Blender

Blender contains a:

• 3D Modeler, and a
• Video Sequence Editor (VSE)

3D models can be used in three applications:

1. fabricating and manufacturing
2. video games
3. animation for film and video

This later use requires video editing, and therefore, the Video Editing capabilities were added into Blender, and integrated with the 3D modeling.

The blend file is a database.

It contains objects and scenes and collections.

Each object is referenced into one or more collections.

Each scene has a collection.

The user can also create collections for his own organizational purposes.

Collections can be named, colored, and nested hierarchically.

A collection can be appended or linked from another blend file.

The Blender window is divided into three parts:

1. Topbar - one line at the top containing menus.
2. Current Workspace - the large space between the Topbar and the Status Bar.
3. Status Bar - one line at the bottom containing status info.

The Status Bar is optional. It can be turned off via the Window menu.

Keyboard shortcut cheatsheet: https://drive.google.com/drive/folders/0ByidsAQcVcUUei0wc1lpVWlfUFU

The Topbar contains four menus.

1. main menu - App, File, Edit, Render, Window, Help
2. workspace tabs - one tab for each open workspace and a plus-sign Add Workspace button.
3. Scene menu - a drop-down menu of scenes, plus New and Delete buttons
4. View Layer menu - a drop-down menu of view layers, plus New and Delete buttons

There is always at least one workspace tab, one Scene, and one View Layer.

workspace, area, editor, panel, tab

A workspace occupies the window space between the Topbar and the Status Bar.

A workspace is divided into one or more rectangular areas.

Each area contains one editor.

Some editors contain one or more panels.

Groups of panels can be toggled into view via tabs.

There is always one current workspace visible. Choose among the open workspaces by clicking on its tab in the Topbar.

A default workspace is a named layout of areas. There are 22 default workspaces divided into 5 categories. Nine of these are open by default when you start Blender.

To close a workspace, right-click on its tab and select Delete.

To open a workspace, click on the Add Workspace (plus-sign) button in the Topbar, and then choose from among the default workspaces listed in the menu.

[Note: When Blender says add and delete workspace, they really mean open or close.]

To create a custom workspace, right-click on any tab and select Duplicate. Then double-click the new tab and rename it.

A custom workspace is saved in the blend file. To make it globally available, click File - Defaults - Save Startup File. This will create a startup.blend file in a new folder named for the workspace in the user's config.

./config/blender/2.82/config/Video_Editing/startup.blend

An area is a rectangular area of the workspace.

Areas are tiled, not overlapping.

Create a new area by splitting an existing area.

• Move the mouse to a corner until you see the plus sign cursor.
• Now drag the corner to split the window.

Delete an area by joining it to an adjacent window.

• Move the mouse to the divider between the areas until you see the double arrow cursor.
• Right click. The two areas become selectable.
• Click on the one you want to keep.

Each area contains one editor.

An editor is of an Editor Type. There are some 20 editor types grouped into 4 categories.

The top left corner of each area contains an icon button to drop down a menu of Editor Types. Use this menu to change the editor shown in the area. Notice that the icon identifies the editor type.

A panel is a rectangular area within an editor.

A panel can be collapsed or expanded.

A panel can grabbed and dragged to reorder the panels.

A panel can have sub-panels. For example, in the Properties editor, in the Output panel, a different set of sub-panels is shown depending on your setting of File Format.

Some editors contain a side panel on the right that can be toggled into view by clicking n. [Example: Video Sequencer.]

Tabs are sometimes used to switch among multiple sets of panels.

Tabs can be on the left, the right, or above the panel viewing area.

[Example. See the Properties Editor.]

Startup File - default file with layouts, settings, and preferences

• File - Defaults - Save Startup File
• File - Defaults - Load Factory Settings

Preferences

• Edit - Preferences - menu - Save Preferences (saves preferences only to the startup file)
• Edit - Preferences - menu - Load Factory Preferences

The Preferences are a subset of the data in the startup file and can be saved and reloaded separately.

YouTube: The CG Essentials: Creating and Saving CUSTOM WORKSPACES in Blender!

