Nuke Tutorial: 3D Projections Made Easy!

hey welcome to a new tutorial here today we're going to be giving this guy a hand with his home design choices by learning about patching through the 3D camera system so I got my denoise plate over here and as usual we got a bit of lens Distortion to handle if you try to draw an imaginary line across the screen you can see that what would be a straight line has a bit of a Bend to it and there's three things we can do to handle this if we had the lens specs we could totally pass that into the camera tracker in a couple of ways and that would solve the problem but we don't we can either let the camera tracker slow bit or we can do it ourselves sometimes one's better than the other it takes a bit of experimenting to find the best result for this tutorial I'm opting to do my own camera Distortion so we're going to try to understand it in the old way we're going to call a legacy note called the lens Distortion so we're going to press X and then we're going to type lens Distortion here just as it is we're gonna put it right below the plate we're gonna go to the line analysis section tick the drawing option and now we're just going to be marking a path over an area that should be straight but isn't because of the Distortion of the lens such as the edge of the house the frame of the door the post or the Garden Wall on the side so I marked my points just by clicking and once I have my path ready I'm gonna right click and it's gonna draw a line so we're gonna draw as many as we can either vertically or horizontally to give the node enough information to solve the Distortion pattern with a good amount of lines set up we're gonna hit the analyze button and we're going to check the result you might need to try this a couple of times until you get a result where the image information that you have on the edges straightens right below our lens Distortion node we're going to create the camera tracker and by this point you might get the impression that there's a lot of menus and complicated buttons all over the place but you're only ever going to mess with a couple of them and that's exactly what I'm going to show you anyways go to the settings tab and click on the preview features while having the viewer on the camera tracker you'll see that the area is populated by points which will be used to track the footage we're gonna change the number of points to a thousand and we're also going to turn on the refine features location which pretty much means that we're asking nuke to actually do a bit of thinking before placing the points so that we can actually grab good tracking areas as opposed to random ones so we're gonna adjust like the minimum length to 15. so what that means is that any given point to be considered valid for this camera track has to be consistently good for at least 15 frames with that said we're going to go back to the mean tab and hit track once we cut the track down we're going to hit solve and as you can see our track came in with an error rate this is normal now we're gonna try to reduce the error by going to the auto tracks tab and adjusting the Max and track error what happens when we do this is that we start rejecting points that do not meet the criteria that we're asking for here we want to bring them down as much as possible while keeping a good chunk of points so that we can actually play around with our 3D scene right I'm going to click delete rejected and delete unsolved go back to the main Tab and click update solved our salt error has now changed the lower the solve error is the better moving on on the expert section I'm going to select scene plus create so what we got here is our 3D camera setup I'm gonna remove this lens Distortion thing over here taking advantage of the connection to connect the plate to the 3D scene through a merge I won't be explaining the magic behind all of this now we're going to go straight to creating our first projection now if we set the viewer to the scan and render and press tab we will be able to see our 3D environment by holding Ctrl I can rotate around the environment and take a look at the points that we created they represent the house that we were trying to track now I'm going to create a card node you'll see it pop in the viewer right away and I'm going to adjust its position to match the geometry that this collection of points is trying to create and all I'm doing here while having the card selected I'm dragging the axis and by holding Ctrl I can do rotation now that I've adjusted the position of the card I'm just going to make it a bit taller and then I'm gonna connect the card to the scene I'm going to create a frame hold set to 218 I'm going to connect it to the undistort node create a roto do this shape pre-molded then I'm going to create a node called project 3D and I'm going to connect it to the pre-mold enter the card copy paste the frame hold connect it to the camera and I'm going to connect the project 3DS cam input to the frame hold so what's going on here is you're telling nuke hey I got this image that belongs to the point of view from F to 18. so then nuke is going to grab the card that we made and display that image from that point of view so that means that if we actually look at the resulting image coming from the scan and render at that frame nothing should change except for the difference in lens Distortion but that's something that will fix up ahead but whenever you go to a different point in the timeline you'll see that our image adjusts to a new point of view based off of that original reference point from F to 18. so that's essentially what projections are you got the main camera here simulating