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COSI 164A Intro to 3D Animation

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Symbols count in article: 9.2k Reading time ≈ 8 mins.

Lesson01 08/24/2022

  1. words
    • reflective
    • refractive 折射的
    • pan 移動拍攝
    • cone 圓錐
  2. Blender operations
    • Typical workflow: select an object, modify its properties
    • Changing view:
      • Arbitrary change: press middle mouse button and drag, or you can drag the xyz coordinates on the top right corner
      • Pan view(horizontal / vertical movement only): press shift key and press middle mouse button and drag
      • Zoom in/out: scroll up/down with middle mouse button
      • You can also use the view panel to change view direction
    • Deleting an object: select the object and press key x
    • Adding a new object: use the add menu to add a new object, or you can use SHIFT + A to add a new object
    • Transforming objects
      • Scale: select the object, press S, then drag to scale the object, left click to confirm/right click to cancel, use S + X/Y/Z to scale along the x/y/z axis. You can use S (+ X/Y/Z) + a number to scale the object to a specific size
      • Rotate: select the object, press R, then drag to rotate the object, left click to confirm/right click to cancel, use R + X/Y/Z to rotate the object along the x/y/z axis
      • Translate(move): select the object, press G, then drag to move the object, left click to confirm/right click to cancel, use G + X/Y/Z to move along the x/y/z axis
    • Duplicate objects: select the object, then SHIFT + D to duplicate the object, you can duplicate multiple objects by selecting multiple objects and then SHIFT + D
    • Set the parent of an object
      • If object A is the parent of object B, then object B will move along with object A
      • How: select object B, then select object A, then press CTRL + P to set object A as the parent of object B
      • If there are multiple objects selected, then the last selected object will be the parent of the other selected objects

Lesson02 08/29/2022

  1. Blender operations
    • Change the origin of an object: select the object, choose set origin in the object menu, then origin to 3D cursor
  2. Simple mesh objects...

Lesson03 08/31/2022

  1. Materials

    • Principled BSDF(bidirectional scattering distribution function): the most commonly used material
    • BSDF is a superset and the generalization of the BRDF(bidirectional reflectance distribution function) and BTDF(bidirectional transmittance透光度 distribution function)
    • Change the viewpoint shading options to view the materials: wireframe綫框, solid (materials invisible), material preview(use Eevee as renderer), rendered (can use other renderers)
    • Change the shading of an object: select the object, click the object menu, choose Shade Smooth(default is Shade Flat)
    • Make the surface reflective: metallic = 1, roughness = 0, change the render engine to Cycles
    • If you use the Cycles renderer, you let the renderer use fewer samples, so your computer will not stuck and the whole process will be faster

  2. Mesh editing

    • Use Tab to change between Object mode and Edit mode
    • In edit mode, you can select vertices, edges, and faces
    • You can create a material and assign it to part of an existing object

  3. Simple material objects

    The plane below is totally reflective

Lesson04 09/01/2022

  1. Subdividing a plane

    • Change from object mode to edit mode, select the whole plane, and choose Subdivide in the Edge menu
    • You can number of cuts inside one subdivision

  2. Proportional Editing

    • If you want to edition to a vertex influence its neighbors, you can use proportional editing
    • All vertices inside the target circle area will be affected, you can use the middle button to change the size of the circle
    • When you are done with proportional editing, you should turn it off to avoid accidentally editing other vertices

  3. Extrusion modeling

    • Extrude Faces duplicate faces, while keeping the new geometry connected with the original vertices
    • Change from object mode to edit mode, select the face you want to extrude, use shortcut E to extrude, or use the Extrude faces in the Face menu

  4. Modifiers

    • Modifiers are automatic operations that affect an object’s geometry in a non-destructive way
    • With modifiers, you can perform many effects automatically that would otherwise be too tedious to do manually and without affecting the base geometry of your object

