Blender Supervised Tracking and FBX export to Maya

okay so in this video demonstration i'll be showing you how to track manually this playground sequence so first load up your vfx motion tracking and then click on open and locate the image sequence so this is the sequence that we are going to be tracking click on the first frame sorry not this one let me just reopen another one this one the playground okay and then we're going to click on this set scene frames prefetch so you load up into the memory and next you'll notice that the image is a little bit washed out we got to change the colors so go over to the color management under the render properties and then change from filmic to standard and then now we can decide how we track this sequence okay first we need to observe and check this sequence right for good patterns to track now for this type of environment right the type of best tracking motion model would be perspective or a fine location and all the way the location rotation scale will be very fast but it might not be the most accurate okay so i prefer to use perspective for this shot and then for match i use previous frame so that you use the previous frame of reference before it tracks forward normalize so that each frame right or each frame as it tracks right the lighting will be equalized right or normalized and then for the tracking settings the correlation can be set at 0.9 for higher accuracy margin you can put at 25 pixels so that when the tracker needs to reach about 25 pixel next to the border it will stop tracking okay so with these settings on uh i'm going to increase the tracking pattern size from 40 to 110 for the search size and then we can start to pick up our first uh track point so i'm going to pick this leaf this dark shadow the tip here as my tracking point of interest so holding down the control and left mouse click to create a tracker point over the area so now we're at frame one now i want to see the search area so press alt s to bring out the search area now if you take a look at this angle where the shot is being taken you can see that there's a perspective perspective distortion over here so i'm going to change the shape of this tracker so that it matches the perspective distortion of the tile here if you take a look at this tile here you can see that at this angle the distortion of the perspective uh shows it like that so this is why i'm changing the area of interest to look like that if you click on the tracker tab here you can see that this is what you look like if you're looking from the top view of this leaf here okay so as i adjust this you can see that it's now being redistorted to match the vertical view from the top so with this on i'm going to increase the size of the search area and then i press ctrl t or click on track forward to track this shot now if you want the tracker to be visible in the center you can just press l to lock it and then so that you appear in the center and my tracker has stopped at this frame because of the motion blur so if you see a motion blur you can just use your cursor to navigate to the next frame then click on this track window here and then can click and drag the track window to match it to this the previous frame and you want to use your cursor to navigate left and right the previous frame and then the manually planted keyframe to check that it matches the correct position so go to the last keyframe and notice a diamond appears in the dope sheet this is a keyframe that i manually added then i can track forwards and it should track all the way towards the end okay so now yes manage to track all the way to the entire timeline you can left mouse click and drag the timeline and then just inspect and check that the tracking point is staying put at the position that we want okay there is a bit of slide due to the motion blur but that is fine so then you can click on the lock to lock it in position okay next we're going to track this pattern here okay there's a very obvious corner here and then i'm just going to use a bigger search area and then stretch this to match the perspective of the pattern like that okay and then we are actually right now we are not at the first frame so i'm going to track backwards and click on this button to track backwards so if you want you can actually start from the middle and then track backwards then you go back to the middle again and then track forward so i'm going to click on the timeline here click on the number region so they can uh drag to the last frame that was being tracked then click on this button to track forward giving him an eye on this track area here okay this one right the track point of this corner here is gonna disappear so we're gonna leave it at that then we can lock this track point here ideally right you want to try to search for points that appear all the way from beginning to end so i noticed a leaf cutting this edge here so i'm going to use this point as my tracker i'm going to press s to scale it up slightly this time i don't want to adjust the perspective maybe just adjust a little bit like that just to match the perspective shift here then track forwards and again because of the motion blur then it goes out of view so i'm going to click on this track window and then manually adjust it until it matches the blur position which is around here then continue the track all the way towards the end okay another blur motion blur or sometimes because this edge is nearing the search area so we're going