Edit - Preferences - Interface - Python Tooltips: check on

areas (Editor Type - Scripting):

• Text Editor - write python scripts here. Save and open files. Alt-P to run script.
• Info - history of python commands executed by the UI.
• Python Console - interactive python console. import bpy has been at done automatically.

System Console Window - Errors from python scripts run in the Text Editor display in the System Console Window, not in the Python Console. In Linux, start blender from the command line. The terminal window is the System Console Window. If you close the terminal window, Blender stops immediately without saving.

YouTube: Curtis Holt: Python Crash Course for Blender!

Blender's command-line options allow you to execute a pipeline of digital video processing and rendering on any number of files in a background, GUI-less process.

Example: 
    blender <filename.blend> -b -P <scriptname.py>

where:
-b 
      Run in background, no UI.

-P  <scriptname> 
      Auto-run the named python script.

Blender Manual: Command-Line Options

YouTube: Blender Guru: Blender Beginner Tutorial Part 1

model - A collection of objects built within the world.

world vs object

• 3D objects exist within the 3D world.
• There is one world, and multiple objects within that world.
• Objects are made of vertices, organized into edges and faces.
• A selection may refer to objects, vertices, edges or faces.

navigation vs transformation

• navigation applies to the world, or rather, to my view into the world
• transformation applies to an object or a selection
• both navigation and transformation occur along or around an axis
• there are three axes: x,y,z
• navigation does not change the world. It only changes my view into that world.
• transformation actually changes the model.

3D Viewport - The editor type we use to do 3D modeling. Provides your view into the world. 3D Viewport

gizmo - a UI device that allows navigation or transformation with the mouse. A gizmo always has three color-coded axes: X (red), Y (green), and Z (blue). Gizmo

• Navigation Gizmo - applies to the world. Found in upper-right of viewport.
• Transformation Gizmo - applies to object or selection. Appears at the pivot point, aligned with the transform orientation.

pivot point -

• for one object, or for a selection of objects, or in edit mode for a group of selected vertices
• determines the locaion of the “object gizmo”, and thus is the center of transformations
• types:
  • bounding box center
  • median point
  • center of mass
  • center of geometry

normal - the line perpendicular to a face.

origin -

• world origin - the point at world coordinates 0,0,0. Constant.
• local origin - average center of all selected objects of vertices.
• object origin - local origin of a single selected object. By default is the bounding box center of the object. Can be moved by setting it to the 3D cursor.

3D Cursor - a singleton object with location and rotation. By default it is at the world origin. Set it using the toolbar or the Snap menu via left-click or shift-S. The 3D Cursor has multiple purposes. It defines where newly added objects are placed. It can be used to manually position and orient the transform gizmo.

transform orientation - the orientation of the Object Gizmo. Can be selected from the 3D Viewport Header menu.

• global - aligned with the world space
• local - aligned with the active object's orientation
• normal - fancy. normally equivalent to local.
• gimbal - fancy. Involving Euler math.
• view - aligned with your viewpoint as you orbit.
• cursor - aligned with the 3D cursor.
• parent - aligned with the parent.

rotation mode - fancy. involving Euler math.

Note: object origin vs pivot point vs transform gizmo

• A transformation requires a pivot point and a transform orientation.
• if a single object is selected, the pivot point is the object origin. The object origin is by default the bounding box center, but it can be moved using the 3D cursor.
• If multiple objects or vertices are selected, the pivot point is at the average point of the selected objects.
• The transform orientation can be selected on the 3D viewport header, see above.
• The transform gizmo visualizes the pivot point and the transform orientation.

Views:

• orthographic (flat): top, bottom, front, back, right, or left.
• perspective (having depth)

To switch views:

• press tilde ~ and choose a menu option
• for hotkeys, set Preferences - Input - Emulate numpad.

