“TERM TWO – JANUARY“
WEEK 17
Green Screen (Contd.):
- The despillmadness gizmo is a downloadable gizmo. (bm_Despill – Keyer – Gizmos – Nukepedia)
- Playing with channels is not frequently used.
- Always structure your key into 3 pipes:
- Alpha / matte pipe
- Color /despill matte
- Bg Plate
- Always breakdown alphas by creating a core matte and an edge/hair matte.
- Remember to denoise and white balance plate before key (f necessary even out green screen
- Also, Despill should be addressed separately for core and edges (lighter core and stronger edger)
- In the despill phase you can manipulate the edge despill to match bg colors.
- Use Neat Video – best noise reduction for digital video website for denoising the plate.
- But side effect of this is the plate becomes really soft.
- The EdgeExtend node softens the edges of the subject after removing the green screen bg. It extends the edges to remove spills, i.e., it extrudes the rgba edges to extract information from the subject.
- For footages without an even green screen bg, it is better to not directly add keylight node, but to add color channels and then evening out the green screen before adding the keylight node.
- IBK Stacked helps in a more clearer alpha.
- Lightwrap node introduces light from the background to the foreground and outlines the subject to blend the subject to the background.
Green Screen Tips:
- ADDITIVE KEY is not an actual keyer, but it is an image blending technique used to recover fine detail in difficult areas such as wispy hair, soft transparencies and motion blur If combined with a good matte, edge treatment and despill can create very good results to better integrate your plate to the bg.
- Additive Key manipulates lightness values in the fine details and ADDS it to the bg under the foreground plate.
IBK Stacked
Look into Mail – Mahadev Vipin – Outlook (office.com) For reference. [greenscreenV05] and [greenscreen_tips_v06]
WEEK 16
Luminance:
- HSV Color Scale: The HSV (which stands for Hue Saturation Value) scale provides a numerical readout of your image that corresponds to the color names contained therein. Hue is measured in degrees from 0 to 360.
- Can change color channel from linear to HSV.
- R = Hue: Hue literally means color.
- G = Saturation: It pertains to the amount of white light.
- B = Luminance: It is a measure to describe the perceived color brightness.
- huecorrect node is use for hue corrections by muting or cutting down colors from a footage.
- There are 3 methods for huecorrection :
- Muted
- Supress (_sup)
- Desaturated (sat)
- Don’t work with QuickTime. Convert files to exr before working on it.
- The keyer node helps to distinguish between alpha channels of the footage, i.e., You can see alpha channels of footage that basically has no alpha.
- Can control the keyer using the yellow bars in the props tab.
- There are several options under the keyer node:
- Red keyer
- Blue keyer
- Green keyer
- Redscreen
- Bluescreen
- Greenscreen
- Luminance key
- Saturation key
- Max keyer
- Min keyer
- Add Reformat node if necessary > Keyer node > Grade the reformat node and the mask it to the keyer node.
- YPbPr is the analog video signal carried by component video cable in consumer electronics. The green cable carries Y, the blue cable carries PB and the red cable carries PR.
- Alpha channel value has to be between 1 and 0.
- volumeray node is used for illusion of light rays. It is a very heavy node.
- Create a new channel output:
- Roto > Draw curves > In the output section of Props tab, create a new one > Grade node > Enable mask > Select the new output name.
- Denoise the plate before doing all the color channel corrections.
Green Screen:
- Types of keys:
- 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. (IBKGizmo and IBKColour)
- We can use the IBKColour node to create a clean plate from the footage by tweaking the values of Erode, Size, Darks and then finally maxing the value of Patch Black to see the clean plate.
- We can use the IBKGizmo to see the footage after clearing out the green screen.
- 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.
- Always enable the USE GPU IF AVAILABLE.
- Keylight is a really great keyer overall and does color spill. Works much similar to that of aftereffects. Can tweak with screen matte options like clip black, clip wite, etc to check out the footage after removing green screen and alpha channel. It gives an automatic despill of green screen.
- 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. It also enables an option called auto compute. Mainly used for motion blurs, etc.
- Ultimatte is a phenomenal key that can get really fine detail and pull shadows and transparency from the same image.
- 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. (IBKGizmo and IBKColour)
- After Effects natively uses 8-bit but Nuke uses 16-bit image processing. A 16-bit image will let you do more extreme editing before losing quality and details.
- Select the area of green screen using Alt+Aclick and drag.
