Interpolated versus non-interpolated mouth positions

mkelley · Post by **mkelley** » Tue Feb 24, 2009 2:10 pm

Forgive me if this is a stupid discussion question, but I seem to have made a revelation and I just want to see if I'm grounded here or if my brain is playing tricks on me (at my age, certainly possible).

Setting aside all considerations of "other" kinds of animations (I don't want to get into a Disney, or Frame-by-frame, or what else can be done) and just concentrating on the use of the Papagayo DAT file/mouth layer positions in AS, does anyone other than me think it's much better to use them non-interpolated versus interpolated?

Here's what happened -- I've designed my own mouth positions, carefully, using the Preston Blair guidelines but making them interpolated so that the lips, teeth and tongue can morph from position to position. I've been using them like this for over a year now. Someone watching our show commented that the teeth looked odd, like they were false teeth, and it really bothered them.

I went back to watch and compare and lo and behold if you use interpolation it does indeed look like the teeth "float" in a way that's very unnatural. Turning off interpolation solves this -- indeed, at 30fps (my project settings) I think it looks much BETTER with interpolation turned off.

As a former 3D person this goes against my grain -- it seems like the lips should definitely morph to be proper, but perhaps since the movement of lip sync (at least at the cartoon level I'm doing) just looks right without it. Indeed, it looks "stronger" in some way I can't quantify.

Does this make sense to anyone else? Before I completely switch my whole TV series design I'd like to at least get some feedback from others who may have already faced this issue.

Once again -- I'm not trying to open up a can of worms here. You may do lip sync some completely different way and that's fine. Or perhaps you do your projects at 12fps -- that won't compare, either. I'm just talking about a 30fps (or perhaps 23fps) project using the sort of mouth layers provided by AS and using Papagayo to produce the DAT file. If you work some other way, please stay out of this thread, thank you very much.

synthsin75 · Post by **synthsin75** » Tue Feb 24, 2009 2:25 pm

Hey Mike,

I tend to not animate the teeth shape, they are attached to the skull after all <bg. But I know that certain styles tend to be more flexible with them. At least for me, I'm not sure non-interpolated would help altogether since they would still seem to move anyway. I might have to see the difference to be sure though.

But overall non-interpolated lip-sync should be fine even at 30fps. When I do interpolated lip-sync, I reduce the number of phonemes (by duplicating the same layers for several) to keep fast dialog from looking too muddled.

Just my two cents.

mkelley · Post by **mkelley** » Tue Feb 24, 2009 2:38 pm

Wes,

I just went through some frame by frame studies of American Dad (for reasons you know) and it's clear they don't interpolate mouth shapes at all. Now, I'm sure this is a cost measure, but it makes the dialog seem a lot more "snappy".

I need to see if this holds up on someone speaking extremely slow, but so far I'm convinced I've been doing it wrong. I'm surprised no one has brought this to my attention before (my stuff has been seen by a lot of people -- but, as you know, only lay folks so perhaps that's been my own fault for not showing it around more) but if I can improve now no harm has been done (in some ways it's kind of charming -- ever seen the early "Simpsons" on the Tracey Ullman show? They look so primitive even *I* could have drawn them :>)

Mikdog · Post by **Mikdog** » Tue Feb 24, 2009 2:51 pm

I vote for non-interpolated mouth positions. They look better AND they're easier to animate. I've used both before, and I find non-interpolated mouths to be snappier, they look a lot less 'messy' than and I find interpolated mouths isn't really noticed anyway. Just a whole lot more work - unnecessary.

slowtiger · Post by **slowtiger** » Tue Feb 24, 2009 2:54 pm

Every live action lip movement is by nature interpolated, but not every cartoon lipsync could. There are even lots of characters where it is completely impossible to interpolate between mouth positions, like this one:

(Werner, handdrawn animation of 1990)

How different are the mouth positions from each other?
How accentuated has the speech to be?
How much overall expression affects the mouth positions?

I found that mostly an over-accentuated speech doesn't fit, instead it's better to have not so different mouth positions, but not interpolated (to compensate for the lack of distinction). Only in a very agitated dialogue where certain syllables get stressed for emotions interpolation makes sense, but only for the accents (like at the end of a "says whoooo?", where the "who" is played out quite slowly).

heyvern · Post by **heyvern** » Tue Feb 24, 2009 3:04 pm

I, of all people using AS, have been leaning towards "non interpolated" lip sync. Not specifically for the "floating teeth" reason but mostly due to time issues.

Creating a set of phonemes that interpolate well is ten times harder and more time consuming. Getting the points right is only the first hurdle, then you have to adjust things to they "morph" or interpolate correctly. You have to make sure things like the tongue and teeth will "hide themselves" correctly without looking strange (floating teeth for example). And then of course you have the example that Slowtiger posted. How the heck do you handle that?

Ages ago I did about 8-10 minutes of solid dialog and lip sync using switch layers and papagayo. I painstakingly made it all "interpolated". It looked good. I liked it... but MAN it was a pain. I had upper and lower teeth, and a tongue. I had to check every combination of interpolation for each layer to make sure nothing weird was happening and then tweak it it it did.

It would have taken a fraction of the time to create the phonemes if I eliminated the interpolation. and due to the fast dialog no one but me would have noticed a real difference.

-vern

mkelley · Post by **mkelley** » Tue Feb 24, 2009 3:12 pm

Thanks, guys, for the info (and it all makes a lot more sense to me now).

I think Vern your explanation makes the most sense which is, namely, that you can do interpolation but only with a lot more work to avoid issues. There's no question that with my series schedule I ain't gonna do anything that creates *more* work <bg>.

I only wish I had thought to ask this a year ago -- oh well, it's always better to *improve*, isn't it?

heyvern · Post by **heyvern** » Tue Feb 24, 2009 3:40 pm

Don't forget you can always go in and do more with a specific section of dialog if needed. For instance a long drawn out word or phrase could be handled in a different way from the rest of the lip sync, using point motion or interpolated switching.

-vern

Mark Bremmer · Post by **Mark Bremmer** » Wed Feb 25, 2009 9:50 am

It's definitely a speed in production thing.

It's not uncommon to have non-interpolated for standard dialog but period interpolated segments for extreme close-ups, parodies of slow motion film or overstated emotion. But these interpolated segments are usually just a few seconds long.

DK · Post by DK » Wed Feb 25, 2009 1:13 pm

It depends entirely on the dialogue and direction. A slow drawn out section of dialogue like "Whaaaaaaat?" would look wrong if you used non interpolated mouth positions. Personally I use a mix of the two for both eyes and mouth.

Cheers
D.K