha over and place it in between the movie clip node and composite node then wire this rendered layers node to Alpha over and also create a viewer node and connect Alpha over to that one too and by doing that we've simply merged our light bar with the background video in our render this is what it's going to look like now if we render it and now let's finally add a glow the simplest way to do it is create a glare node and put it in between render layers and Alpha because we want to add this glow effect only to the light bar let's select for glow here in the drop down list and then duplicate it and insert it in between these will be two different glow effects so let's select strikes in here and we're gonna go down here and adjust some of these values to make it look nice let's go ahead and render this Frame now and that looks good we can now render the whole sequence to see it in motion the rendering is finished and it looks very nice these were the basics of Geo track of a blender and a little example of how you can simply and quickly add CG elements with some cool 3D effects to your video 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 for blender is available for download right now on kintels.io [Music] foreign foreign foreign

Channel: KeenTools

Views: 72,060

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

Id: v7R246evN_U

Length: 13min 9sec (789 seconds)

Published: Tue Aug 08 2023