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James Roth
Silhouette Questions
on Apr 12, 2017 at 5:33:47 am
Last Edited By James Roth on Apr 12, 2017 at 5:53:58 am

Hi everyone, I'm working with silhouette footage, created through a) shooting a model against green screen and then b) taking the chroma-keyed model, crushing the colors down to pure black, then tinting it with a solid color to create this:



I have a few questions that maybe people on here can help me with.

#1. HOW TO MOTION TRACK BACKGROUND ELEMENTS TO THE SILHOUETTE
I want to motion track lens flare, background objects (like skyscrapers) and 3D text so that it matches the camera's movements. I am working with shots where I have the camera pointing at the model's feet and then quickly dolly up to her head, like this...



What's the best way to track the lens flare and background elements so that they match the camera's quick zip up to her head? Since the footage is keyed the model has no background whatsoever - just an alpha channel.

#2. HOW TO ADD GROUNDING SHADOWS
Referencing the above image, what's the best way to go about getting a Global Illumination/Grounding Shadows look on the white floor? I know you can flip her upside down, turn the color black/blue, and then use a gaussian blur to make it shadow-like, but I'm looking for something a bit more professional, like this:



What's the best way to get that look in After Effects?

#3. HOW TO SHARPEN HAIR AND ELIMINATE SHADOW NOISE
This is my worst case of bad hair-keying (this was actually shot against a white backdrop so it's not technically proper color-key). This is the best I can get the hair to look without bringing in background noise (the noise appears anyway in the bottom-left). I've cropped it the best I can but noise still slips through and the hair still looks matted and fuzzy. Any FX I can use to get rid of that grainy background shadow that appears underneath the model's feet as shown in the above picture of the model's legs?



Bonus Question: Keylight crashes in After Effects when keying this 6K footage. I've done my keying using Ultra Key in Premiere Pro, is this comparable to Keylight in terms of getting a professional-looking key? How should I convert the 6K footage so I can key it in AE without Keylight instantly crashing? My system isn't bad (i7, GeForce 960, 24 gigs of DDR4). TIFF sequences take forever to export out of Premiere Pro and for some reason exporting in H.264 washes out the colors; which doesn't matter since I'm going to crush the colors anyway but I don't want any loss of edge fidelity at all because it REALLY shows with silhouettes. For some reason the white background turns pink/gray after exporting to H.264 as you can see in the images above. I did a screencap and the background is 100% white before export, and then turns pink/gray after export and I can write my name on it in white brushstrokes. Why is this?

Thanks guys!


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Richard Garabedain
Re: Silhouette Questions
on Apr 12, 2017 at 4:15:41 pm

6k..wow..good luck...but you could use track camera , and then have a duplicate of her being silhouetted on top...

Shadows are tricky with green screen footage...even hollywood movies have a tough time with this..but a tinted copy of vc reflect can do a decent job if you play with the settings...you could also turn the layer 3d add a light that casts a shadow on ground plane.

Bonus question,...You should key the footage, then pre render out a png sequecne with alhpa and import that back in and then do your effects on that.


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Dave LaRonde
Re: Silhouette Questions
on Apr 12, 2017 at 4:35:04 pm
Last Edited By Dave LaRonde on Apr 12, 2017 at 4:47:37 pm

I think you need to solve your AE issues with Keylight, and do the whole thing in AE.
This isn't the first instance of Keylight crashing AE CC 2017 -- which I presume you're using.

A quick search on Adobe's AE user-to-user forum might get AE working properly.
https://forums.adobe.com/community/aftereffects_general_discussion/content?...


[James Roth] " #1. HOW TO MOTION TRACK BACKGROUND ELEMENTS TO THE SILHOUETTE"

Hopefully, you put tracking markers on the green screen in a slightly-different green than the whole background. That way, you can do the tracking and still pull the key. If you didn't, you've got some hand work to do.
May we additionally assume that you took great pains to shoot a properly-lit, properly-set-up chroma key to give yourself the best chance of success? It would be a shame to shoot in 6K and work with just a wrinkly ol' green bedsheet and a couple of borrowed lights.



[James Roth] "#2. HOW TO ADD GROUNDING SHADOWS"

For something that simple, an animated mask would do to make a shadow. Pretty easy.


[James Roth] "#3. HOW TO SHARPEN HAIR AND ELIMINATE SHADOW NOISE"

This is why you should pull the key in AE. Keylight's good, and you have additional tools like Refine Matte, which help with details like hair.




