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Tom Wood
10-08-2003, 09:19 PM
Hi All,

I'm trying to get some benefit from my dual-processor machine. I've determined that multi-threading is actually -slower- with simple animation images like I am making. The consensus on this board was that it takes LW longer to set up the multi-threading than it is worth for a simple image.

So I decided to open two instances of Lightwave and process half of the frames from each instance. But if I render out as an animation, it saves only a few frames in each. The render process window shows each frame being rendered, and it takes the full amount of time, but the resulting file only has a second or two of material when there should be thirty seconds. When rendering out the animation as one file from a single instance of LW it works (but takes twice as long).

BTW, I tried this with -hyper-threading enabled and opened four instances of LW, each assigned to a CPU (Xeons produce a 'virtual' processor) but it has no benefit because the render times just double. This machine is determined to make me wait....

Any suggestions?

Thanks,

TW

Mylenium
10-08-2003, 11:46 PM
Let's se if I got this right:

a) You use two instances of LW for rendering, each with 1 thread. That's ok.

b) You're saving to an animation file. Well, unwise, but ok so far.

c) Both you're instances access the same animation file? That's damn wrong!

You cannot have write access from two programs to the same file, especially not such complex things like animation files. This is a common dogma on most file systems to maintain file integrity so the blame can't go to LW. If this is what you were doing, than that's why everything screwed up. In addition to this this will become even more dramatic if you use compression since many frames will not be stored in full but rely on data from frames before them.

Mylenium

Tom Wood
10-08-2003, 11:52 PM
Ah, okay, thanks Mylenium. I didn't know that. So the solution would be to make a copy of the Lightwave scene file with a new name, and then access them separately with each instance of Lightwave? I was already -writing- the animation to separate files, but it was processing from the same Lightwave scene file.

Tom

danielkaiser
10-09-2003, 01:29 AM
Render to seprate files i.e. PNG's then convert to an animation file this will take care of the problem, saving direct to a animation file should only be used for small tests.

Dan

Mylenium
10-09-2003, 04:50 AM
Ah, I see. No, don't create another scene file - as long as you read them only (which the renderer does), there's no need to worry. However, the only solution to your problem is using image sequences. You see, both instances use the same CoDec but a CoDec can only used by one program at a time (at least most of them, only few are multithreaded/ -instanced). A CoDec belongs to the system and LW only provides tools for accessing it, therefore you cannot change this behavior. Quite often this is even noticeable in programs such as Premiere or AfterFX - if you read a file that uses a certain CoDec and want to compress it again with the exact same CoDec you get error messages.

Mylenium

Tom Wood
10-09-2003, 08:13 AM
Thanks.

That's the other thing, when I tried to save out to .tga or .rtv as separate files, I get one frame per frame, even though I specified in Camera-Properties that I wanted video fields. For example, a 60 frame scene yielded 60 frames, but shouldn't the end result contain 120 frames if I want video fields? Or is the field info somehow embedded in the format?

Thanks again,

Tom

Mylenium
10-09-2003, 08:22 AM
The fielding will be embedded into the image. You will see jaggy edges with fast movement. After all, fields are only needed by the video hardware for properly displaying images on TV monitors.

Mylenium

Tom Wood
10-09-2003, 09:12 AM
Originally posted by Mylenium
The fielding will be embedded into the image. You will see jaggy edges with fast movement. After all, fields are only needed by the video hardware for properly displaying images on TV monitors.

Hmmm....Just trying to follow the recommendations in the manual. I'm doing animation of characters like the one under my name. Most of the image is smooth, but the top and bottom of the mouths do go jaggy when moving quickly. The curve for the mouth animation is coming out of MagpiePro and it is faithful to the audio. Should I ignore fields while saving the images since they will be assembled in VTEdit? The end product is DVCAM tape for broadcast and DVD for marketing.

Thanks,

Tom

Mylenium
10-09-2003, 12:54 PM
Nope, don't ignore fields! You can render without them, but should be aware that add some time during production all footage will become interlaced if intended/ fielded for standard NTSC or PAL. So you will be facing the problem anyway (along with some other traps). I would talk to the people editing your animation and creating the DVD. They will tell you more about it.

Mylenium