i'm trying to render my compositing network. i know in Outputs there's a Composite generator so i'm using it. I've selected the proper cop network and the proper cop name (that which has the render flag on aswell). But the frames just render black. This only happens when the output picture is a sequence of images. If i output to the mplay window it works just fine.

any clues why i can't render a sequence of images?

From the information you have given me, I can't really say what you've done wrong.

It could be possible, if you have enabled the COP, TOP and MAT modules (via the environment variable), that you've chosen the wrong ROP. So check that:

COPs –> Composite ROP
COP2s –> Composite v2 ROP (standard with 5.5 )

If you had this right, which I presume you do, you could also check the file format you're exporting to from the ROP's output settings. Sequences are rendered via the following variable: $F. If you want to output composite.0001, composite.0002, composite.0003, composite.0004 .. etc. you use the following variable $F4 where 4 represents the amount of digits used in the sequence's filenames.

So, if you have an animation of 300 frames, you could use this as file output:
/usr/username/comp_out/anim1.$F3.tga

In the case of Windoze:
*driveletter*:\any_dir\comp_out\anim1.$F3.tga in the case of Windoze.

Finally, check if you're outputing at least R, G and B channels.

If you've selected the correct network, then it's not the COP/TOP/MAT problem - since a Composite V2 can't see a Composite V1. However, Calosus is correct, there's insufficent information to determine your problem. Try problem solving. Make a simple, new network with only a ramp. Output a sequence of that. If you still get black, then you're either doing something fundamentally wrong, or you've got a serious misconfiguration of the software(which is unlikely). At least that rules this out.
Have you checked permissions to where you're trying to write? I'm not sure what OS you're on. What specifically do you have entered in your “Output Picture” field in your output driver?

It's useful to give as much info as possible when looking for help. This is overkill, and not really our field, but I've found it's a good guide to live by:

http://www.tuxedo.org/~esr/faqs/smart-questions.html [tuxedo.org]

Cheers,

J.C.

sorry for the ambiguity, i was hoping it was an easy fix for a common problem.

Anyway, i tried problem solving like j.c. suggested. I used a ramp COPv2 and animated one of the colours from frame 1 to frame 300. This sequence rendered perfectly.

What i think might be causing the problems is that my images go from frame 263 to 601 instead of 1 to 300. So, anytime i try compositing where the begining frame ISN'T 1, it doesn't work except if i render in the ip or mplay.

When i use a file COPv2 with a sequence of .picnc files that don't start at frame 1, do i have to do something differently?

ok, if anyone cares, i've figured out one possible solution.

I noticed that if I just threw down a background colour behind my file sequence and rendered from frame 1 till the end, i would get a proper render with a bunch of empty frames preceeding the frames i desired to be rendered.

So, what i concluded from this so far, is that you can't just render in compositing starting at any frame. You have to start at frame 1. Also, the initial frames can't be empty, so you have to put something in them, of the same dimension as your other files, like a colour COPv2 or something.

Unless you've got a version with an extremely serious bug in it(unlikely), that's not the problem - I can start from any frame in the example you give and get the correct stuff. For instance, I have a sequence that starts at frame 10, and I output 9-20, and I get one black frame, followed by the first 10 frames of my sequence. I'm running 5.5.208, although as I say I'd be really surprised if such a serious bug got into a point release. Always possible, though!
Apart from incorrect names in the “Output PIcture” field or the possibility that you fiddled with the offsets and timing tools in COPs(stuff I'm not personally fond of - like having FPS assigned on the fly to sequences - which is simply incorrect IMHO), perhaps you should try 5.5.208?
Oh, and of course it's possible it's platform-related - you don't mention your platform, but I'm running Linux…

Cheers,

J.C.