Look into Mail – Mahadev Vipin – Outlook (office.com) For reference. [greenscreenV05]
WEEK 15
Passes:
- Continuation of last week
- Example 1: Unpremult (all) > Merge > Specular > Grade > Merge > Remove > Premult
- Example 2: Unpremult (all) > Merge > Indirect diffuse > Grade > Merge > Remove > Premult
Relighting:
- Different materials can produce different results. eg: Phong, Diffuse, Specular, etc.
- Change point size for bigger or smaller points in Properties tab.
- Custom nodes are called Gizmos.
- The Gizmos are free but if you are working for company, beware of copywrite infringement. Always ask before using downloaded gizmos.
- You can create custom node by copying the node fully from Nuke and pasting it on Notepad, word, Gmail or anything.
- Select node codes from Notepad, copy and paste it onto Nuke, that’s it to create your own node.
WEEK 14
Types of projection:
- Patch projection
- Coverage projection
- Nested projection
- Use Alembic, fbx formats. Never use older formats like obj, glb, etc.
Projection Artefacts:
- Smearing: An image smearing or striking across the glancing angle of the object.
- Doubling: When a matte painting projects onto a multiple geometry
- Resolution: Not enough resolution in the painting because of the camera getting too close
ModelBuilder:
- Available in NukeX versions
- Add Cards to replicate 3d buildings or models.
- Can add Bevels, Extrude options like 3D in Maya.
- Use Bake option for finally replicating the 3D environment.
Pre-comp:
- The Precomp node is like a group node, but its content is stored in an independent .nk file.
- They can be used to reduce portions of the node tree to pre-rendered image inputs. This speeds up render time, as Nuke only has to process the single image input instead of all the nodes that were used to create it.
- Because the original nodes are saved in a separate .nk script, you also maintain access to them and can adjust them later if necessary.
- They enable a collaborative workflow. While one artist works on the main comp, others can work on the sections that have been exported using the Precomp node. These sections can be edited, versioned, and managed independent of the main comp.
CG:
Arnold Multipass Comp
- Render Passes or AOVs (Arbitrary Output Variable)
- Render passes offer you a way to control any aspect of a scene that is, in-turn used to automatically produce multiple rendered images. Each rendered image reflects all the settings of an individual pass. In their most basic sense, Render Passes are simply containers for channel values. Once you add a pass, subsequent edits to the scene are stored within the current pass or passes.
- Beauty rebuild passes:
- Material AOVs
- LightGroups
- Data Passes:
- Utilities
- IDs
Different Render Engine:
“TERM ONE – OCTOBER to DECEMBER“
End of Term One
WEEK 11
Real scenarios in Production:
- Review your work no matter how much time left. It is really important to check for problems however minute they might be before rendering and submitting the work.
- Publish your work into the project, i.e., you have a version you would like to be reviewed by VFX supervisor or producer.
- Tech check before publishing a version.
- Stages in Production for film in compositing:
- Temps/ Postviz – (Postviz sequences give post-production artists a much clearer understanding of the director’s intent and provide VFX teams with digital assets that can be used simply as reference or upgraded directly for use in the final imagery.)
- Trailers
- Finals
- QC – Quality Control / Check
- VFX Production Roles:
- VFX Line Producer – central to the VFX project management.
- VFX Producer – ensures the studio to complete projects on time, within budget and to high standards. Even I can become this. No restrictions.
- VFX Dailies:
- A meeting that happens often each morning when the artists working on a project meet-up to share their work in its current state.
- The purpose is to make sure they are moving in the right direction and to get feedback from the director, client, producer or supervisor.
- Desk Dailies Review:
- Lead Comp
- Line producer
- VFX Producer
- VFX Supervisor
- Small Cinema Dailies:
- Line Producer
- VFX Producer
- Lead CG
- Lead Comp
- VFX Supervisor
- Big Cinema Dailies:
- Lead CG
- Lead Comp
- Line Producer
- VFX Producer
- VFX Supervisor
- Editorial
- Lighting Lead
- Client Producer
- Client VFX Supervisor
- Client Director
- TRUST is the biggest word in the industry.
- Don’t share any pictures, videos, news about a project with anyone. Because IT IS A BIG RED FLAG in the industry. Non-Disclosure Agreement (an agreement you will sign before joining a project) will be broken along with trust, may lose job and engage in lawsuits or legal battles.
