View Full Version : PAL Fields rendering help.

02 February 2006, 01:00 AM
Hi I need to render out a short 10 second animation for PAL Asutralia broadcast but am getting a little confused with the fields part.

Im told I need to render PAL ODD fields with upper fields dominance from the top, but in render options it says ODD is NTSC, so how to I render PAL ODD?

I set it to render 'interlaced both' and have rendered it with both PAL EVEN AND NTSC ODD as .tiff's with alpha, but was told it has to be PAL ODD, ???? please help me solve this.(When rendering with 'interlaced both' I only got a single file per frame, I was told there should be 2 per frame)

I plan to bring it into After Effects so I did this and then interperated the improrted frames with upper fields and exported that as well, I guess I want ot know the rendered frames from Maya are correct first.

Help would be appreciated thanks.

02 February 2006, 02:20 AM
For Australia, PAL is "even" (unless you are using DV format). In After-effects lingo that's "upper field first".

02 February 2006, 02:17 AM
Thanks for reply, I tried it a different way, rendering my animation at 50fps, problem is my 10 second 360 degree animation loop jumped from 250 frames to 500 (which makes sense) but the last 250 frames now have no motion.

So I cut my end frame at 250 frames and pasted it at 500 so it spins 360 from frame 0 -500.

Now when I bring it into After Effects, I interpret it at 25fps but it still says its 20 seconds long, I scale it down to 10 seconds and it doesnt loop smooth.

Should I not have cut and pasted the keyframes to adjust to the extra 250 frames created when settings scene to 50fps??

Im sure I would eventually figure it out but the 500 frames take 6 hours to render, if someone can help me without me needing to spend all that time re rendering you would rock.


02 February 2006, 03:11 AM
Rendering 500 frames seems like overkill if you only need 250 (Although I have done this once myself when I was dis-satisfied with the aliassing that resulted from a standard field render).

If you are trying to make it loop, then you need to be careful where you put the key frames.
If frame 250 is to be the same as frame 0, then when you construct the loop, you only need to render 0-249 (which is 250 frames long) The keyframe should be the same at frame 0 and 250 (even though you dont render frame 250) AND the tangents of the curves need to be set so that the curve becomes more-or-less continuous accross the jump, otherwise you will still perceive a slight jarring effect.

So in your case I think you at least need to throw away the last two frames (499 and 500)before doing the squash down to 10 seconds. That may still not be perfect though, because the last keyframe really should have been at frame 499, not 500. And then theres still that tangent problem to consider.

Btw, are you using quicktime or something to see it loop? I have noticed that many media players drop a frame or 2 or worse at the loop point when they are playing in repeat mode.

02 February 2006, 03:39 AM
Thanks again for reply.

I understand what you mean by rendering 1 less frame, I seem to be getting confused once I change to 50fps, the fact that I saw no motion after frame 250 has me stuck.

I originally had 250 frames, keyframe at frame 0 and 250 and rendered 1-250. The curve tangent is linear, (the sharp corner one :) ) so its exactly the same at 0 as it is 250.

1/ So when it doubles my frames and time, is it correct that I would only need to render 1-500 or 2-500 for it to loop smoothly?

2/ And if there is no motion after 250 will that get fixed in After Effects when I interperet it back to 25fps or should I actually adjust the keyframes to match the new 500frame scene then manually scale it back to 10sec in AE?

I have simply been using wireframe in Maya in viewport, scene isnt very detailed, so if loops smooth there its usually rendered smooth, its just the steps after I change it to 50fps, its probably so simple but Im making it sound more difficult.

(I am adjusting the frames to PAL 50fps fields through preferences)

02 February 2006, 12:38 PM
I think there is an option to keep the original keyframes when you change the fps. I think you should uncheck this. If you do it correctly the keyframe that was at 250 will move to 500.

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