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Download the Mac LightWave 6.5 Updater!

Setting up ScreamerNet II for the Mac

[Page 3 of 5]

Host setup
The term "Host" refers to to the machine from which we will control the rendering. It will normally be the machine to which you have attached your hardware key (dongle) and probably do much of your modelling and animating work on. Using the method described in this tutorial, you will not be able to continue working with Lightwave whilst you are rendering, so it's something you will normally setup at night before you go home (if indeed you ever go home).

1. The "LWSN cmdline" file

This file contains a single line of code that LWSN uses to direct it toward two vital locations for its successful operation: the preference file for Lightwave Layout and the content folder from which you wish to network render. It also contains information about which specific 'Node' each instance of LWSN is controlling. You'll see this more clearly in a while.

Double clicking the file "LWSN cmdline" from within the 'Host' machine's Programs folder, should open it up in your default text editor, usually Simpletext. It should already contain a line of code which we are going to alter. For my fictitious project called 'the-worm' it would read as follows:

-2 -c"DavidT:System Folder:Preferences:" -d"DavidT:**PROJECTS:the-worm:" job1 ack1

The first part of this line -c"DavidT:System Folder:Preferences:" is going to direct LWSN towards our application preferences. On Macintosh, Preference files are almost always located within the System Folder -> Preferences. You should exchange the hard disk name "DavidT" for your 'Host's' hard disk name.

The second part of the line -d"DavidT:**PROJECTS:the-worm:" directs LWSN toward your current content folder; the project from which you wish to render. Directories are always followed by a colon and the quotation marks are required if there are any spaces in the names of your directories. I always include them anyway.

The last part of the line "job1 ack1" is used by LWSN to distinguish the differing 'Nodes'. The 'Host' machine could also be thought of as 'Node1' hence the use of the number one in this version of our "LWSN cmdline".

2. Multiple Node Folders

Because of changes in ScreamerNet II for 6.5 we must now create multiple copies of LWSN; LWSN cmdline and various other files that LWSN relies on. There will in fact be a different copy of these files for each rendering 'Node' on our network. Therefore, in order to stay organised, we'll create a folder for each 'Node' and put the relevant copies in each one. Below is a screenshot of the folder I created for 'Node2'. Remember that these are DUPLICATES of the files, don't simply move these files from the main Programs folder.

Fig3.1 The necessary files for each rendering "Node."

The name of this folder is not actually important. We'll be directing our 'Nodes' to their respective folders later by hand, so the name I've given the one above "LWSN_node2" is simply a personal naming convention. for 'Node3' I created a folder called "LWSN_node3" and so on. These are all placed within the Programs folder as seen below. I've created some spares also, just in case I ever win the lottery and can afford ten machines!

Fig3.2 The new look of our Programs folder.

3. Altering the instances of "LWSN cmdline"

The duplicates of each of the files shown in fig3.1 are identical EXCEPT for the file "LWSN cmdline". For each instance of this file we must adapt it slightly.

For the instance found within "LWSN_node2" we must change it to the following:

-2 -c"DavidT:System Folder:Preferences:" -d"DavidT:**PROJECTS:the-worm:" job2 ack2

For the instance found within "LWSN_node3" we must change it to:

-2 -c"DavidT:System Folder:Preferences:" -d"DavidT:**PROJECTS:the-worm:" job3 ack3

You can see that the only change is in the "job" and "ack" numbers.

4. Changing Lightwave's Preferences

The final stage to setting up the 'Host' machine involves running Lightwave Layout and altering its own Network Rendering settings. These can be found from within Layout under Rendering -> Network Rendering...

At this stage all you need to do is set the "Command" directory path to your current content folder; the project folder from which you wish to render. This can be done by pressing the 'Command Directory' button and linking to the correct folder. With my fictitious project, it would eventually read as below. Also, make sure your current content directory is set to the same thing.

Fig3.3 The red box shows the Command Directory, which should be the same as your current content directory.

Once you've selected your Command Directory folder, you will be asked if you wish to initialize ScreamerNet. I would say 'Yes' to this, even though you have currently not readied your 'Node' machines. Doing this will clean out old job files and I just find that ScreamerNet seems a lot happier if you've initialized it at least once from Layout. After a few seconds you should be informed that "No CPUs were detected". This is fine for the moment.

Once you've set up Lightwave correctly as shown, quit out of Lightwave. This step is necessary in order for Lightwave's Preference file to be written with the new information. This, after all, is actually the file that LWSN will be referencing during rendering. You can re-run it again immediately if you like.

5. Run LWSN on your 'Host' machine

To test that everything is set up correctly, run the copy of LWSN that can be found in the main Programs Folder. This is the copy that will control our 'Host' machine's rendering.

All being well, LWSN should run and a window will appear with the text "LightWave command: init" being continuously written down the screen. If this doesn't happen and you get an error such as - Can't open file "job1". use the keystrokes "[Command] + [.]" to get out of ScreamerNet. Force quitting usually causes the machine to crash. Check all the above steps before trying again. Eventually it should work.

PHEW! That's it. You've finally set up your 'Host' machine ready for network rendering.

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David now works happily as a freelance 3D artist and visualiser in the UK. As a music graduate and all round Bon viveur, his breadth of creative and technical skills have turned him into an unusually well rounded individual for one who never gets out into the light of day anymore. He can be reached at [email protected]. Visit his site at http://www.todman.dircon.co.uk.

This article was reprinted with the permission of the author.