September 25, 2008 Workshop 6 Notes

BOOLEANS AND NON-LINEAR DEFORMERS, IMPORTING SOUND

1. Booleans: Difference Operation; create two overlapping NURBS surfaces; choose Edit NURBS > Booleans > Difference tool; Click the object to remain; press “enter”; click object to remove; press “enter” (note history records and allows you to reposition original shapes). Middle figure below results from difference operation. First figure towards left results from union and last figure results from intersection of two overlapping spheres according to a similar dialog from the same menu Edit NURBS > Booleans.

Before	After

2. Rebuilding surface for stitching: select NURBS surface; Edit NURBS > Rebuild; enter 5 in u spans and 5 in v spans (note: spans evenly distributed).

Before

After

3. Attach two surfaces (try on two adjacent NURBS planes): select two NURBS surfaces to attach to each other; Edit NURBS > Attach Surfaces; From menu deselect “Keep Originals”; click Attach (two surfaces become one);

4. Duplicating Surface Curves

Create NURBS primitive cylinder; Edit Curves > Duplicate Surface Curves and select dialog box; Select the U direction and click “Duplicate”; curves are duplicated and can form basis of new curve. Or, select both. Example below from "both", initiated with flat 5 x5 planar surface modified at vertices to form a non-planar shape to which the Duplicate Surface tools was applied. The duplicated curves were then moved above the original suface to help see the result.

5. Nonlinear deformers allow surface geometry to be treated non-uniformly with respect to some modifications, either for the purpose  of constructing geometry or for the purpose of keyframing a transforming object.. These deformers are available under the animation module.

CASE 1: DEFORM>CREATE NONLINEAR > BEND DEFORMER Build a cylinder, 8 subdivisions axis and 8 subdivisions height, use channels box to modify it

• go to bend input, select curvature, and use mouse to modify values.
• Change low bound and high bound options to 0 to reduce bending on upper and lower portions of cylinder.
  
  
  

CASE 2: DEFORM>CREATE NONLINEAR > FLARE DEFORMER Build cylinder as in previous example;

• select start flarex and modify values with mouse in window.
• change lower bound properties and observe result.
  
  

CASE 4: DEFORM>CREATE NONLINEAR > SINE DEFORMER Build cylinder as in previous example;

• select amplitude and wavelength and modified values with mouse in window
  
  
  
  
• perform same operation on flat surface (100 x 100)
  
  
  
  
• note wavelength offset must be less than wave length
• note: drop off attenuates wave

CASE 5: DEFORM>CREATE NONLINEAR > SQUASH DEFORMER Build cylinder as in previous example;

• select “factor” and “expand” and modified values with mouse in window
• note that total volume remains constant unless value of “envelope” > 1
  
  

CASE 6: DEFORM>CREATE NONLINEAR > TWIST DEFORMER Build cube similar to  previous example;

• subdivide width, height and depth at 8 units
• select “start angle” and “end angle” and modified values with mouse in window
  
  

CASE 7: DEFORM>CREATE NONLINEAR > WAVE DEFORMER Build flat surface 100 x 100

• select amplitude and wavelength and modified values with mouse in window
  
  
  
  
• note wavelength offset must be less than wave length
• try drop off at 1 to attenuate wave
• key frame two different values for offset
• use dropoff value at 1 and increase amplitude (+ or - direction)
  
  
  
  
• Move surface and note change in position of concentric rings
• Modify radius
  
  
  
  
• Keyframe two different positions of defomer

6. Loading Sound: Sound can be imported into Maya for timing a animation and exported into a movie file through the playblast utility. Final rendered frames are then syncronized separately through sound editing software Sound Edit or Quicktime Pro.

You can’t import sound files into Maya some formats. However, you can use Quicktime Pro convert your sound files to Windows and Apple compatible file formats like aff. To convert a sound file in Quicktim Pro:

1. Load the sound into Quicktime Pro through the file open sequence.

2. Save the file to aif format.

To load an audio file into your scene (the instructions below are abbreviated from the Maya help documentation):

1. Use File > Import. A file browser lets you select the name of the sound file to import.

To display sound on the Time Slider:
1. Right-click the Time Slider. A pop-up menu appears.
2. In the pop-up menu, select the audio file you want to hear from Sound > audio file. The audio file’s waveform appears in the Time Slider and it plays during playback.
3. To change the start time for the sound. Select Display > Sound > NAME OF SOUND TRACK >and change the Start Time (Offset #) to the frame number at 24 frames per second. (frame 48 = 2 seconds at the default Time Unit of 24 frames per second). You will now see the sound waves representing the sound appear in the Time Slider starting at time 48.

4. To play your animation with sound, open the Animation Preferences window and ensure that Playback Speed is set to Real-time (24 fps) and click Play. The sound begins at 2 seconds (or time 24 on the Time Slider).