ALWIN FELIX's BLOG

Week 1

Haze and Depth Techniques

• Changing the look and feel of the shot by adding fake haze which gives an illusion of a city being very polluted or in a disaster using simple mask and Colo corrections.

Smoke Luma Key

• Here we have a plate and a smoke with bluescreen, we can use the luma key to get the alpha
• While merging it is better to use the over operation instead of the screen since we already made a premult, so the screen operation will make the smoke more transparent and inaccurate.

• Below is the right method to merge the smoke to the plate.
• We use the edge extend in alpha to get the lost details in the smoke.

Luma key Inverted

• Using luma key the opposite way and exploring some blending techniques.
• Using the blur plate as an average for the smoke to blend the smoke to the environment.
• transforming the layer to a desired place.

smoke LumaKey Log

• Treating the plate as a Log to get more flat and unsaturated color.
• Through this method we can get more details while keying a footage.

WEEK 03

The Lower Third Definition

What is a lower third?

A lower third is a combination of text and graphical elements placed in the lower area of the television screen to give the audience more information. It doesn’t necessarily have to occupy the “lower third” of the screen, but that’s where it gets its name. They might seem trivial, but their necessity is clear when they’re used poorly or missing altogether which can confuse the audience.

When might be a good time to use lower thirds? If you’re filming a documentary, or any other interview-type program, keeping track of all of the subjects can get confusing without lower thirds.

If the show, company, or film has a certain tone or aesthetic, it’s good to keep the lower third design “on brand.” All of the elements of the lower third should work together to add to the visuals, not distract from them.

ELEMENTS OF A LOWER THIRD:

Color

Typography

Animation Style

Size and Position

Shapes and Logos

Setting things up

Before having an logo its better to have a few seconds of the main subject visible as to direct the viewer to all the content of the screen and after than we can introduce the company logo and typographic in a motion graphics kind of animation to make the appeal for the broadcasting network.

Title safe and Action Safe

Title safe and action safe are used to ensure that text and important visual elements in a video are clearly visible and not cut off when displayed on different screens.

Title safe refers to an area within the video frame where text or important subtitles should be placed to ensure they are fully visible on all screens, even if the edges of the video are cropped.

Action safe is a slightly larger area within the frame where the most essential visual elements should be placed, such as characters or important objects, to prevent them from being cut off on some screens.

By using title safe and action safe guidelines, video editors and designers can ensure that their content is displayed accurately and effectively on various devices and platforms.

Grid

The grid node can be used as a stensil to align the graphics on the screen and also make it look more appealing in proportions since humans can easily view imperfections.

Creating the Graphic elements

Element 1

We can use a constant and make a roto like a rectangle and transform and animate across the screen.

Element 2

For the second element we create a gradient which appears in a wipe effect in the screen, we can do this with a ramp node and creating a roto which animates over time.

We can add additional elements like transformation animation and we can make use of the curve editor to get ease in or ease out effect, which makes the whole graphic interesting.

Element 3

Here we are going to have a small box which is going to contain the logo of the broadcasting network.

first we take a constant and apply ramp which has alpha and we use the noise along with the distort node in tandum with the alpha from the gradient to get the texture and finally merge everything together.

Element 4

We do the same kind of effects for the other elements as well

Element 5, 6 and 7

Special Effects

We can create a cool special effects which looks like a box blur and slide the animation across the time to give a revealing effect to the graphic. we can use a combination of blur, grade and edge detect nodes to get this effect.

Typographics

The text part is as important as the graphics even more so, to make the text more appealing we can animate the wipe for revealing similar to the other elements of the scene, can also add drop shadow to make it more pop out.

NoOp Node

This is a useful node which does nothing, and we can use this as custom master controls which affects all the other nodes through connected link, for example we can control multiple dissolve with multiple values in the same node without the hassle to navigate through the node network.

Particles in nuke can be used to make cool effects to simulations like rain or fire ember, this is very useful in the late post production stages when it involves simple elements which does not require FX department.

• There are lots of possibility in particles and Nuke provides some presents for start-up and all of them can be modified through attributes like wind, turbulence etc.

• We can use the card as the particle emitter and we can manipulate the position of the card to change the emission as well, the bigger the card the bigger the emission surface

• By default the particles outputs Alpha value

• We can use a texture as a point colour while emitting the particles.
• The image itself cam be used as a particle and when doing this it’s advisable to use the extremely low res images since using full quality image could use all the GPU RAM.
• We can also use multiple images as particles and also 3D objects as the particles as well, and we can also animate 3D object which will apply into the instanced particles as well.
• When using 3D object it is advisable to use low poly objects.