To navigate:

• use Navigation Gizmo, in upper-right corner, plus magnifying glass and hand.
• drag mmb to orbit. View automatically switches to perspective.
• shift-drag mmb to pan.
• scroll wheel, zoom view in and out
• use Object Mode - View menu: pan, orbit, roll, zoom

t toolbar on the left, toggle on and off
buttons to move, rotate, scale, all three

put mouse into a mode

• g grab
• r rotate
• s scale

confine movement to an axis

• x, y, z
• click mmb

add an object

• duplicate
• shift a, add, add - mesh - primitives menu: cube, plane, cone, monkey, torus

shift+A: add an object primitive

Cycles - slow, ray-traced, unbiased, for high-end movies

Eevee - fast, for real-time games

Particles move.

Force fields affect the movement of particles.

For a particle to move in space, it must simultaneously move in time, hence particle movement is done through animation.

Particles are by nature animated.

Force fields affect the movement of particles.

Force fields can be experienced only in the presence of particles.

Particles can be experienced only in the presence of a force field.

Empty Object

• can enable physics properties
• cannot add particle emitter modifier
• choice of visual representation

Force Field

• no choice of visual representation, given by type of field

object properties

• transform
• relations
• collections
• instancing
• motion paths
• visibility
• viewport display
• custom properties

add “effector”, ie “field”

add “empty”

choices at add time

• type
• radius
• align
• location x,y,z
• rotation x,y,z

types

• empty, type of visual representation
• force field, aka field, aka effector, type of force

How to group multiple objects into a subassembly:

• Collection
• Collection Instance
• Parenting
• Boolean Un1on (NOT for subassembly)

There are two ways to use a collection.

1. Use it to organize the hierarchy in the outliner.
2. Use it as a class that can be instantiated multiple times.

You can hide/unhide the whole collection with one click.
But you cannot move/rotate/animate the collection as a unit.

Every collection can be instantiated.
The instance appears as a single line in the outliner, and is treated as a single object.

How to:

• Build a collection someplace - separate file, separate scene, separate hidden area of outliner.
• Add an instance of that class to your project.
  • Add-Collection Instance-your collection. This does a link.

Not recommended: Object-Apply-Make Instances Real. This copies all the component objects flatly, not organized.

How to:

• Select two or more objects in the outliner.
• One of the objects will be “selected”, the others merely highlighted.
  • Shift-click leaves first object clicked as selected.
  • Cntrl-click leaves last object clicked as selected.
• Object-Parent-Object. Makes selected object the parent; moves the others under it in the outliner.
• Recommended: Add empty object to be the parent.

You can move/rotate/animate the group as a unit.
But you still have to hide/unhide components individually.

Use for sculpting a single component.
NOT appropriate for a subassembly.

How to:

• select object to modify.
• Wrench - Add Modifier - Boolean - Un1on
• second object: a copy of this is merged into the selected object
• hide the second object to see the results
• Apply - this makes the modification permanent.

The selected object is modified. Its mesh is altered.
The second object is unaffected and may now be deleted.

Usage recommendations:

1. For a unique, one-off subassembly, use an empty parent within a collection. Use the collection to hide/unhide; use the empty parent to move/rotate/animate.
2. For a subassembly replicated multiple times, build a collection as a class, kept in a normally hidden collection of the outliner hierarchy, and add multiple instances into the final assembly.
3. For a component that will be 3D printed, keep it a separate simple object without modifiers or materials, so that it can be exported to a separate .STL file.

Solve problems with audio-video sync.

• https://www.youtube.com/watch?v=n7qeKekS10E
• In this video, Mikeycal Myers explains importing videos from a smart phone.
• Changing the fps from variable to constant 24 using Handbrake.
• If there is an extra frame on the audio track, use Hold-Offset-End property to bring it back.

scroll and zoom video sequencer (squeeze height of channels)

• set user preferences input to emulate middle mouse button, using alt by default.
• alt left drag to scroll sequencer up, down, right, left
• ctrl alt left drag to zoom sequencer up, down (height), right, left (width)

Timeline

• mousewheel: zoom in and out horizontally
• shft-mousewheel: pan timeline up and down
• ctrl-mousewheel: pan timeline left and right
• MMB drag: pan timeline left, right, up, down
• ctrl-MMB drag: zoom timeline, horizontal and vertical

Playhead

• alt-mousewheel: move (scrub) playhead forward and back
• VCR controls: jump to start, jump to end, play forward, play backward, pause

move strips around the timeline

select strips, hover mouse over timeline window, click g to grab, click x or y to constrain, drag with mouse

keep video and audio together

select both and click ctrl-G to make a metastrip

click tab to toggle into and out of metastrip view

click shft-L to lock a strip. shft-alt-L to unlock

From camera to Blender?

