Field Rendering Question LW + AE

[squidsquidsquid]

What is the proper way of rendering 60fps in LightWave and then importing the image sequence into After Effects and then rendering an interlaced animation? Is the composition set to 29.97 fps, and the sequence set to 60fps? Then just select the upper or lower field rendering in the render queue? Does using time-stretch (50%) on the image sequence have the same effect as setting the clip to 60fps?
I'm assuming the unseen frames are used during rendering to create the opposite fields.

Thanks to anyone who can clarify this for me.

[js33]

Hi squid,

I am assuming you want to render for NTSC playback.
You wouldn't want to render 60fps unless you want a slow motion effect. In Lightwave when you render with fields both fields are in the same image file. In Lightwave you will set it to 30fps and usually use odd fields first as most NLEs seem to use that. But do a small test first if your not sure (odd and even fields) and the one with the smoothest motion is the field order to use. If you use the wrong one the interlacing will look bad and should be very obvious.

If you render out single frames it's always 30fps as you always have 30 individual images per second so 29.97 means nothing to Lightwave in this situation.

So render out your single frame image sequence with the proper field order. Then import that to after effects using the correct field order there. Odd in Lightwave equals lower in After effects.
Then set your compostion in AE to 29.97 and render out to QT, AVI or whatever you're using. Usually you will render using the codec for the NLE that you are outputting for AVID, Digisuite, Media100, etc...

Hope that clears it up some.

Cheers,
JS

[squidsquidsquid]

I guess I could have been a bit more specific. The reason I want to wait to create fields until AE is because I plan on doing some resizing of the image sequence in AE. If I resize interlaced LW images in AE, I'm assuming I'll lose the proper field order. I thought I read a thread some months back where a process was described of bringing in double the amount of frames you need (into AE), and using the "inbewtween" frames as the odd or even fields.

I've doen the whole LW field rendering thing, and it works perfect 90% of the time. It's just that I need to do this manipulation that I'm pretty sure will throw off those LW fields or else render them useless.

[js33]

Yes it would mess it up if you resize.
But field rendering is pretty much useless unless going out to an NTSC device. (tv or tape)
What size are you starting with and what size do you want to end up with? I'm not sure what you are trying to do.

If you want to output field rendered output why not just render to the correct size to start with? (720x486 or 480) Unless it's for HDTV output.

Cheers,
JS

[NickLambert]

AE, if told the field order & motion detect
is set to on when interpretation is used will treat your interlaced footage as two seperate images. This has
worked fine for me...

[Beamtracer]

Squid, you're on the right track. Just render 60fps in LW and let AE handle the fields. Don't use any time stretching or motion effects.

[Avebeno]

I've done this before when I didn't know what my final output size would be...

Render my lightwave animation at 60fps

Bring the footage into After Effects, go to interpret the footage and set it to assume the frame rate of 60fps
with NO seperate fields.

Make your composition the final output size (720*486 / 720*480) and set the frame rate to 29.97 for NTSC video.

You don't need to do any time stretching and you can treat the footage like any other footage on the timeline.

When you output & render the final movie in After Effects you can then set the field priority to whatever you need for your delivery method.

[squidsquidsquid]

Thanks everyone for the advice. I think I've been doing it right (aside from the time stretching). Just wanted to make sure.

So am I right in assuming that during rendering, AE "looks" at those frames unseen in the composition window to make the alternating fields? ie: I'm seeing frames 1, 3, 5... and AE finds 2,4,6... and uses all of them to make the alternating fields? I realize I don't need to know this for it to work, I'm just curious.

Thanks again.

[js33]

Again I'm just wondering why you don't just render to the proper size to start with? Will save you alot of time.

Cheers,
JS

[squidsquidsquid]

js33, I'm layering a lot of seperate elements, and that's why I'm working in AE. I'm sure there are ways to do what I'm doing directly in LW, but for the way I work, I'm much quicker at AE. I guess I just need the flexibility of waiting to render fields at the last step, because I know going into AE that my elements won't be a perfect fit and will require some manipulation.

Hope that explains it.