to increase the search area a little bit that will add another keyframe and then we're going to track forwards okay so it tracks all the way to the end now we scrub backwards until to the last frame then i'm just gonna increase the search area a little bit and then track backwards okay motion blur again and let's see whether i can change the shape a little bit maybe increase the area of interest see whether that will continue to track backwards okay it doesn't want to track uh forwards so we have to manually move it into place and again use the cursor key left right left right to check the previous frame and then the next frame okay i think i move that too too high just maybe right about here okay this is good then continue the track backwards okay so again another motion blur okay we're gonna click on this frame the last frame and then i'm gonna manually move it into place okay and then let it track all the way to the end okay this time i want to change the shape a little bit and then hopefully it will continue to track okay this one no choice i have to manually put it into position i think it should be here okay then continue the track okay what you want to avoid is that you don't want to put too many track points close to one or other key frames close to one another right then we can scrub back and forth and then just check and then this one looks good then we can lock this so we got five more points to go now if you want to move at a faster pace you can also uh start with multiple points to track first for example let's say i track maybe i start with two first i want to track this point here and then i want to track this this leaf here okay maybe on a track it's shadow because it's dark and contrasty and maybe this one is a little bit too big just make it a bit smaller okay select the bottom of the leaf here then with all with both these trackers these new trackers then selected then we can track forwards okay one of the tracker point has already stopped tracking so we will continue with this one first right now this one has stopped tracking also because of a motion blur okay no it's actually not a motion blur it's because my search area box is now too small so i'll just give it a big bigger search area box then i track forwards okay this one is a motion blur so click on the search box and you can manually move it down okay use your left right kasa key to check and then lay track forward okay maybe i'll have to reduce my correlation because right now the correlation is causing the uh tracking to stop too soon okay maybe i'll go over to the tracking settings the tracking settings correlation bring it to 0.75 which was the default so give it a little bit more leniency in tracking and let's continue to track hopefully it doesn't stop so 0.9 might be a little bit too strict that's why the tracking stops okay so we can lock this one let's go back to this one uh it actually stopped tracking right about here so again the correlation of the factor uh maybe bring it down to 0.75 increase the search area a bit and then let it track forwards okay the edge is going to touch the search box it's going to stop okay so i'm going to increase the search area box size and also maybe reduce the area of interest okay same thing increase the search area box then let continue to track oops i'm searching the wrong in the wrong direction press escape okay let's track forwards okay then this one actually goes in all the way nicely so let's lock this and then i want to change my correlation this time to 0.75 because 0.9 is too strict that means that if it doesn't match the previous data it will just stop tracking so right now we have five track points we need three more to go so i want to track this point over here okay there's a dark spot over here i'm going to track this dark spot let's take a look a closer look at it okay and let's change the shape to match the perspective okay then track forwards okay increase the search area okay change the shape of this area of interest and then continue to track okay so this this one is motion blur quite badly so you can click on here to move the track point here increase the search area a little bit more and then hopefully it will track all the way to the end and which it does okay so let's see all right there's some a little bit of shift but that should do okay let's look for another track point okay maybe this one here this one is a good track point ctrl left mouse click scale it up a little bit okay maybe i want to track this tip here where you see a color transition and let's track backwards from here okay the area of interest is touching the search area so let's increase the search area box and then continue to track all the way okay now we scrap to the last frame before we started to track this and then we're just gonna let it track forwards i'm gonna increase the search area a bit and it should track all the way to the end okay i see a little bit of sliding there so we're gonna fix that go back just a point just before it start to slide right about here then you can delete all the track information and then maybe we're gonna scale this up so that it has more pattern to track and then let it track forwards and then we have a much more accurate track okay now we can lock this one okay we got six seven okay we just need one more one more track point so i'm going to track this leaf here this green leaf here so i'm going to start from the center so i can see it a little bit clearer holding down