1. Shoot video with camera phone.
2. Copy to video work folder, using SSHelper and SCP.
   1. scp -r -P 2222 '192.168.1.100:/storage/emulated/0/DCIM/Camera/VID*.mp4' .
3. Open each video clip in Handbrake.:
   1. Change the output folder.
   2. Goto video tab and change settings
      1. Framerate: 24
      2. Constant Framerate
   3. Start, save.
4. In Blender, drag clip to timeline.
5. Compare audio to video. If audio length is one frame longer:
   1. Click on the audio track
   2. goto property panel
   3. click the Time dropdown
   4. property Hold Offset End, increase from 0 to 1
   5. The two tracks should now match
6. set end, three ways:
   1. Timeline, View, Range, Set Frame Range to Strips
   2. set explicitly to 10000
   3. position blue line at one frame before the end, and click Ctrl-End
7. repeat above steps for each clip
8. crop each clip
   1. position the playhead, select the tracks, click k to cut
   2. select the unwanted pieces and click delete (Yes)
   3. select the strips to move, click G to grab, then X to constrain to X axis
   4. drag the strips to the right until the border turns red, then click to drop into next frame

YouTube: Ryan King Art: How to Green Screen with Blender

YouTube: CG Cookie: Learn Green Screen Basics with Blender

make two blender files, one with Video Editing, one with Compositor

1. Framing the talking head.
   1. Divide the screen into thirds.
   2. Eyes should be just above the top horizontal line.
   3. Leave two fingers of space above the head.
   4. Shoot with horizontal center.
   5. Later when editing with background graphics, if you shift the head to the left,
   6. center the head on the left vertical line.
   7. Keep camera at eye level.
   8. Keep head 20 cm in front of the green screen to minimize shadows around the head.
2. Use handbrake to sync audio and video framerates.
   1. Framerate 24
   2. Constant Framerate
   3. To: project folder
   4. Optional, specify range for a sample file.
   5. Start
3. Make blender project to filter green screen.
   1. New General Compositing.
   2. Check Use Nodes.
   3. Delete the Render Layers node. Keep the Composite Node.
   4. Shft-A to add a node, Input - Movie Clip. Open: select the handbrake output.
   5. Add node, Output - Viewer.
   6. Draw a line connecting Movie Clip Image to Viewer Image.
   7. Click Backdrop to see Viewer Image in compositor window behind the nodes.
   8. Add node, Matte - Keying.
      1. Drop it onto the line between Movie Clip and Viewer.
      2. Choose Key Color with eye dropper.
   9. Draw a line from Keying Image to Composite Image.
4. Render the Composite Node.
5. New Blender project for VSE.
   1. Find output frames folder rendered in previous step.

Pan and zoom head using Effect Strip, Transform, and Keyframes https://www.youtube.com/watch?v=hFVPXTO7px8

Fade in

1. Select a strip
2. position counter to first frame
3. in properties panel: Adjust - Compositing
4. change opacity to 0
5. with cursor over the value, click i to create a keyframe
6. reposition counter to frame 24
7. change opacity to 1 and make keyframe
8. do the same for Adjust - Sound - Volume
9. use a Graph Editor window to edit the keyframes
10. YouTube: Ryan King Art: Video Editing Part 3

keyframe color codes

• gray: normal
• yellow: on a keyframe
• green: between keyframes

right-click on any value in the property panel to bring up the keyframes context menu

1. Make presentation slide show in LibreOffice Impress or Google Slides.
2. Export as PDF.
3. Use ImageMagick to convert pdf to multiple PNGs.
   1. convert
4. First time, ease policy restrictions in ImageMagick.
   1. Edit the file in etc named ImageMagick-6/policy.xml
   2. Comment out the line containing “PDF”

In Blender, separate the video and audio strips.

