Category: NUKE

This week I completed the entirety of the Fall of London project, successfully synthesising the flames as well as tweaking the values of the various values such as the nuke explosions, and had my assignment critiqued by Gonzalo in class, who asked me to make a few tweaks later on

Here’s the full video presentation

I added the nuke fallout cloud and made it appear behind the nuke mushroom cloud, here I used the built-in tools in the node to make a change in the order of the masks.

Then I made smoke trails on the windows, mainly using the Grade node and the Roto node, and imported the flame material into NUKE in 3D mode

I then made a Glow node for the flames, but I found a softer alternative that automatically calculates the environment around the object to generate a more realistic effect

It’s a smoky wall effect.

What follows are some minor corrections I made after my teacher’s critique of my work in class.
Firstly the nuke explosion, Gonzalo noticed on the big screen that some of the debris ran through the mask and into other places

Then there’s the flaming windows, and I’ve augmented the effect of the flames on the surroundings

Then I redid the trace on the shard building, which is now jittery, and the changes will fix some of this

There’s also the bright part of the bomb when the nuke explodes, and Gonzalo and I said that flame compositing is one of the most complicated steps in NUKE because we don’t know how this flame will actually look to the human eye, especially with explosions, and it’s generally hard for designers to match the brightness of the centre of the explosion. But I still think the centre of my explosion is currently too dark, and then the rest of it is too dark, so I tweaked it again

I mainly used the Keyer node to draw in the brightest part of the inside, and then used the Grade node to control the brightness and colour of the brightest part.

Then I found that the ColorCorrect node would cause white edges to appear on the edges of the screen, and by looking at the Blue channel of the screen, I found that it was because changing the value of the highlights would make the black part of the edges turn blue (because the original value there was not 0, so it would be very obvious when the contrast was adjusted upwards), so I cancelled the adjustments related to the ColorCorrect node.

This week Gonzalo suggested a few changes to my video, which I optimised and tweaked, and I created a couple of new effects, and next week I’ll start working on the near window flames and the explosions!

Firstly, thanks to the development of human civilisation! the almighty AI helped me to draw a couple of broken houses as well as some flame effects, which I exported later on

Then I did a Roto of last week’s ground breaking effect

Then I did a Rotopaint of the original frame and made it work to all frames

Then I adjusted the size of the smoke in the distance as well as the colour

Then in the middle of the lesson, Gonzalo said that it wasn’t enough to have this house in the picture, because now it looked out of place, so I made the house next to it a broken effect as well
And because the house was obscured by the foreground, I created an additional Roto.

Adjusted last week’s Roto, where it is now obscured by the picture of the broken house, and I Rotoed it back in the back

Then I added the effect of bullets shooting towards the sky in the centre of the frame, and looked on Github for an effect that automatically adds a lens vignette

I added a smoke effect to the back of the furthest house and did colour grading as well as Roto

Then I added a big bang at the far end.

Colour grading and screen tracking…

And I’ve also tweaked the debris of the Shard Mansion, I’ve removed a lot of the extra breakage effects and modified the foreground fog so that now it doesn’t have a black edge to it

After three weeks of preparation, this is where I officially started to create the big term assignment that Gonzalo set at the beginning of the term. This assignment will use all the NUKE knowledge we’ve learnt so far, so I’m going to be putting a lot of effort into it too!

In preparation, I would like to add smoke, flames, shattering and explosions to the picture, and I’m thinking of making a shockwave of a nuclear bomb explosion at the end

Here’s a sketch of my intended effect

My main reference was wanting to replicate the nuclear bomb explosion scene from the game Call of Duty 4 Modern Warfare, the video below is the reference

At first I added a fog effect, I used ROTO and traced the scene

In the fog composite, I colour-blended the fog with the original image

Next I used the same technique to add a second smoke effect to the image. The original video for this effect was in MP4 format, so I first inverted the image and sucked in the LUMINANCE channel.

Next I added a scene breaking effect behind a couple of houses in the mid-ground, after the ROTO I used SHUFFLE and added three GRADE nodes to colour grade the model.

Then I added a fire-breathing effect on the roof chimney of the foremost house

But in the process of doing the flame compositing, I want to make the flame erupt multiple times and add a MOTIONBLUE node, but I found out that after connecting the MOTIONBLUR, the flame clip can only be played once, so I’m going to ask Gonzalo next Tuesday

Here’s how I staged this assignment this week

This fortnight we’ve been learning about flame and smoke synthesis, and our teacher has asked us to complete part of the London Trap project next week!

