January 22, 2011

These lesson notes accompany the video series Maya Dynamics - Catapult.Learning outcomes: Understand key concepts of Rigid Body dynamics
Modify the simulation with Gravity, Mass, Friction, etc.
Use dynamic constraints
Adjust Rigid Body Solver settings for the scene
Bake Simulation to convert dynamics to keyframes

1. Rigid Body dynamics concepts
   1. Dynamics are useful when an animation would be too complex to create by hand
   2. Modeling
      1. Rigid Body dynamics does not support deforming geometry
         1. Rigid Body dynamics uses the shape of the object on the first frame of the simulation
         2. If you want deformation, use nCloth instead
      2. Rigid bodies should have no construction history
         1. Edit > Delete By Type > History
         2. Hotkey: <SHIFT + ALT + D>
      3. Level of detail
         1. Maya’s Rigid Bodies are slow to calculate heavy scenes
         2. It’s common to create proxy objects as a workaround
            1. Create two LODs: high detail and super-low detail (proxy)
            2. Put the two sets of objects on different Display Layers
            3. Parent Constrain high detail objects to proxy objects
            4. Apply dynamics to the proxy objects
            5. Only render the high detail objects

July 8, 2011

These lesson notes accompany the video series Maya Dynamics - Breakage.

Learning objectives:

Model the shards of a broken object
Animate the initial movement with keyframes
Switch dynamics on at a certain time
Push rigid bodies in a desired direction
Fine-tune rigid body and solver attributes
Bake the simulation to keyframes
Toggle visibility to achieve “object substitution”
Render a preview animation

1. Workflow overview
   1. This is an old-school workflow
      1. Newer methods do exist, e.g. DMM, Digital Molecular Matter
      2. The version of DMM bundled with Maya 2012 is just a demo, with severe limitations
      3. This “crippleware” version of DMM is unsuitable for our needs
   2. Model the shards of the broken object
      1. Shatter tool
      2. crackMe script
      3. By hand if necessary
   3. Create a simple rig including the unbroken object and its shards
   4. Animate the rig with keyframes
      1. Adjust the function curve in the Graph Editor to make the object accelerate
   5. Apply Rigid Body Dynamics to the shards
      1. Control movement with Gravity and Radial Fields
      2. Fine-tine rigid body and solver attributes
   6. Keyframe the visibility of the objects
   7. Calculate and store the dynamic solution with Bake Simulation
   8. Render the animation to disk with Playblast or Batch Render

February 2, 2011

These lesson notes accompany the video series Maya Particles - Magic Wand.

Learning outcomes:

1. Particle Systems concepts
   1. Good for special effects such as weather, fog, crowds
   2. Many attributes to adjust
   3. Working with particle systems is an industry specialization within effects animation
2. Dynamics > Particles > Create Emitter
   1. An emitter generates particles over time
   2. An emitter may be animated directly or linked to a parent to make it move
   3. There are different Types of emitters; we are using the default Omni
3. Emitter attributes
   1. Rate is the number of particles born per second
   2. Speed is how fast the particles move away from the emitter
      1. Speed Random is a plus-or-minus factor
      2. For example, with Speed of 2, and Speed Random of 0.5, the range of possible speeds is 1.5 to 2.5
   3. Min Distance and Max Distance control particle birth location, distance from emitter
      1. For example, with Min Distance of 0 and Max Distance of 3, particles will be born within a radius of 3 units

February 19, 2011

These lesson notes accompany the video series Maya Particle Instancer - Butterflies.

Learning outcomes:

Model and animate a simple articulated insect such as a butterfly
Convert the animation to a model sequence using Animation Snapshot
Prepare the Snapshot hierarchy for use with the Particle Instancer
Sketch particles with the Particle Tool
Instance geometry to particles with the Particle Instancer
Write a Creation Expression to drive a custom attribute
Employ Radial Fields to attract and repel particles from one another
Fine-tune Field attributes such as Max Distance and Attenuation

1. Modeling
   1. Establish a scale convention
      1. For a small insect such as a butterfly, 1:1 scale makes sense
      2. By default, one standard Grid line is one centimeter
   2. The model must face in the world’s positive X axis
      1. The usual convention for character/creature modeling is that the model should face in the world’s positive Z axis
      2. This time we must do it differently, because the Particle Instancer has this special requirement
2. Create the insect body
   1. Build in Top view, Snap to Grid
   2. Create > CV CurveTool
      1. Options:Curve degree = 3 Cubic
      2. Click twice to create sharp corners
         1. Wait a heartbeat between mouse clicks, don’t double-click
      3. Don’t close the curve
   3. First and last control vertices must have a Z position of zero
      1. If you haven’t snapped to the grid, then you can move the CVs manually
      2. Method one
         1. Select the end CVs
         2. Click-hold and drag a selection rectangle around the endpoints to select multiple points at the same location... don’t just click once
         3. Channel Box > CVs (click to show)
      3. Method two
         1. Select the end CVs and choose the Move tool
         2. Input Line at the top right of the Status Line (top toolbar)
         3. Click the down arrow and choose Absolute Transform mode, if necessary
         4. Set Z value to zero
   4. Object mode: Surfaces > Surfaces > Revolve > Options
      1. Axis Preset: X
      2. Output Geometry: Polygons
      3. Type: Quads
      4. Tessellation Method: General
   5. Attribute Editor: nurbsTessellate node > General Tessellation Options