1. Create a new project, open the video with a voiceover.
2. Render - Render Audio…
3. Select format mp3, enter output filename, click OK.

In Audacity, open the new audio file.

1. Noise Reduction
2. Equalizer
3. Compressor
   1. Threshold: 12 or 30
   2. Noise floor: 50
   3. Ratio: 3 to 1
   4. Attack and release: minimum
4. Normalize (aka Amplify)

https://www.youtube.com/watch?v=dQCB72S64L4
https://www.youtube.com/watch?v=TYF5ytMDFpA
https://www.youtube.com/watch?v=twlY29iX1dU

• mp4 - original shoot from camera phones, with variable framerate
• m4v - from Handbrake, with constant framerate of 24 fps
• mkv - clips captured in OBS Studio
• mp3 - audio track separated out by Blender Mixdown, input and output to Audacity
• jpg, jpeg - stills, no alpha channel
• png - stills with alpha channel possible
• frames/*.png - individual frames rendered by Blender compositor render after green screen filtering
• odt - script document from LibreOffice Writer
• odp - slideshow presentation from LibreOffice Impress
• slides/*.png - individual frames from slideshow, output by ImageMagick from PDF

Preferences

• Interface
  • Python Tooltips: checked
  • Resolution Scale: 1.30

Remove File Browser

Two Video Sequencers

• one in sequencer view
  • View - Waveform Display: On
• one in preview view
  • right click in top menu bar
  • show header: not checked

Properties

• Dimensions - Resolution: 1920 x 1080
• Dimensions - Frame Rate: 24
• Output - destination folder name
• Output - File Format: PNG or FFmpeg
• Output - Encoding - Video: H.264, medium quality, good speed
• Output - Encoding - Audio: MP3 for youtube, AAC for mac/iphone
• Color Management - View Transform: Standard (Filmic for 3D model rendering)

Timeline

• Playback - Sync: AVSync (No Sync for simulations)
• Playback - Audio Scrubbing: checked

YouTube: Ryan Art King: Video Editing with Blender! Part 1

Combine 3D Model, Python, Timeline, Sequencer.

In the Layout editor, choose a camera view.

In the Scene menu, do a Full Copy to create a second scene. (You cannot add the current scene to the Sequencer. You can only add other non-current scenes.)

In the Sequencer, Add - Scene - select the scene.

YouTube: Adding 3d scene into video sequencer

You are working in the video sequencer, but
the drawing animation must be done in the modeling view.
Therefore three steps are required.

1. In the video sequencer:
   1. Select your desired section of video.
   2. Render an image sequence of that section.
2. In the modeling view:
   1. Add the image sequence from step 1 into the layout or modeling view.
   2. Draw over the video. There are at least two ways to do the drawing.
      1. the grease pencil
         • can be drawn by hand
         • must be animated keyframe-to-keyframe by hand
         • YouTube: jimmy something doodles: How to draw over videos
      2. the bezier curve
         • cannot draw by hand, must manipulate the curve
         • can be animated automatically from one end of the curve to the other
         • YouTube: Blender Made Easy: Easy Handwriting Animation
   3. Render the animation as a movie.
3. Back in the video sequencer:
   • Add the movie output from step 2

Today is 10 Oct 2021.

• My current blender version is 2.82.
• sudo apt search blender returns blender 2.82
• blender.org says the latest version is 2.93

If I want to move to 2.93,
I think I have to uninstall my current version
and then install the new version by downloading from blender.org.

The user's linux config folder contains these files:

• userpref.blend
• startup.blend - default startup blend file
• Video_Editing/startup.blend - created when you save a startup file

In the github sandbox project, folder blender, find these example blend files:

• proto.blend - start with this for video editing per Ryan King video
• magetic.blend - demo particle system
• curtis_holt.blend - companion to video Python Crash Course for Blender
• donut.blend - companion to 3D modeling tutorial by Blender Guru

Directory structure for a blender project folder:

• projectname
  • clips
  • stills
  • host
  • slides