control left mouse click then scale this up so you can see the green leaf i'm gonna track the edge of the leaf about here and i'm gonna just track forwards okay the motion blur cause it to lose track so manually move it back into place click on the center move this back into place use the cursor back left right cursor move it into place maybe just move this up slightly then let it continue to track and because of the larger search area you can see that it slows down quite a bit we might not have this issue with the location but location might not be as accurate so we're gonna just track backwards okay we have a motion blur activate another keyframe and then manually move it into place okay you can see the yellow zone is starting to appear but this area here is not still red because the tracker only ends tracking at this frame so we need to put another tracker that will run across the entire timeline and then we will be ready to solve so let's go and look for another good track point and i see one over here holding up control left mouse click and then we'll check this dark patch here increase the size slightly and then just gonna start tracking without adjusting the perspective okay so now i'm going to go back and maybe change the shape a little bit of the area of interest and then i'll just track forwards okay so i'm going to change the shape here a little bit maybe change increase the search area and also the pattern size and then search and then i think that's it okay so so now you can see everything is not in the yellow zone now there is a few frames right about this area here that is still showing red that means right i'm having some back tracker points here okay i got a tracker right that is disconnected which is tracker number four so go over to this frame here this is tracker number four so let's click on tracker number four and then let's try to bridge the gap here so i'm gonna track frame by frame to connect it all the way right so now it's connected and then we can lock this and now everything is yellow we can now solve the scene now before you solve always save a scene i'm going to save it as tracker version number three and hit solve so if you solve without putting in the correct keyframe you're going to get a very high error value right now there's no parallax motion in frame 0 all the way to frame 40 so 1 to 30 is not a good number in fact let's just solve and see what happens we'll get up an area actually it's 16.3 but still it's still quite high so you can see the curves right is giving you this weird patterns okay since i've solved this area quite the number of times the best keyframe right is actually around 70 to 90. right right there's some forward movements and then there's a side slide side movement that shows on parallax so 70 to 90 okay would be a good keyframe and then i hit solve okay i end up with a higher error instead okay so in this case right maybe it's the combination of the different trackers that is giving me this problem so i'm gonna try another range maybe i'll try uh 100 and i'm gonna sorry this is 165 okay so i'm going to press shift s and then use the pi menu to select keyframe a and then maybe a move a few more frames forward and keyframe b at 173 and then i'll solve okay actually it's got worse so i will try to find a better range okay okay uh sometimes you have to keep looking for the good keyframes i'm gonna try 50 60. see whether i get a good result or actually that's worse 60 to 80. let's see that okay that's even worse so maybe uh 70 to 85 146 now we're getting somewhere maybe 38 okay we're not getting uh some good results here maybe 75 to 95 53 and you can see the bumps are going up and down so sometimes if you and if you've got this kind of problems right you might have to put in more track points that means your the quality of my track points right might not be that good okay so if you get an error that is this high okay so sometimes it's just because uh the we don't have enough parallax information right to solve this area okay maybe i'm going to try another different region here okay this one is a and then maybe b let's try this one three okay we are making good progress so right now i managed to get the error down so that's why sometimes you if you only have these few tracker points right you might have to go and search the best keyframe range so once i got this keyframe range it's a getting an error of three then i can now activate focal length and then hit solve and you can see now i got an error of 0.62 so um i can refine this further by looking at the dope sheet and in this case right tracker number six right has the highest error so i can click on tracker number six go to tracker number six and then uh under it's uh what i call his weight right we're going to bring it down to the software bring it down to maybe 0.5 that means we're going to give it about 50 priority in solving then i'm going to hit solve again so 0.6 i managed to bring the error down to 0.51 pixels which is i think for this purpose is is good enough all right so now that we have solved this we can solve you can save this file uh we can save it all right and then uh just before we lay it out okay we want to first establish where is the floor so go over to the orientation select three points three trackers rather holding down the shift one two three make sure that they're quite far apart okay maybe i'll select these three points instead and then i'll say that this is the flaw okay right now the orientation