STMap in nuke : how to use? and when to use?

hello guys today we are going to see the St map what is the St map and how to use HTM app and when to use HTML so as you can see in my new the benefits of using St map is we can do a warp distort match move stabilize and texture apply and the texture apply we are doing when we're doing a CG company let's go step by step so what is the Steam app basically St map is they look like this so it's representing the green and red channel so if I press R you will see the red channel in in this Ram so this red and green combine you will get the St map which is storing the pixel information in the current position just like the transform if we add a transform is saying translation 0 and 0 so we are not changing any value if I move this now we are changing the pixel values so the same thing happen with the SD map we have to generate a St map and then we have to this HTM apply the effects this is the St map node so you can see this one but before going this one we have to know how to generate HTML and how to do the manipulation to apply on on our image with this expression as you can see you can create the SD map for double click you will see the what is happening in this you expression mode so basically in the X in the X in the red Channel we are adding a ram X Plus 0.5 and width basically the width and the height in the in the green Channel and and that's it and you have your St map ready to use this is the way you can create SD map and let's see how to use this SP map so I have a few examples here the simple use case of this SD map so I have this checkerboard here and I have the same expression I added here and I have a noise here also they just noise and I'm multiplying on the St map so if I gamma down you will see I am changing the values so if I sample this current pixel value as you can see the red is this values now before is this so I am changing the pixel value which means we are changing the translation of this St map I can play this St map and connect the source to the image and HTM app to St map and then in the channel I have to set the UV Channel or GP because the SD map is RGB so now if I view from here you will see this is the whopping and stored starting the image based on the noise so if I come to the noise if I change the scale you will see it's getting more and more details I zoom out and you will get very a big noise and in the multiply you can't control the effect also see like we can increase slowly see and it's whopping like that [Music] so let's see you like this one and if you want but this is a very high frequency noise as you can see and and low frequency also but if you want to reduce the high frequency noise what you can do you can add a blur so benefits of adding a blur it's very very very important very useful we will see in the I will show you the best example but in this one if I blur this St map like here you will see we are removing basically we are blurring The High Frequency detail as you can see and we are reducing the details and we are just making the St map very smooth see six before and after so and another use case of this St map you can do you can add a length description so in the new many nodes are supporting the St map just like as you can see just like this Len Distortion node if we open the properties assume you set up the all the link Distortion and all that and in the output is basically uh give you the undistorn and redistrot but it also have the St map output so with that one with storing the St map detail in the motion channel so give the motion Channel you will see see we have this St map the red and green we can just Shuffle out the St map and using the St map node we can apply the link Distortion so benefit of doing this way you can render this path out from here and you can pass it to someone who's working on yours working on the same project you can pass this St map and you can also apply using this one this node is also reporting and also the smart doctor node also support the SD map when you when we create a smart Victor like here and then you can use the vector distort when we using the vector distort node in the vector Discord we have a St map so you have this output estimate and after that you can apply the same here and it will affect the benefit of doing you can render this path out and you can save it save it in your drive and you can use it anytime and it's very lightweight because you render out the smart doctor thing using the SDM app this is your converting the smart Vector into the SD map and then you are applying the match and warping the result will be the same but it give you much faster speed to work on like this way so now we know the St map uh what is the HTML and how to use the St map here are some more 2D examples uh after using the St map in real world case so as you can see I have this image here oh this lady I want to change some definition of his face so what I did here I take the same St map and the rotopen node and I did some changes on his face if I show you for Honor you will see I change some definition of her face let me see what is happening here I'm basically whopping the St map and this effect will apply on this image as you can see this is another use case you can directly do that with the Roto pen but so this is the another way of using the St map as you can see if I show you if I want his eye maybe this much so as you can see now we can warp and distort image using this Roto paint node and SD map in the in a 2d environment like this and the same thing we can do so as you can see in this one I'm directly adding the this thing right here on the rotor pin node and in this example so let's see I want to decrease or increase Roland so in this one what I did I have the same HD map I added a transform so as you can see in this one I am making the HTM up and I'm key mixing with this one with this rotor so the effect only applies here in this one so as you can see now again the pixel values please change before this 4 6 now is change 4C set and one two so as you can see the values are chained so this will detect from this St map and as you can see we change face uh jawline with definition of s and in the earlier I told you to use the blur so see in the Roto note I have this much color here and I'm adding a more blur here if I show you if I disable the blur you will see the hard line and all it will not gonna blend properly and same thing here if I just select all these things and remove that this blur mount you will see what is happening disable this thing see so now the Roto don't have any blur but we are just cutting this like this and we are applying the St map it will give you the effect but it's not blending if I add a blur now you can see the difference I disable the player complete if I increase see it's blending through this [Music] so let's make this 50. see as you can see now it's proper C if I check here it's blur it's not the same as we are doing the transform Mass Transformers will give