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174 Chapter 17: Rendering
In the software, one computer is set up as the
network Manager. The Manager "farms out"
or distributes the work to rendering Servers.
You can also have the same computer function
simultaneously as both Manager and Server, so
computing cycles don’t go to waste.
Once render ing is u nder way, the Queue Monitor
program lets you directly monitor and control the
operation of the network rendering workload. The
Queue M onitor allows you to edit job settings as
well as to act ivate, deactivate, and reorder both
jobs and servers involved in your render farm.
Impor t ant: When rendering using a render farm,
always render to single-frame formats such as
BMPorPNG.MoviefileformatssuchasAVI
depend on the ordered sequence of the frames. A
network rendering situation does not guarantee
that. Frames c an come in in any order.
The only way to guarantee the frame sequencing
in an AVI file is to render on a single com p uter.
If rendering with multiple comput ers, render
individual frames and, when all of them are
rendered, combine them in the proper sequence
with Combustion or Video Post.
How Work Is Divided
The software breaks up the task of network
rendering among the rendering Servers, assigning
one frame at a time to each Server. The completed
output of the Servers accumulates in a common,
shared directory.
Rendered frame files can also be written to a
local directory on each machine, if the same path
definesthedirectory.Framefilesaresequentially
numbered, making them easy to assemble later.
The Manager takes a number of different factors
into account in determining how to assign frames
and jobs, always str iving for the most efficient
usage of the rendering network. An idle rendering
Ser ver is automatically detected by the Manager
and is considered for job or frame assignment. If a
Ser ver goes off-line for some reason, the Manager
reclaims the Server’s current frame and reassigns
the frame to the next available rendering Server.
The B asic Process
Following is a step-by-step description of the
sequence of events w hen you use network
rendering:
1. The user submits a job to the network Manager.
2. On the submitting machine, the MAX file gets
zipped up. If the user turned on Include Maps,
all m aps and XRefs are also zipped up.
3. Oncethefileiszippedup,theZIPfile
is copied to the Manager machine’s
Backburner\network\jobs\jobname folder. In
the folder is an XML file describing the job
itself, specifying frame size, output filename,
frame range, render settings, etc.
4. Once the Manager receives the ZIP and XML
files, it looks to see which servers are sitting idle
and can render jobs. It assigns the job to four
servers at a time. (T his is the Max Concurrent
Assignments sett ing on the Manager Genera l
Propert ies dialog. See S
tarting Backburner
Manager ).
5. Each Server machine receives the ZIP and XML
files into the
Backburner\network\jobtemp
folder.
6. The MAX file gets unzipped, along with the
maps and XRefs if they were included.
7. 3ds Max is launched and loads the MAX fi le.
If the maps and XRefs were not included, the
software searches for t hem as they are defined
in the MAX file. For instance, if an XRef is
in
d:\foo\xref.max ,theServerwilllookfor
xref.max in d:\foo\ on the local machine.
If there are additional map paths set in the
3dsmax.ini file on the rendering server, it wil l
search in those paths as well. If it does not find