WEEK 10
- To save workspaces select Windows > Save Workspace
- To open the saved workspaces, go to Workspace and then you’ll see the saved workspace.
DasGrain:
- Does not necessarily require NukeX. Works in any Nuke.
- DasGrain, by Fabian Holtz, is a semi-automatic regrain tool which intelligently analyses the grain in your plate, and uses it to regrain an entire degrained comp.
- It works by:
- Isolating the grain by finding the difference between a plate & its degrained counterpart.
- Analyses the grain response over a range of luminance and adapts the grain to fit your comp based on its own luminance.
- Uses a mask input to restore the plate’s original grain, so you don’t have to Keymix your plate back over top at the end of your script.
Match move:
- Match-moving is the opposite of stabilization.
- The intent is to record and use the motion in an image and apply it to another element.
3D System:
- NukeX 14 and above allows 3D beta versions. Lower versions only enable the use of classic 3D nodes.
- DON’T WORK in FBX, Work in Alembic.
- Scanline Render: Every Scene node in a script should be connected to a ScanlineRender node, which tells Nuke to render the results of the scene. The ScanlineRender node also allows you to toggle between a 2D and 3D view of the scene.
Lens Distortion:
- A lens is a series of curved pieces of glass that bend light and focus the rays on the image plan.
- Some lenses have low amount of distortion and won’t affect a track too badly, but a wider lens have more severe bending of light.
- To check that, look for straight lines like walls. They will appear to be bended.
- LensDistortion node (Undistort/Redistort). Only available in NukeX.
- It reads the horizontal and vertical lines and makes the Straight.
- The more the lines added to lens distortion, the more accurate it will be.
- The LensDistortion node is really heavy and there are more chances of crashing. STmap is an alternative node for LensDistortion.
*ASSGNMENT FOR NEXT WEEK: Finish the Balloon Festival.*
WEEK 9
Defocus:
- Defocus emulates the way an out-of-focus image would look through a lens, while Blur simply blurs the image or matte.
- If you want an out-of-focus image, then use a DEFOCUS instead of Blur because it looks more realistic.
Depth Channel:
- When viewing the depth channel in Nuke, it might only show red. The Depth channel will give you non-anti aliased, non-normalized depth data in the alpha channel.
Z-Defocus:
- Z is just Depth
- Depth channel can be changed in properties tab after selecting ZDefocus node.
- At the moment, don’t change or focus on math.
- Can change the depth using focal point section in properties tab.
- Wrap Defocus – Shifting the focus between two different objects/subjects in a frame.
- There are several output modes in Properties tab:
- Focal plane setup (The green color area will have sharper focus)
- Layer setup (makes layers to smooth out focus between something close and then far away) (the more value the smoother and more precise)
- Filter shape setup
- Result
Bokeh Builder:
- Bokeh defocuses an image according to a Z depth map, Deep data, or Camera information and allows you to control where the focal plane lies so you can focus on specific elements in an image and simulate real-world lenses.
- Bokeh Builder has been created as part of a smaller lens simulation project and needing to be able to create varied bokeh shapes easily and quickly.
- With options controlling noise, glass artifacts, overall shape, ring compression and various other features found in real life bokeh, this gizmo can be used to easily create interesting shapes to drive defocusing in an artistic way.
- Only works in NukeX.
Convolve:
- Convolve lets you create custom filter effects by supplying your own filter image.
- The new value of a pixel is calculated by centering the filter image on the pixel, examining its neighbours, multiplying each pixel value by the corresponding pixel values in the filter image, and then adding the results together. This allows you to defocus a clip and create lens blur effects in the shape of the filter image, for example.
- This node is very rarely used.
- ZDefocus node is the most frequently used node for filtering and blurring image or video.
RotoPaint:
- The RotoPaint node gives more features or tools than normal Roto node.
- It is used to clean up and clone out unwanted elements from the plate.
- Keep it simple and separated. Don’t use big Beziers in roto. Divide it into parts.
- P -Shortcut for RotoPaint
- Select Ctrl to select the area to clone and then paint/clone.
- Select Shift to increase or decrease the size of the brush.
- Use WACOM pencil to clone because it provides better results than mouse. It is used extensively in the industry for perfect results.
- Increase the Hardness value to crisp the output of the clone or decrease it for smoother outputs.
To select the frames where the clones should be visible, click on that section.
To change the frames where the clones should be visible, select the clones and click on life to change it OR You can change it in the Lifetime are in the Prop tab
- You can edit the clones even after you thought you finished by selecting it in the Prop tab.