you the feather like uh transition but this one is blending because this is the HTML you are basically whopping and distorting so this is the basic concept of using the SD map in your 2D environment main benefit of using St map you can store this information and you can use it later and you can use it like this the key mix and blur and it will give you the very nice result like this so in the 3D environment how you can use this one there are many ways to use this one let's see the in Nuke we can how you can use this one and then in the 3D environment uh how you can use this one when we are doing a CG company so I have another example here right here I have this footage if I play for you I have this footage of this mountain the Drone shot and let's see I have I have a match move camera which I have here and I want to play something over here here and here you can easily do that but how to do with the HD map what I have here I have this St map and I'm projecting this one I also already made it a geometry of this environment as you can see feel the basic geometry of this scene so I have this project 3D and I'm applying this St map on the camera on this camera so now as you can see we have this uh projected on this Frame Zero from this camera and then I'm rendering this one out so it's look like this now this St map is tracked as you can see it's moving so as you can see this St map is moving now okay let me quickly add a frame range node here okay so as you can see it's moving because it all is tracked with that camera also so what I can do if I come here and the St map I can see uh I want to add some and make this our CPA so now this shape is tracked with that current motion it's like 2.5 D tracks so as you can see it's going with the perspective also it's not the same so if I disable this one so as you can see the perspective is also changing this is the another benefit of using the SD map we can store the tracking information in 3D space Also as well as in 2D all right so let's move on to the CG uh CG environments so let's consider we have this footage and let's see we have we have a track on the space and we have a CG uh you know CG mask on his face and but we need to add some texture on the space so uh to manipulate uh to apply a texture on this face I basically uh did render so basically I have this 3D face using the model builder and face tracker so I have this Mac move face on on her and what I am doing here doing the same thing I am applying a texture I am applying a same this expression HD map and applying on this face as you can see directly and and I'm rendered rendering this one in the CG in the CG company you're also getting this kind of map and that one called the UV map you will get the same path like this one in the name of Vue UV password UV layer or something like this the idea and the concept is the same you can use this one you can add texture and surface imperfection to your CG to make it more realistic so in this one we are adding a texture using this information so using the same St map and the text see as you can see I'm applying using the same SD map and this one is tracked with with her face as you can see there is one problem you have to know the exact position of of her face so what I mean by that see if I have this text like like here but remove these things so I have this text here and let's see uh I want to add this text on like let's see here here for example so we we can randomly move like this and we can apply like I'm doing like here so yeah this is the exact position but uh this is not the proper way to identify the exact position of her face and of her face or any any other CG object so the best way you have to know uh the UV coordinate of this CG object so in this case I have this face so I have to know the UV of this face so I can apply that can also render the UV map is basically you can you can also make this UE map if you have a CG object and you can also do in the scan land enter as you can see if I disable this one file so this is the UV it's looking like so I'm applying the wireframe to show you so this is the uh face unwrap of this model so basically we are unwrapping this face on a flat surface so it will look like this so in the scan line don't connect the camera just connect the object to the scene in the projection mode just set to UV instead of by default it's the render camera you have to set as a UV so then you will get this uh but in the all 3D program UVS in a square format I have this 2D reformat I'm connecting to the pg so and now it's more uh more Square so previously small stretch because we have this HD format so on converting it to 2K so now you can see it better the all the shapes and geometry of this face so with this we can use as a reference so as you can see I'm adding this text as here and let's see now we can freely move this like I want to place it uh like here in this case I want to place on here on this position now I we are referencing here and as you can see in this 2K square box the the exact position of this area is here so if I apply this on St map moving here so let's view from here now as you can see it's properly applying on this position so let's go back to 2D and let's move maybe like here on the notes and let's view it here so as you can see it's properly wrapping you can manually do this like in the in the viewer also like this but sometimes it's very hard to pinpoint exact position so this is the best way to align your texture like text or you can add a noise and something any anything you want to add you can mask this thing all that stuff and then you can use the SD map and AKA UV map in the CG company we called the UV map because it comes from the 3D package you can also call the UV map so as you can see now it's applying and it's also match moving as you can see [Music] summarize everything St map is just a ram in red Channel and a green Channel which is storing the current pixel information and you can use this to basically warp and distort your image and you can do match move with the like I'm showing here and you can also do into Point 5D using the smart Vector thing very useful uh in many situations where you where you want to store the data you want to store the tracking information and and texture texture information you can use the SD map if you have any questions please let me know about the Steam app and any any future topic I will try to make it as soon as possible thank you for watching

Channel: VFX SHOWDOWN

Views: 16,961

Keywords: adobe after effects tutorial animation, Adobe, after effects tutorial, Redshift for cinema 4D, adobe after effects, realistic, devin graham, 4k, insane, Volumetric light effect, new dji inspire 2 zenmuse x7 6k camera, new camera, inspire 2, after effects, Nuke Compositing, keying in nuke, nuke vfx, vfx, compositng, CG compositing, Nuke CG compositing, nuke stmap, STMap in nuke, how to use stmap, nuke live compositing

Id: pwSFZOwTc98

Length: 17min 1sec (1021 seconds)

Published: Sat Feb 18 2023