  5. Simple objects

    This is a picture of my room, it contains a L-shaped desk with a computer on it, an office chari, a floor lamp, a book shelf and a bed

Lesson05 09/07/2022

  1. Textures (纹理) Intro
    • There are two types of textures: environment textures and object textures
    • You can use online texture websites to find textures
  2. Environment textures
    • Change from layout to shading in the top menu
    • Select the World option in the shader type menu
    • Choose a source file for the environment texture, and link its color property to the surface property of the World Output
    • You need to change the Viewpoint Shading to Rendered to see the environment texture
  3. Object texture
    • Change from layout to shading in the top menu
    • Select the Object option in the shader type menu
    • Use the Add button, choose Shader, then choose Principled BSDF
    • Drag a source texture file into the shading view, link its Color property to the Base Color property of the Principled BSDF
    • Link the BSDF property of the Principled BSDF to the Surface property of the Material Output
    • You need to change the Viewpoint Shading to Rendered to see the object texture

Lesson06 09/08/2022

  1. Material nodes
    • You can choose different shaders to create different surfaces
    • You can combine different shaders on the same object: create multiple shaders, then use them as inputs of the Mix Shader node, and then link the Mix Shader node to the Material Output node. You can also choose the weight of each input shader
  2. UV Mapping
    • Click the UV Editing button in the top menu
    • The surface of a 3D object is mapped to a 2D figure on the UV plane
    • You can move, resize, rotate the figure on the UV plane as you do in the normal layout view

Lesson07 09/12/2022

  1. Text
    • Create text and then convert it to mesh(object->convert->mesh), then you can add materials to it
    • Then you add modifiers: add modifier -> solidify -> change thickness
  2. Light
    • You can add different types of lights: point light, sun light, area light, spot light
    • You can change the color, power of your light

Lesson08 09/14/2022

  1. Use normal map(法线贴图) to create objects with uneven surface(imitate roughness)
    • Create two Image Texture
    • Connect one Image Texture to the Base Color of Principled BSDF, connect the other to the Normal of Principled BSDF
    • Connect the BSDF of the Principled BSDF to the Surface of the Material Output

Lesson09 09/15/2022

  1. Practice for the coming quiz

Lesson10 09/19/2022

  1. Use Texture paint mode to paint textures on an object

Lesson11 09/20/2022

  1. Transformation of point \(q = (x, y, z)\)

    • Translation: \(T_{p}(x, y, z) = (x + a, y + b, z + c)\), where \(p = (a, b, c)\)

    \[ T_{p}(x, y, z) = \left(\begin{array}{cccc} 1 & 0 &0 &a\\ 0 & 1 & 0 &b \\ 0 & 0 & 1 &c \\ 0 & 0 & 0 &1 \\ \end{array}\right) \left(\begin{array}{cc} x \\ y \\ z \\ 1 \end{array}\right)= \left(\begin{array}{cc} x + a \\ y + b\\ z + c\\ 1 \end{array}\right) \]

    • Scaling: \(S_{p}(x, y, z) = (a * x, b * y, c * z)\), where \(p = (a, b, c)\)

    \[ S_{p}(x, y, z) = \left(\begin{array}{cccc} a & 0 &0 &0\\ 0 & b & 0 &0 \\ 0 & 0 & c &0 \\ 0 & 0 & 0 &1 \\ \end{array}\right) \left(\begin{array}{cc} x \\ y \\ z \\ 1 \end{array}\right)= \left(\begin{array}{cc} a * x \\ b * y\\ c * z\\ 1 \end{array}\right) \]

