8

Quadtree 1093
There are six additional markers for the top,
bottom, and middle of the two props. If these
tracks are detected, char acter studio creates a
3ds Max dummy object.
Thelengthofthepropistheaveragedistance
between the top and b ottom prop marker during
animation.Thepropwillbeorientedintheplane
of the three prop markers, and its or igin will be at
the b ottom prop marker.
Quadt ree
Aquadtreeisadatastructureusedtocalculate
ray-traced shadows (page 3–1094) .
Thequadtreerepresentsthescenefromthepoint
of view of the light. The root node of the quadtree
lists all objects that are visible in that view. If too
many objec t s are visible, the node generates four
othernodes,eachrepresentingaquarterofthe
view, each with a list of objects in that portion.
This process continues adaptively, until each
nodehasonlyasmallnumberofobjects,orthe
quadtree’s depth limit (which can be set for each
light) is reached.
Each shadow-casting light ray needs to test
intersection with the objects in only one of the
leaf nodes of the quadtree. This helps speed up
the ray-tracing process. In general, increasing
the maximum quadtree depth can speed up
ray-tracing at a cost of memory.
The maximum size of a quadtree is the s quare of
two to the power of the maximum quadtree depth.
At a depth of 7, the largest quadtree has 128 x 128
leaf nodes; at a depth of 10, the largest quadtree
has a size of 1028 x 1028 leaf no des, and so on.
(On the other hand, because each successive node
contains fewer objects, the size of a node’s record
decreases the deeper it is in the t ree.)
Note: An omni light can generate up to ten
quadtrees, so omni lights that cast ray-traced
shadows use more memory at render time than
spotlights do.
Queue M onitor
The Queue Monitor is a standalone
network-administration tool that provides
a user interface to monitor and con trol network
rendering.
The Queue M onitor can connect to any computer
to which you have network access with the
appropriate security permissions, and a Network
Manager r unning on it. You can install the Queue
Monitor separately. I t will function correctly on
any Intel-based computer running Windows NT
with appropriate TCP/IP networking services,
including over the Internet. In other words, you
can monitor and control network rendering
services from any computer connected to the
Internet, in addition to using the Internet as a
wide-area backbone for a network rendering farm.
Radiosity
A technique to calculate indirect light to illuminate
a scene. Radiosity calculates the interreflections of
diffuselightamongallthesurfacesinyourscene.
The result is the
radiosity solution (page 3–1093) .
See
Modeling Global Illumination w ith Radiosity
(page 3–50)
.
R a dios it y S olut ion
The calculation of the radiosity (page 3–1093)
effect in a scene. You compute the radiosity
solution as a separate step from rendering.
Once the solution is computed, it can be used
for multiple renderings. See
Modeling Global
Illumination w ith Radiosity (page 3–50)
.