the movement that we're seeing in the footage and then we got a projector here which is essentially a copy of the main camera Frozen at frame 218 projecting onto our card which allows this whole perspective magic to happen now to complete the projection if we go back to frame 218 and compare the plate with the projected result you'll see that there's a bit of a mismatch because our projection is not distorted so what we're going to do is we're going to copy the lens Distortion and we're going to paste it right after the scan line render we're gonna uncheck the undistort option now if you compare you'll see that there's no difference between the original plate and the projected result now we're going to finish the paint aspect of the tutorial for beginners it might be tempting to create a paint node and start cloning away well that would work it is quite hard to paint in perspective so now I'm going to show you this little trick to fix that you're going to create a corner pin deactivated and then we're going to drag the points and try to simulate the perspective that we're seeing on the wall I'm just going to use the wall itself but you can use any other area that you want that will help you match the perspective once you've done that you're going to check the invert button and reactivate the node and there we go with the perspective fixed to recover the image we're going to create a reformat node set it to scale and resize type to none then you're going to scale it up as much as you need to to reveal your work area and to finish this setup we're just going to invert the whole process I'm going to create a reformat node again set it to type to format and resize type none copy and paste the corner pin and uncheck the invert box now if you compare the frame hold and the last corner pin you'll see that there's no difference so we successfully brought everything back to the way it was having that we can create a paint node and start cloning away I actually went ahead and created my own version of the paint out here it is so with that done we're going to visualize the result that we have it is almost there it just needs a couple of adjustments we're gonna do some color Corrections add a great note after your paint we're going to give him the gain at 218 leave it as is go to the first frame I'm gonna bring down the gain to match the brightness at the top area of the patch I'm noticing that there's a bit of a difference in color so I'm going to bring the green and blue channels down a bit now that blends way better The Next Step we're going to create a ramp node take the replace option connect it to the grade create a new grade node after the one we have mask it using the wrap node just like before we're going to keyframe f128 N1 we're going to go to our ramp node we're going to drag the line it makes onto our image if you're not familiar with this node it is pretty simple it creates an alpha layer for us that directionally changes in value if we look at the points on either side you'll see that we have zero where null of information exists and one where the alpha value is at its maximum and what we have in between is the gradual change in values either to maximum or to nothing and this is very useful because you can use it to mimic Shadows or create light Fades which is exactly what we are about to do now back to the plate now we're going to increase the brightness at the bottom of the patch and gradually decrease that effect as we make our way to the middle of the patch so I'm going to adjust the gain to 1.2 on frame one next up we're going to create a blur after a roto node set it to 9.6 affecting only the alpha so now right after our lens Distortion we're going to create the focus node and we're going to animate frame one set the focus level to 0.1 then go to F to 18 and set it to zero and now we can preview the final result from this point on you could actually make this more interesting by integrating an element into the plate such as graffiti but we'll leave that for another occasion thank you for watching hey guys I'm checking in here with a special announcement I'm offering a live course designed exclusively for beginners or anybody wanting to start from scratch it is an awesome opportunity because I know how difficult and time consuming the beginner stage is as a newcomer not only are you always finding yourself to be lost and confused but also unsure about whether what you're doing is actually correct and all this can be extremely demotivating but it doesn't have to be this way and that's my goal to make this a fun and smooth experience and on top of that give you the assurance that what you're doing is actually correct and unfortunately I can only take a small number of people because I want to make this as personalized as it can be if you're interested in this go to learnbfxcom.com slash cores or use the link below to check out all the information about it if you're interested in following along for this tutorial or any other in the channel I got you covered sign up to the email list at learnbiefxcomp.com and you'll receive access to all of the files you need for the tutorial including the exact video file I use and one last thing if you're enjoying the content so far please do me a favor and subscribe to 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Channel: Learn VFX Compositing

Views: 5,451

Keywords: learn nuke, learn 3d camera tracker, learn projections, nuke cards, nuke paint, nuke compositing, nuke roto, nuke learn easy, nuke 3d, nuke tutorial, nuke course, nuke bgprep, nuke tracking, nuke vfx, vfx compositing

Id: EOokBl3OeSw

Length: 11min 38sec (698 seconds)

Published: Mon Jun 05 2023