Session 4: Special Effects

Image courtesy of CPO Digital: http://cpodigital.blogspot.com/

• Homework review

Get this week's files here.


Subjects:

IPR


Depth of Field

• lower f-stop = more blur
• use Heads Up Display > Object Details to get Distance from Camera
• see DOF.mb 
• Create > Measure Tools > Distance Tool and point-constrain one locator to the camera to create a sliding scale. Use the connection editor to connect distanceDimension1:Distance to renderCam:Focus Distance (see the file DOF2.mb)
  

Area Lights

• computationally more expensive
• yield softer lighting
• emits a number of rays according to a two-dimensional area
• size of light icon = brightness of light
• produces softer, larger highlights
  

Volume Lights

• allows light only in a specified boundary volume
• easy control of light's range
• falloff controlled by a color ramp in the Attribute Editor
  

Negative Light

• for faked “shadows,” put a light of negative intensity in an area to suck light out of that area
• use fast decay to contain it
• volume lights are particularly well suited for faking shadows: emit ambient and turn off diffuse and specular
• try using light linking or colored negative lights (hint: set it to the opposite of the color you want the shadow to be)
  

Light Effects

● Fog

• use with point, spot, or volume lights
• spot lights have intensity and spread
• point lights have type (normal, linear, exponential), radius, and intensity
• three types of fog in Maya: light, environment, and volume
• light fog is the default and most common. it can cast dmap shadows (other types cannot). Control these shadows in the light’s attribute editor under Depth Map Shadow Attributes>Fog Shadow Intensity & Samples
• change light fog to environment or volume by MM-dragging from the Hypershade (Volumetric Section) to the Light Fog attribute
• Environment fog is not controlled by particular lights, but exists everywhere within scene. Doesn’t cast shadows. Look under Render Options in the Render Settings window to apply it.
• Volume fog can exist within a volume primitive. Create>Volume Primitives. Adjust Dropoff type in Attribute Editor.
  

● Optical Effects

• create an optical fx shader on your light by clicking the checkered texture button next to the Light Glow field
• can create glows, halos, and lens flares
• use sparingly!
  

● Gobos

• create by mapping a texture to the color attribute of a light
• can create Gobos in Photoshop, use procedural textures or images you find on the web – black and white work best for “shadows”

Homework: hauntedhallway.ma

 

 

 Images courtesy of ImagineFX: http://www.imaginefx.com