Fire Part

Notes (VFX effects material site in the file)
1 When keyer snapping the a-channel, you can do a log2lin before to make the luminance data more accurate.
After compositing, if there is anything out of the frame, add a crop to cut it out.
2 When doing 3d tracking, you need to customise the length of the two points, just one, and then customise it in the scene of the node.
3 Add a motionblur when compositing
4 Keyer can select a display model and export it to alpha.
5 OFlow is used to change the video settings of the input source, such as the frame rate range and acceleration/deceleration.
6 When compositing, merge a max to add luminance information to the b (to give more depth to the result).
7 When doing flame compositing, the reflections on the wall are done this way, the original flame material is added to a curvetool, then reset and go! Solve for different frame data (you can see it in the toolbar), then copy the concentration data, then paste it into the place you want to deal with the grade, then paste it into the gain, then right-click and select Edit Expression, add *30. and it’s done. 5.14 email from gonzalo to see)
8 Synthesise the fire first step PLUS a blur flame to form the final fire edge (this has the most detail)
Step 2multiply back to density (reversed)
Third step PLUS on the fire itself (add a plugin version of glow)
And finally PLUS the flame itself after a glow!

Smoke Part

Notes

When creating smoke, if there is no A-channel in the original material, use the Luminance node to draw smoke from the screen.

If the clip needs to be cropped, use the Retime or OFlow node to control the number of frames in the video.

Then use the Grade node to increase the Gamma value of the A-channel in Luminance, so that the result has more detail and does not suck in the background data from the original material.

Then use the Copy node to make the A-channel stick to the original video, Blur the original frame, and Merge an average value to make the smoke blend into the environment.

Then add some MotionBlur or Defocus to defocus it.

Next is a magic operation, you need to re-UNPREMULT the original screen, then convert it to YCbCr format, and then stack it with the YCBCR data of the original screen, so that you can import the colours of the original screen into the smoke, this step is particularly important, even if it’s difficult to understand

Add a Lightwrap at the end to further blend the edges of the smoke into the original image

This fortnight we learnt more about compositing techniques and green screen keying.

PART I: LEARNING

The above picture is about Gizmo node, he and Keylight are different, Gizmo can solve more colour resources, and Keylight is more comprehensive.

The first thing to learn is about luminance, the core of green screen synthesis lies in the use of several nodes in the NUKE, these nodes have a unique role, each play a different speciality, I will explain in detail the special role of these nodes, they and AE’s removal of the green screen of the workflow is not the same at all, the NUKE is more powerful, but also to retain the original image of the movement NUKE is more powerful and can also retain the motion blur of the original image.

The HueColor node is an old friend from our last lesson! In the last assignment, this node worked well with the generic colours of the screen, making objects blend into the environment. And in the greenscreen workflow, it’s a piece of junk, as can be seen in the character’s hair attachment, with all the residue attached to it

In this section, we find that in the green screen processing or colour correction process, it is necessary to DENOISE the picture first, because the noise in the picture can make the solution very inaccurate, because the noise usually carries a triad of primary colours.

Reasonable use of Shuffle for channel separation and re-Merge, you can make a part of the colour transformation, and you can see the picture, ROTO plus multi-channel composite, you can make a part of the colour transformation

Using the Luminance key and adjusting the values to show different colour levels, the EdgeDetact node produces a similar effect (for this concrete wall).

A combination of the above techniques makes the sunlight in the middle of this image huge and magical!

IMPORTANT：

1: IBK stands for Image Based Keyer. It operate with a subtractive or difference methodology. It is one of the best keyers in NUKE for getting detail out of fine hair and severely motion blurred edges.

2: The chromKeyer tends to work better with more evenly lit screens that are more of a saturated color. NUKE’s CHROMA KEYER is that it takes full advantage of any GPU device you have in your system.

3: Keylight: It is a really great keyer over all and does color spill!

4: Primatte is what is called a 3D keyer. It uses a special algorithm that puts the colors into 3D color space and creates a 3d geometric shape to select colors from that space.

5: Utimatte: The advantage is you can get phenomenal keys that can get really fine detail and pull shadows and transparency from the same image.

Keylight is everything! When absorbing the green screen, you can simply set the green colour to 1, so that the system automatically absorbs all the green colour in the screen, and then process the different parts of the original screen RGBA through a Merge node, which will result in this funny image!

The IBK node is a bit more complicated, it requires manual setting of the node content and a step-by-step process to blend the character into the green and then the removal step, which is tedious but the result is ok

Then the real operation, you need to screen for three parts of the processing, so that the result is the most perfect, but also the most controllable, because many times the green screen is not pure green, green screen will also produce shadows, then we need to divide the screen into ALPHA, BG and DISPILL MATTE.

PART II: BASEMENT HOMEWORK PROCESS

Finally learned MAYA’s multi-channel rendering skills, so hard ah, asked three people to learn! But now I’ll be able to make some interesting stuff!

Work with different channels of Shuffle, each Shuffle is processed only a little bit, step by step, don’t rush

Added two LightWrap nodes so that I could make my tank blend in more with the background, and I set it up with a couple of keyframes, otherwise the edges of the tank at the beginning of the video would be affected by that wall error

This week we had a refresher on multichannel compositing and put the results in the basement homework, as well as learning some new techniques such as light matching and shadow compositing in what was a very big and difficult lesson!

PART I: LEARNING

1: Do not change the distortion of the original video when solving using the Distortion node, keep a separate file and name all the videos.

