9

954 Glossary
Hotspot/Fa lloff
Hotspot a nd falloff cones, highlighted in red.
You’ve seen how a flashlight or a theater follow spot
casts a circle of light. Depending on the quality of
the flashlight, or the adjustment of the follow spot,
theedgeofthecastpooloflightiseitherblurred
or sharp .
In the case of a blurred pool of light, the bright
circle in the center is the hotspot, which has an
even intensity. The outer extremity of the lig ht,
where it meets the darkness, is the falloff. The
difference in circumference between the hotspot
and the falloff determines the relative sharpness of
the pool of lig ht. For example, if the hotspot and
falloff are nearly the same size, the po ol of light has
asharpedge.
Thehotspotangleofaspotlightmustalwaysbe
smaller than the fa lloff angle. Put another way, the
hotspotmustalwaysbeinsidethefalloff.
Yo u c a n h o l d d o w n t h e
Shif t key to have the
hotspot and falloff values affect each other. If you
increase the hotspot to be larger than the falloff,
the falloff is increased as well. Likew ise, if you
reduce the falloff to be smaller than the hotspot,
the hotspot is also reduced.
IGES (Initial Graphics Exchange
Specif ica tion)
The Initial Graphics Exchange Specification
(IGES) is an ANSI standard that defines a
neutral form for the exchange of information
among dissimilar computer-aided design (CAD),
computer-aided manufacturing (CAM) systems,
and computer visualization systems.
3ds Max implements the IGES standard for
translating files to the software f rom IGES file
formats used by the mechanic al engineering
and entertainment industries. Using the IGES
import feature, you can read in native NURBS
(page 3–980) data b etween 3ds Max and other
programs such as Autodesk Mechanical Desktop®
(release 3.0 or later), Maya®, Pro/ENGINEER®,
SOFTIMAGE®, C ATIA®, and others. For complete
details on the IGES standard, see The Initial
Graphics Exchange Specification (IGES) Version
5.3.
IK Blend
In biped f reeform animation (page 3–945),the
IK Blend parameter determines how forward
kinematics (page 3–944) and inverse kinematics
(page 3–958) are blended to interpolate an
intermediate position. Using an arm to move a
hand is an example of forward kinematics. Using
the hand to m ove the arm is an example of inve rse
kinematics.
This parameter is located in the IK section of the
Key Info rollout (page 2–954).
IK Goal
In history-independent inverse kinematics (HI IK)
(page 2–446) and the IK Limb Solver (page 2–472),
the IK goal is the object ass ociated with the end