Sphere Tracking

this video sponsored by Squarespace the all-in-one platform to build a beautiful website oh look another CG matter tutorial maybes gonna teach us how to make some cool explosions um nah that's incorrect okay maybe we'll learn how to take some footage track it and then put an explosion and our scene so that um no again it's now what we're doing actually this tutorial just gonna be about teaching you how to handle your blue ball so unlike normal tracking sphere tracking is something you can do completely manually takes a lot of time a lot of keyframes we can really get some good result and in fact this is the technique I use back in my metaball video and the basic workflows you find some single colored ball market with two dots which we're gonna need for tracking film some footage of you fondling a track the location track the rotation overlay this over your footage key out the ball so your fingers are in the foreground and composite everything together more nicely and yeah that's what we're gonna be doing it is a time-consuming process but I'll show you some tricks to make it faster and then I'm gonna trickshot you I gotta say this is some of my favorite background music but anyways at this point you've acquired yourself a blue ball or more likely for my audience a pair of blue balls and you've added two markers and filmed your footage making sure that they both always stay in frame now the first thing we need to do is take our footage and convert it into an image sequence so that we don't have any framerate issues and to do this just open a blender head over to the video editing workspace import in your footage from whichever directories they've didn't choose your project and in out points which will affect if we trim your footage and finally pick some output settings so that we can render out our image sequence and now we're ready to actually begin tracking now it's time for us to do our location tracking which means we're gonna take our image sequence and try to match this motion with our sphere and really the idea here is to find the centers emotion so that we can done simulate depth by changing the radius in other words our track isn't actually three-dimensional because instead of keyframing the depth were instead changing the size of our sphere which means all the motion is actually contained in a single plane and you might be thinking okay I guess I understand what he's saying but I don't think that this will actually work and that's a valid concern a valid concern for someone who is stupid and wrong so to do this just open up a new blender scene set it up see up the camera facing one axis import in our image sequence as this cameras background and add in a sphere set to shade smooth which were gonna position in ski to match our sequence and then make sure to keyframe both location and scale where then obviously gonna go a couple frames down and update our sphere so it's matching and then just add another keyframe and we just kinda keep progressing like this which yes takes forever but there are a couple tricks which will speed up this workflow first of all I recommend enabling x-ray with the alpha set to zero which will let us only see the silhouette of the sphere making the repositioning much easier also you shouldn't be going one frame at a time to add your keyframes because it's horribly inefficient and will most likely lead to super jittery results instead you should try hopping every 20 frames or so to get our first pass which we then refine by going back and filling in the midpoints in between to get our second pass and you just keep progressing like this until you're happy with your current iteration and believe me this will save you a lot of time for this manual process and then also for rotation tracking so our sphere is now following the motion pretty closely but you can see we're still missing the rotation component and something like this is fine if we're replacing it with a plain sphere but the moment we add any sort of texture everything just falls apart so clearly there's a need for us to do this however rotation tracking a plain sphere is nearly impossible but luckily for us we did add those two extra markers so what we're gonna do is create a new material set it to show a checkerboard texture using UV coordinates we now need to put our camera background into foreground so we can actually see our sequence and with the coordinates set to local just rotate the checkerboard hole so it's on one of our markers and then rotate about the z axis until we have a checkerboard steam crossing our second marker and finally add a keyframe for rotation and what we've done here is create a system that easily lets us visually line things up and we just need to keep progressing down our footage and again remember that you should be putting down your keyframes often while you say you're going past bypass instead of going frame by frame we've got our footage we've got our track sphere and now the question is how do we composite them together and generally what we're gonna be doing is first overlaying them together then we're gonna key up the ball use this to put our fingers back in the foreground and finally we're gonna bring back our original shading to add some realism so step one how do we overlay to do this make sure to set our background to be transparent head over to the compositing workspace with nose enabled and import in our original sequence so that we can overlay them using an alpha over and that would cool we now have them overlaid but you can see that the fingers are obstructed and to fix this like we talked about we're gonna need a key out the ball and blender has a bunch of different keying nodes we can use but quite frankly I don't like using them so instead we're gonna do this manually one way to do this is by taking our sequence and adding some pre-war Worthen only gonna look at the red channel for this user call ramp note to create a high contrast math thrown some post word add some softening and invert our Matt and use a math note to multiply this with our sphere output which we're gonna soften using dilation now let me ask you a question are you bit overwhelmed with all this compositing well long story short this node network is just an anti so a tower sphere without the fingers so what we can do with this is use another alpha over notes to bring our fingers back into the foreground which means at this point we've integrated our render into the sequence and the last step is just fixing the lighting and how are we gonna do this well you can just again blur out the sequence isolate the vibrancy Channel mix this with our node network with the mode set to multiply and finally use one more alpha over note to overlay this back in and there you go this is our compositing node Network feature rich with controls for managing our shading controls for managing our sphere matte and controls for I don't know I hope you enjoyed this tutorial found some value in it because you're certainly not gonna find any value and yourself so he now know how to do sphere tracking but do you know how to create a beautiful website no well the sponsor for this video Squarespace has you covered that has a super easy to use website builder which in fact I used and currently used for my website www.marykay.co.uk/awilliam see can send your individual or brain message and donation collection if you do something that people would want to donate for and yeah Squarespace is already super affordable but to swing the deal a bit if you go to my link in the description right now and use my coupon code you're gonna save 10% off your first purchase of a website or domain

Channel: CGMatter

Views: 272,427

Keywords: blender, sphere, tracking, tutorial, motion, 3d, camera tracking, vfx, cg, cgi

Id: 6PjHVHxbwnc

Length: 6min 3sec (363 seconds)

Published: Tue Apr 07 2020