- To revert to original plate, select either Eraser tool or Reveal tool.
- You can also brush areas you want to Blur using the Blur tool in RotoPaint.
- You can also brush areas you want to Sharpen using the Sharpen tool in RotoPaint.
- You can also brush areas you want to Smear using the Smear tool in RotoPaint.
- You can also brush areas you want to Dodge using the Dodge tool in RotoPaint.
- You can also brush areas you want to Burn using the Burn tool in RotoPaint.
Grain:
- Grain matching – ensuring that all of the elements in a composite, including those which were digitally generated, look like they were shot on the same film stock – is often one of the final steps in achieving a convincing integration of all of a composite’s elements.
- Nuke offers effects for synthetically creating grain and for reading in practically created grain (grain derived from actual film stock).
- F_ReGrain is way more accurate than normal Grain node.
- F_ReGrain is only available in NukeX.
- The render speed will be decreased after using F_ReGrain node.
- F_ReGran is designed to sample an area of grain from one image and then to generate unlimited amounts of this grain with exactly the same statistics as the original. This new grain can then be applied to another image.
- Most studios use the plugin NEAT VIDEO to remove grains. But then the video loses quality and sharpness.
*ASSGNMENT FOR NEXT WEEK: Add elements to the School Room.*
WEEK 8
Filtering Algorithm:
- Image filtering algorithms exists to help us define what happens to our pixels as we transform and process the images.
- DONT GO over 10%. Max – 50% to change the format of an image.
Concatenation:
- It is the ability to perform one single mathematical calculation across several tools in the Transform family.
- Don’t add Grade, Color Correction node or any other non-concatenating nodes between two Transform nodes to avoid BLUR in the footages. It loses a lot of detail in the footage.
- Add Grade, Color Correction node or any other non-concatenating nodes before or after any Transform node.
- BBOX or Bounding Box defines the area of the frame that Nuke sees as having valid image data. The larger the bounding box is, the longer it takes Nuke to process and render the image. To minimize processing and rendering times, you can crop the bounding box. Occasionally, the bounding box may also be too small, in which case you need to expand it.
Shuffle:
- Rearrange up to 8 channels from a single image (B input). For example, you can use it to swap rgba.red for rgba.green, and vice versa.
- Rearrange channels between two separate nodes (A and B input), like a foreground and background branch.
- Replace a channel with black (removing the alpha channel, for example) or with white (making the alpha solid, for example)
- Create new channels.
- Press TAB on the Viewer to create 3D Space.
- Use CTRL key to rotate.
- Use Mouse Scroll to Zoom in/Out.
- Press Mouse Scroll to Pan Left/Right
- Select PG UP/DOWN arrows after placing mouse on the viewer to change channels.
Planar Tracker:
- Good for videos with perspective shift.
- Planar Tracking Node in Tab
- Cornerpin Absolute may shrink the image to be tracked so it’s better to use Relative because it translates the corners roto-ed perfectly and removes image deformation.
- Cornerpin Baked does not allow any adjustments to be made to the roto-ed iamge/footage.
Defocus:
- Ramp is a node that shows color channel from black to white.
- Ramp Generates a gradation between two defined edges.
- Use Defocus node instead of Blur node for a filmy look.
ASSGNMENT FOR NEXT WEEK: Get ready 2-3 textured hot air balloon 3d models, 60% of the look AND Replace the 1st and 2nd poster in the place, add a third element e.g. graffiti, drawing (should be obvious)
WEEK 7
2D Tracking:
- Transform is a super useful node that deals with translation, rotation, and scale as well as tracking, warping, and motion blur.
- The 2D tracker allows you to extract animation data from the position, rotation, and size of an image. Using expressions, you can apply the data directly to transform and match-move another element. Or you can invert the values of the data and apply them to the original element – again through expressions – to stabilize the image.
- Click Tab – Select Tracker
- Tracker node can contain 1 or more tracking points inside it. You can check by selecting the Tracker node in Properties Tab.
- Types of Tracks:
- 2D Track
- 2.5 Track (2.5D (two-and-a-half dimensional) perspective refers to gameplay or movement in a videogame or virtual reality environment that is restricted to a 2D plane with little or no access to a three dimensional in a space that otherwise appears to be three-dimensional and is often simulated and rendered in a 3D digital environment.)
