8

1048 Glossary
Hotspot/Falloff
Hotspot and 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 flash light, 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 ext remity of the light,
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 light. For example, if the hotspot and
falloff are nearly the same size, the pool of light has
asharpedge.
Thehotspotangleofaspotlightmustalwaysbe
smaller than the falloff angle. Put another way, t he
hotspotmustalwaysbeinsidethefalloff.
YoucanholddowntheSHIFTkeytohavethe
hotspot and fa lloff values affect each other. If you
increase the hotspot to be larger than the falloff,
the f alloff is increased as well. Likewise, if you
reduce the fa lloff to be smaller than the hotspot,
the hotspot is also reduced.
IGES (Initial Graphics Exchange
Specification)
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 from IGES file
formats used by the mechanical engineering
and entertainment industries. Using the IGES
import feature, you can read in native
NURBS
(page 3–1074)
data b etween 3ds Max and other
programs such as Autodesk Mechanical Desktop®
(release 3.0 or later), Maya®, Pro/ENGINEER®,
SOFTIMAGE®, CATIA®, and others. For complete
details on the IGES standard, see The Initial
Graphics Exchange Specification (IGES) Version
5.3.
IK Blend
In biped freefor m animation (page 3–1039) ,the
IK Blend parameter determines how
forward
kinematics (page 3–1038)
and inverse kinematics
(page 3–1052)
are blended to interpolate an
intermediate position. Using an arm to move a
hand is an example of for ward kinematics. Using
the hand to move the arm is an example of inverse
kinematics.
This p arameter is located in the IK section of the
Key Info rollout (page 2–809) .
IK Goal
In history-independent inverse kinematics (H I
IK) (page 2–427)
and the IK Limb Solver (page
2–454)
,theIKgoalistheobjectassociatedwith