• There are particle properties nodes like drag, gravity and turbulence, we can use these to create cool effects.

• The particles by default generates Z depth data, we can use this to create camera defocus in nuke.

• The particle emitter can also be of a geometry type.

Creating embers for fire with Particle system

• First we use a grid as an emitter geo and we rotate it in random direction to get variation in the emmission of the particles.
• Then we use various forces like wind, drag and turbulent noise to make the particles act more organic and on the specification of a real-life fire ember.
• And finally to get a visual we place a camera and a scanline render node to render the image in the viewport.
• To make the particle disappear we create a particle curve node to animate the alpha based on the age.
• To make the particles more believable we use the embedded z_depth pass into the defocus node.
• Change the colour of the particle to orange with grade.
• And if there is an movement in the plate we track and apply the transform accordingly.
• Create a base glow of the ember and create mask of that confining withing the core of the fireplace so that the centre region fire embers looks intense.
• Add that soft glow which we created into the plate.
• Create a separate glow of particle and mask the centre again and grade with extra intensity and merge the resultant image into the BG plate.

• Now to create a fake smoke field we create a noise using the FractalBlur node and tweak the parameters and shuffle out the green and blue channels and use the green channel as the alpha channel aswell.
• Animate the noise across the screen.
• Now blur extremely the embers which we created earlier and copy the alpha from the fractalblur to the blured immage and premult to get the result.
• And finally merge it to the plate.

Grain

Its important to check the grains, as it will affect the final output of the image and can be picked up in QC

regions especially cleaned up elements has tell tale signs of manipulation while doing QC, so its important to take care of those specific regions and fix grain in them.

Patch Changing Lighting

Wrong method

• Patching the tracked with the clone stamp approach will look fine if the image is stationary but we will face lighting problems if the object changes position.

CC By hand

• This is also an improper way to work since we hand animate the CC values between frames and this consumes a lot of time on production.
• Also if the light changes drastically like a red or green tint suddenly the workload increases tremendously.

Slice Tool

• We can use this to monitor the color values on an selected positions of length in the screen.

Frequency seperation patching

• We can seperate the image based on Hi and low Frequency which means hi freq is going to be the little details like edges and wrinkles and pores and the low frequency is going to be the general average lighting of the image.
• Blur the image to get the low freq and for high freq merge in blur with “from” operation to the original plate.
• So what we are doing is we paint the high frequency like clone stamp this will transfer the details to the area and we copy the same to the low freq this will transfer the light data to the high freq clone thus blending it seamlessly.

Paint work divide / multiply

Interactive Light Patch

Light / Glow matching

• Sometimes an bright source can create a haze or glow on the lens, this will washout the elements around it, so when comping our elements would look out of place, to tackle this we use curve tool and analyze the light source and apply that data to a grade to change the result.

Roto and Transform

• An easy way to remove trackers or cleanup a plate is using track, roto and transform. its basically clone stamp tool but its now tracked.

UV map / ST map

In Nuke, STmap stands for Spatio-Temporal Map. It is a node that allows you to warp and distort an image based on a reference image or sequence of images. This can be used for effects such as morphing between two images, creating fluid simulations, or stabilizing shaky footage. The STmap node is commonly used in visual effects and compositing to create complex image distortions and transformations.

The Expression:

Red Channel:

(x + .5) / width

Green Channel:

(y + .5) / height

Adv. mask removal | Colne and vectors

• Denoise the plate using a smart vector node if you have a good GPU and write it to the disk. The output may appear as a black screen, so change the AOV to smart vector.
• Adjust the vector detail based on the shot’s needs. Higher detail results in slower processing time. Lower detail can be used for shots with less detail. Write the adjusted detail to disk, as this node can slow down the script.
• Pick a specific frame, roto paint the markers, blur to avoid crisp edges, and frame hold.
• Use a vector distort node (in wraped src mode) to carry this information to other frames by plugging in the smart vector to the painted frame.
• Use a vectorToMotion node to convert the smart vector to motion vector to apply motion blur.
• Regrain from the original footage and premult to finish the process.

Adv. mask removal | Colne and vectors | method 2

• Another method of the above is to use STMap, we use this because it is very faster.

Adv. mask removal | Colne and vectors | Invert STMap | method 3

• Through this method we can stabalize an whole image and apply corrections and reverse it to track through the surface

Adding or removing details from plate

• We can add or remove textures in a plate with STmap