- 3D Track
Always Turn this ON
“ASSIGNMENT FOR NEXT WEEK: ROTO FINGERS ON iPHONE AND ADD A MOVING WALLPAPER, & ADD COMPONENTS TO THE ROTOed MOUNTAINS LIKE HOUSE,WALLS,etc”
WEEK 6
NUKE
Premultiplication (NODE):
- TRY TO BE ORGANISED WHILE WORKING
- Premult multiplies the inputs rgb channels by its alpha, i.e., multiplies the RGB values by the alpha.
- Premultiplies the input image
- It is used for:
- Merging unpremultiplied images. This avoids unwanted artifacts, such as fringing around masked objects.
- Color correcting premultiplied images. When you color correct a premultiplied image, you should first connect an Unpremult node to the image to turn the image into an unpremultiplied one. Then, perform the color correction. Finally, add a Premult node to return the image to its original premultiplied state for Merge operations.
- Add Premult node by searching in TAB or find it Properties tab and under Output option.
- PG UP and PG DOWN for shuffling between rgb and other color layers
- M – Shortcut for Merge
- G – Grade
- T – Shortcut for Transform
- D – Disable
- Merge node in Properties tab has several operations including Over, Overlay, Divide, etc
- Crl+Shift+X – Change Background and Foreground
- Reformat node helps in resizing and repositioning image sequences to different formats (width and height).This also allows you to use plates of varying image resolution on a single script without running into issues when combining them. All scripts should include Reformat nodes after each Read node to specify, at the very least, the output resolution of the images in the script.
- You can change the image format in Properties Tab after selecting Reformat.
- Add Unpremult to an image and then Grade/other node and Again Premult to change values of grade of the main image without affecting BG image.
ColorSpace and Linearization:
- Colorspace defines how the footage was captured or exported. Most files are non-linear, and knowing the correct colorspace is critical for proper linearization.
- Linearization is the process of converting footage into linear space. All the tools inside nuke are built around linear math. This also allows the mixing of media types.
- Rec709 is a color format.
- 8 -bit colors = 256 colors
- 16-bit colors = 65536 colors
- 24-bit colors = 16.8 million colors
- Nuke uses 24-bit colors
- Import LOG files as SLog file instead of Linear.
LUTs, CDLs and Grades:
- LUTs can be used for creatively or technically, i.e. converting from log to linear, or adding a “look”.
- CDLs are creative, i.e., adding a look to the clip.
- Graded footage means color added to its final look.
- Highlights, Midtones and Shadows are important part of color correction.
- Commonly used nodes are Grade and Color Correction.
- In Nuke, to grade Highlights we use either GAIN or MULTIPLY, to grade Shadows we use LIFT and to grade Midtones we use GAMMA. In Color Correct node, Lift is called Offset.
- Color lookup is similar to the color curve in Photoshop.
- The line graph goes from 0 to 1 by adding and manipulating points we can grade the image.
- Add a point in the line – CTRL+ALT+CLICK and then remove point CTRL+X.
- Group involves 2 or more nodes.
- Can be identified with S on the properties tab.
- Has a hexagon shape instead of the normal rectangle shape for the node.
WEEK 5
NUKE
Rotoscoping:
- Rotoscoping describes the process of manually altering film footage one frame at a time.
- Roto node & RotoPaint are similar. The main difference between these two is that you can only create and edit Bezier and B-spline shapes with Roto, while RotoPaint allows you to draw paint strokes too with various brushes.
- “DIVIDE AND CONQUER”, i.e, Divide each parts before roto-ing or in other words split each sections of a body from head, arms, legs etc.
- ” LESSER THE POINTS, EASIER THE WORK”
“ASSIGNMENT FOR NEXT WEEK: ROTO THE MAN AND ROTO THE MOUNTAINS”
WEEK 4
NUKE
- Compositors create the final image of a frame, shot or VFX sequence. They take all the different digital materials used (assets), such as computer-generated (CG) images, live action footage and matte paintings, and combine them to appear as one cohesive image and shot.
- Digital Compositors Job Progression :
- Roto
- Prep
- Junior Compositor
- Mid Compositor
- Senior Compositor
- Lead Compositor or Department Head
- 2D Supervisor
- VFX Supervisor
- Different versions of NUKE :
- NUKE
- NUKE X
- NUKE STUDIO
- NUKE NON-COMMERCIAL
- NUKE STUDENT
- NUKE INDIE