    • Rotation: let \(s = sin(\alpha), c = cos(\alpha)\)

    \[ R_{\alpha}^{z}(x, y, z) = \left(\begin{array}{cccc} c & -s &0 &0\\ s & c & 0 &0 \\ 0 & 0 & 1 &0 \\ 0 & 0 & 0 &1 \\ \end{array}\right) \left(\begin{array}{cc} x \\ y \\ z \\ 1 \end{array}\right)= \left(\begin{array}{cc} c * x - s * y \\ s * x + c * y\\ z\\ 1 \end{array}\right) \]

    \[ R_{\alpha}^{y}(x, y, z) = \left(\begin{array}{cccc} c & 0 &s &0\\ 0 & 1 & 0 &0 \\ -s& 0& c &0 \\ 0 & 0 & 0 &1 \\ \end{array}\right) \left(\begin{array}{cc} x \\ y \\ z \\ 1 \end{array}\right)= \left(\begin{array}{cc} c * x + s * z \\ y\\ c * z - s * x\\ 1 \end{array}\right) \]

    \[ R_{\alpha}^{x}(x, y, z) = \left(\begin{array}{cccc} 1 & 0 &0 &0\\ 0 & c & -s &0 \\ 0 & s & c &0 \\ 0 & 0 & 0 &1 \\ \end{array}\right) \left(\begin{array}{cc} x \\ y \\ z \\ 1 \end{array}\right)= \left(\begin{array}{cc} x \\ c * y - s * z\\ s * y + c * z\\ 1 \end{array}\right) \]

  2. Transformation can be composed

Lesson12 09/22/2022

  1. Animation
    • Default 25 frames/second
    • Use i to insert a keyframe, you can change location, rotation, scale and other custom properties of the object
    • Modify Output Properties to change the output format to AVI JPEG, then render animation, there will be an avi file in the output folder

Lesson 13 09/29/2022

  1. Exam 1 on modeling: got 100/100

Lesson 14 09/29/2022

Lesson 15 10/03/2022

  1. 3D printing

Lesson 16 10/06/2022

  1. Jump lamp example

  2. Use armature to add bones to the model

    • Select Layout model, then select Add -> Armature

Lesson 17 10/12/2022

  1. Add armature
    • Use Ctrl + Alt + Q to change to a quad view and back
    • Make sure that the armature is inside the object when you setting the parent(so some neighbor points are assigned to the armature), the armature should be the parent of the object, and use the With Automatic Weights mode to automatically assign points
    • Use the Pose Mode of the armature to change the position of the bones as well as the object
    • If you cannot see the armature, Click the Object Data Properties on the right, in the Viewport Display section, check the In Front option in the Show section
    • Select the armature and the object to which is the child, then select the Weight Paint mode, then you can adjust the influence of the armature on the object
    • You can change the end frame when rendering animation

Lesson 18 10/13/2022

  1. Makeup exam: did not take it because I got 100/100 on the first exam

Lesson 19 10/18/2022

  1. You can use some online free fbx human model and import it into blender, which contains both model object and its armature

  2. Rigify

    • Click the top left button, select Preferences, in the add-ons section, search rigify, check the Rigging: Rigify option
    • For human model, select Add -> Armature, then select Human(Meta-rig)
    • Use the Pose Mode of the armature to adjust its position

Lesson 20 10/19/2022

  1. Shape Key animation
    • Create an object model, click Object Data Properties on the right, Click + in the Shape Keys section to add a basic shape key
    • Add other shape keys, go to Edit Mode, click the shape key you want to edit, do some modifications on the model, then go back to Object Mode, adjust the value to show the influence of that shape key
    • For animation, select a key frame, pause your mouse on the value of each shape key, press i on the keyboard, then move to the next key frame

Lesson 21 10/20/2022

  1. Practice exam 2

Lesson 22 10/24/2022

Lesson 23 10/25/2022

Lesson 24 10/27/2022

  1. Practice exam 2 (this should be exam 2, but there was an network error in the classroom)

Lesson 25 10/31/2022

  1. Exam 2 on animation: got 100/100

Lesson 26 11/02/2022

  1. Class cancelled...

Lesson 27 11/03/2022

  1. Reviewing CPA 2

Lesson 28 11/07/2022

Lesson 29 11/09/2022