CS 488 21 Nov Notes.md

30.8 Animating Camera motion

• bunch of guidelines for how to control a camera...
• often want to specify what the camera 'looking at'; then animate it along a path and let the computer ensure it looks at its target throughout the animation

30.9 Tools for Shape Animation

Skeletons

• (Armatures/Rigging in Blender)
• Give a 3d model bones/joints separate from the model (not hierarchical like puppet)
• Manipulate the (simpler) skeleton to manipulate the (complex) model
• Also useful for previewing animations without having to manipulate the complex model at every frame
• Skeleton not visible during render

Free-Form Deformations (FFD)

• Embed the object in a bounded grid; transforming the control points of the grid causes the object to transform accordingly
• Ex: https://www.youtube.com/watch?v=Bhilhg0rQtY

30.10 Kinematics and Inverse Kinematics

• forward kinematics: Given skeletal transformations, transform model
• inverse kinematics: Given model transformation (ex: I want the hand to be at (0,0,0)), find skeletal transform to achieve it (what angles should all the joints be at to achieve the hand in the given position)

30.11 Physically-Based Animation

• Forward Dynamics: Given forces, determine model
• Inverse Dynamics: Given desired state, determine necessary forces

Spring-Mass Models

• only briefly covered the math
• I think this is similar to FFD, except the grid has 'springs' between each of the control points (also masses here), and you apply forces to the grid

30.12 Human Motion

• Walking is hard
• Walking realism follows 'uncanny valley' graph (not proven): See #file-uncanny-valley-svg

30.13 Sensor-Actuator Networks (SAN)

• links: like bones
• sensors:
  • touch sensors: check if touching something (i.e. avoid foot going through the ground)
  • angle sensors: joints
• actuators: sort of like constraints? On angles (joints) or length (stretchiness?)

30.14 Biologically-Based Simulation

• Simulate how muscles contract; minimize metabolic energy to improve walking
• Ex: https://www.youtube.com/watch?v=r_c66EZAqrI

uncanny valley.svg

<svg
  xmlns:svg="http://www.w3.org/2000/svg"
  xmlns="http://www.w3.org/2000/svg"
  version="1.1"
  viewBox="0 0 151.21909 103.69006"
  height="103.69006mm"
  width="151.21909mm"
  style="background:white">
<g
    transform="translate(-1.032891,-84.554989)"
    id="layer1">
  <path
      d="m 21,95 v 72 H 141"
      style="fill:none;stroke:#000000;stroke-width:1;" />
  <text
      y="178.1572"
      x="80.069344"
      style="font-size:6px;text-anchor:middle;font-family:sans-serif;">Realism</text>
  <text
      transform="rotate(-90)"
      style="font-size:6px;text-anchor:middle;font-family:sans-serif;"
      x="-132.7565" y="15.746707">Perceived Realism</text>
  <path
      d="m 21,167 c 0,0 79,-54 86,-54 6,0 8,38 13,38 5,0 5,-55 5,-55"
      style="fill:none;stroke:#000000;stroke-width:0.75;" />
</g>
</svg>