is set to the floor and then i can now click on one of the points let's say i want to set this as the origin so i set this as the origin right now my scale looks a little bit too big so i need to select two points shift holding down the shift select two points and then maybe the distance i want to set it at four units okay four units between these two points and then click on set scale okay then finally i want to set this as a background and i'll set up the tracking scene okay next i want to set up the axis now i want this line across here to be the x-axis so i'm going to click on this point this is the origin so on the right-hand side i want to set this as the x-axis okay so if i scrub my timeline right now the camera will be constrained to the motion tracker as you can see over here now if you want to fine tune it like i noticed that my x-axis is not really lined up with the uh the straight edge of this playground floor go over to the layout and then go to layout tab then look through the camera by clicking here you can also increase the color of this backdrop by clicking on by selecting the camera you can select the camera outliner here go over the camera tab go to background images and then check up the opacity you can turn on x-ray by clicking on this button and then with the camera selected you can click this drop down menu and click on 3d cursor so that when i rotate you can use the rotate tool here to rotate to adjust okay but i find this rotation a bit finicky i prefer to use the shortcut tools in blender so you press r followed by z so that i'll be rotating along the z axis okay so you can scrub the timeline and then check whether your perspective line the edge of this floor plan is it matching now if your floor plan is too small you can select the floor plan and then you can press s to scale it up and then you can see whether it is it lining up along the tile properly okay so this one is lined up i think everything is lined up perfectly so now i'm going to select this cube press g followed by z1 so that it's sitting on top of the surface and now i'm ready to export this up to maya to export it out to maya first we save as a copy first for this version i want to call it underscore solve and then click save and then i'm going to now export this now before you export this you need to detach the constraint of the camera so select the camera click on the constraint and then uh convert this constraint of the camera movement into a into into actual movement because right now it's been constrained to the match move so we need to click on the button constrain to f curve okay once that is done if you change if you see the graph editor you'll notice that the selected camera is showing the actual motion curve previously before the conversion right or before being attached to the f curve you don't see this at all so now we are ready to export this into fbx okay so to export to fbx you just click on file export fbx and make sure you change the scale value from 1 to 0.01 i find that this is the best skill settings then if you click on the big animation settings the simplify change to zero now if you don't if you don't change the simplified to zero it's going to look at your curve and any any noisy areas right or rather any points right uh that look looking very similar you actually reduce your number of keys for you actually we do not want any keys to be reduced so we need to sample it at every frame and we don't want to simplify then now we can export fpx then now we go to maya launch maya um okay so now we can bring in the fbx so of course you need to set your project first um i'm just gonna import it straight away and then show you what other things you need to do next so import okay go over to the folder containing the exported file which is this one fp accent import the first thing you notice that the camera is very big and if you scrub the timeline check the frame rate uh is actually exported to 25 frames okay i think if it is not that means i did not set my frame rate right at the beginning yeah that was my mistake so the frame rate here was 24 frames but actually the footage was shot at 25 frames per second so just make sure that your frame rate is correct so anyway uh my blender was set at 24 frames so it exported to my fbx so it's 24 frames so we'll leave it at that and now select the camera you want to break the scale of the camera otherwise right if the scale the camera is too big you will not be able to see your image plane so select the camera go and highlight shift select all the values of the skill right mouse click on it and break the connections then change the value to one right so select all the values and change it to one look through the camera okay so that now when i scrub the timeline we are seeing what the camera is seeing and next we go and click on view image plane going import in the image sequence okay click on the first frame then click on the image attributes and then click on use image sequence now if your frame rate everything's been set correctly then if you scrub the timeline everything should match nicely so that's how you use the powerful tracking features of blender and then use it in conjunction with other software like maya in this case so at this stage you can bring in any other 3d models render and then complete using another compositing software

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Id: xUX3tOn3LZM

Length: 30min 44sec (1844 seconds)

Published: Fri Jun 11 2021