HiRes renders, reduction to PAL in After Effects and staircase effect

[Juanxer]

In order to be able to reframe EIAS-rendered footage into a PAL-sized comp (720x576 interlaced), sometimes I render at, say, 1024x768 and scale and move things while in After Effects. The problem is: I get severe staircase effects even if I render it field-less (flicker is easier to correct, though).

Does anybody have any recipe or suggestion to deal with that?

[fantomaz]

Are the pixel ratio the same?

I always use square pixels in EI -> 1024x576 -> when 16:9 in PAL is needed,

or 768x576 when 4:3 in PAL is needed.

All Adobe products are aware of that setting.

And look for DV compression in AE, its 1:1.07.

You get wired things (not only stretched spheres) on the screen sometimes.

Alex

[Juanxer]

I have things set up so that pixel ratios fit: the final comp is a D1/DV type one, so squared pixel-type layers are scaled accordingly by using the checkbox in the scale values dialog box.

Anyway, I am learning about some things that contribute to my problems. For one, I was applying some Levels and things to RPF-isolared elements direclty instead of applying them to layers masked via those very RPFs. The problem with layering an RPF-derived element directly into the comp, I am finding out, is that it accentuates and so damages its borders (at least given how those elements were generated, backgrounds or alphas-wise). By using it as masks for the original material, I seem to avoid the problem.

Also, I guess I ought to go antialias-crazy when rendering oversized elements to reduce and reframe into the relatively low-rezziness of a PAL frame: scaling down the image sharpens it so the AA becomes reduced. On an interlaced PAL frame, given its relatively low resolution, it gets quite troublesome.

I've re-rendered things closer to or at the final size required, using Oversample 0-255 and upping the AA to 8x8; comped things using RPFs just as mask sources, and it seems to have eliminated most problems. Tonight I'll render a batch of AA 16x16 passes to compare with the last one.

It is obvious I must learn more about these things.

[Tomas Egger]

Hi Juanxer,

- Most of my renders are done in Adaptive 4x4 - 1x1, since real footage which I always integrate (real life) its always have more blur, I always give some blur in my 3d renders.

If I see some edge flick (shaders for example), I use Adaptive 8x8 - 2x2 at most, never more.

- All textures are converted to .img, faster to render.

- I never render using field, you always can render using 24 or 25 frames and in after effects use 3:2 pull down to add the fields there, so, you will have less frames to render inside EIAS.

- You can always use track mattes on After to protect your AA edges, which you pointed out.

Thanks a lot

Tom

[Juanxer]

Hi, Tomas, thank you for your suggestions. Those AA 16x16 renders I am rendering will quite probably be overkill, but it will be interesting to see what comes out of it. I usually render 50 fps to derive 25i in AE and have some extra leeway if I have to retime the footage, but lately I've found After Effects' pixel flow retiming quite capable: actually, I ought to test what AE makes of those jaggies when retiming: would it smooth them out?

I'll post any further findings.

[Tomas Egger]

Ola Juanxer,

When you play your EIAS animation render in After Effects without any re-timing, it play smooth without jaggies?

if it plays perfect, its probably a re-timing prb, Do you use time-remap feature or only accelerate the entire footage in a linear fashion?

If you use any kind of time remap, please, enable in all advanced tab of Composition settings windows of your project, preserve resolution and preserve frame rate options ,that helps some time-remmaping problems, roto-spline masks mismatches and AA problems.

And finally, pay attention if your remaping produce less frames than your footage already have in realtime, otherwise, you will have artifacts because of lack of data.

Hope this help

Thanks

Tom

[Juanxer]

Thank you all for your advice :) Definitely this was a combination of not enough antialias, bad comping practices and working in PAL. Those re-renders solved nearly 90% of the jaggies. There are some that seem incurable, so I think I'll isolate and filter them with some masks.

And now I've found out that I need to provide anamorphic PAL (for 16:9 results). I was thinking about setting a pixel ratio of 1.78 or so (what is the precise value for that in EIAS?), but my brain was hurting and I have enough time left to try thingso, so I will render as 1024x576 and let AE or FCPro squash it. It should be interesting, although I suspect antialias would work best when rendered at the final resolution (which I'll try too): when EIAS antialiases things while in a non-1:1 pixel ratio rendering situation, is AA also non-1:1 or is that an independent thing, and a border is a border is a border?

Aw, that's what happens when one does a couple or three TV ads a year at most in a small ad agency. My country goes DTTV: instant rustiness. :D