3: In multi-channel compositing, don’t create multiple colour nodes to process a single image (e.g. reflections), just use merge through a single grade or other colour processing node.

4: Grade node in the whitepoint value by absorbing the colour of the screen to make that colour data to zero (that is, to absorb a more average brightness of the region, pay attention to do not let the screen change too much) use gain to absorb the colour A can make the overall picture plus colour A (that is, so that the grades of the screen fused into the background) blackppint to absorb the deepest color of the object, lift to absorb the background of the deepest color, lift to absorb the background of the deepest color of the object. blackppint picks up the darkest colour of the object, lift picks up the darker colour of the background, multiply picks up a colour in the background that you want to blend in.

5: ctrl+shift selects the average rgb value in the frame.
6: Merge (divide) is the B channel divided by the A channel rgb value of each
7: After shuffle(id) and connecting to keylight, you can select a 3d part by changing screen colour

8: It’s easy to change the colour in HueCorrect, select the one you want to change and then hold down ctrl and alt to add a dot on the yellow line.
9: Toe node is to match the original screen melanin, lift to absorb the original screen is darker, you can make the image instantly into the screen (the shadow will not be too bright or black)

10: Exposure node can be used to adjust the exposure of the screen
11: Use the Specular node to connect to the glow node and select the colour A can make the colour A produce glow

PART II: PERSONAL WORK

I tried to use C4D for rendering at first, and the two images above are what went through the OCTANE renderer, don’t they look good! But alas, after my 3 hour long gruelling struggle, I failed! Because I found that the OCTANE renderer, no matter how it is set up, cannot render the multi-channel composite EXR file correctly. Sometimes there is no RGBA image, sometimes there is no ALPHA channel, and there are not many colour channel files such as SSS as well as Metallicity in the OCTANE Renderer, and many of the channel names don’t match NUKE.

The above is an example of what I’m talking about, and it’s not hard to see that there are many channels of files missing from the image on the left, many of which are black. But this is not the most important thing, the most important thing is that if I put the left file into the scene, the scene will contain the bottom and back of the tank’s “ground”, which is not what I want, I want to have the shadow of the tank, but without the “ground”.

Despite the failure, I was able to fruitfully import the wall shattering file I made in HOUDINI for the tank firing into NUKE, yay!

I then imported the tank’s ABC file directly into the SCENE node to complete this week’s stage assignment.

This week we’ve been learning about NUKE’s multi-channel compositing for processing EXR images, and I’ve been doing some preparation work for modelling the underground scene

PART1

The main adjustments I made were to the sports car’s reflection layer as well as the metal layer, which are the two attributes I think are the most important ones in this night image.

And in this photo there is a lot of water on the ground, which reflects the green light source on the left side of the image, so I added green to the Metallicity node to ensure realism.

I tried lowering the brightness of the sports car overall as well as some contrast, but this makes the car very dark in colour, although it would make it look like it blends in with the background nicely.

In the last step, I wanted to have the car’s lights on and add some fog in the foreground and have the light shine through the fog to create a God light, so I tried to create a God light line.

Here’s my final render, I think it still needs a lot of improvement, for example the right side of the car near the camera needs to have more shadows, and then the overall lower end of the car doesn’t feel like it matches the ground, both of which are in dire need of improvement, I’ll be addressing these in the next session.
But overall I am happy with the colour of the car.

PART II

I still want to make something that interests me, and I think this model is more difficult than a steam engine, or some industrial model, and I’ve found that out in the process of making it, there are a lot of difficulties in making caterpillar track.

The first BLOG of the new term was a super hard NUKE assignment, this week we learnt about the MATCHMOVE technique in 3D and completed two classroom assignments!

I was sick in the first week so I didn’t come to class, so I realised in the second week of class that the first week taught a lot of important things, so I studied the first week on my own in class and completed the first week’s assignments without any problems, and here’s the first week’s assignments on display

Here’s how the second week of study and homework went.

In the process of removing the markers, I took a direct screenshot of the ground and walls near the marker points and selected them as textures.

PART I

In class this week, I learnt how to use special nodes to quickly replace something in a video, and I learnt how to remove an occlusion in front of an identifier. And I taught myself some Mocha Pro, which is a pretty handy tool, but I’m still exploring it and haven’t quite mastered it, as I’ll have a video to show below

As you can see, in the video I have framed a particular piece of content, this is so that at a later stage I can integrate all the learning more easily, and also so that in the future I may be able to put it in a portfolio.

PART II

For the balloon assignment I used Mocha Pro for more work, I added a cute little aeroplane to the scene but I still had some problems with the Alpha channel

In this week’s NUKE class, we learned the basics of ROTO and color management (ALPHA channels and other derivatives) and how to use the auto-tracking color tool to quickly and automatically select and track objects in a video that require ROTO, and I’ve come up with a video to demonstrate the stage of that learning.

So here are some pics that can demonstrate my learning process.

While making the video, I found that I couldn’t export a white video mask (with a black background) so I found the Shuffle tool and using it I was able to choose the color that would pass through the node, so nice.