[James Roth] "Bonus Question: Keylight crashes in After Effects when keying this 6K footage."

Go get your software issues resolved, as mentioned above.
In addition, you might want to look at transcoding this footage to an image sequence perhaps, or to a high-quality codec -- one that doesn't have the bejeezus compressed out of it.

Dave LaRonde
Promotion Producer
KGAN (CBS) & KFXA (Fox) Cedar Rapids, IA


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James Roth
Re: Silhouette Questions
on Apr 12, 2017 at 10:48:01 pm

Thanks for the replies guys!

DAVE: "May we additionally assume that you took great pains to shoot a properly-lit, properly-set-up chroma key to give yourself the best chance of success? It would be a shame to shoot in 6K and work with just a wrinkly ol' green bedsheet and a couple of borrowed lights."



Yes, the green screen portion is not really the issue. I have taken all the steps to fix Keylight in AE including talking with Adobe customer support, rolling back to previous versions of After Effects, fiddling with GPU settings, etc. I think my system just crashes because it's 6K. Exporting it as a still image sequence out of Premiere Pro takes eons. What I want to know is if there's a way to convert the 6K so that it doesn't crash After Effects and retains 6K quality; this is because I can easily zoom in the 6K and retain the quality. I've keyed using Keylight before, it's this RED footage that Keylight doesn't like. If I export it as a TIFF or PNG sequence, won't I lose the ability to zoom in and retain complete fidelity? I could just zoom in beforehand in Premiere and hope I don't cut too much footage of her walking close to the sides of the frame. I quickly realized I should have put Hollywood-style tracking markers on the green screen but hindsight is 20/20 I guess. Maybe on the next shoot.

DAVE: "For something that simple, an animated mask would do to make a shadow. Pretty easy."

How exactly? Masking out a spot shadow under the model's feet and tracking it across the frame? Maybe I'm missing something but I can't see that looking that great, especially on shots like the mode's feet where she's walking and I'd have to match two shadows to each foot as she walks.

DAVE: "This is why you should pull the key in AE. Keylight's good, and you have additional tools like Refine Matte, which help with details like hair."

Premiere Pro's Ultra Key has about sliders to refine the Transparency, Highlight, Shadow, Choke, Midpoint, etc. I'd definitely love to get Keylight working but in the meantime how should I handle my workflow? Key in Premiere, zoom it in for max scale, and export as TIFF sequence? That would take days of nonstop rendering with all the footage I shot. I could export as H.264, but I just want to make sure I'm not messing with the quality since this footage is going through AE a few times and then back into Premiere for the final edit; I don't want all that shuttling to result in a loss of quality, esp. seeing as exporting this 6K footage is resulting in darkened whites and washed out colors as shown above.

What is VC reflect? I'm also not familiar with what Richard means when he says to duplicate the silhouette and use Track Camera on top. What I'm really interested in is finding a way to eliminate that grainy shadow that occurs under the model's shoes as she walks; the green screen just gets too dark to key it out properly and short of having tiny gnomes with lights under her shoes on the next shoot I'm not sure how to clean up those shadows without destroying some other part of the silhouette (like the hair) with aggressive use of the sliders.


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Daniel Waldron
Re: Silhouette Questions
on Apr 13, 2017 at 4:02:31 pm

Don't make H264s. That will lower your quality and make working in AE a nightmare. Make ProRes or DNxHD files to work with if you can.

VC Reflect is a free plugin for reflections that you could potentially re-purpose for shadows.


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Dave LaRonde
Re: Silhouette Questions
on Apr 13, 2017 at 4:12:42 pm

[James Roth] "...in the meantime how should I handle my workflow? Key in Premiere, zoom it in for max scale, and export as TIFF sequence? That would take days of nonstop rendering with all the footage I shot."

It sounds like it's time for some choices to be made in PP. I'd select ONLY the green screen stuff I knew I was going to use... with trim handles. I'd cut at 6K in a custom PP timeline. Once I have my shots, I'd export them as PNG sequences. In 6K, of course.



[James Roth] "What is VC reflect?"

I'm pretty sure it's a plugin that easily creates reflections. In your animated shadow example, I overlooked the subtle reflections in the shadow. I'm sure that's why it was mentioned.

By the way, how much of this project is green screen? What's the estimated running time when finished?

Dave LaRonde
Promotion Producer
KGAN (CBS) & KFXA (Fox) Cedar Rapids, IA


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James Roth
Re: Silhouette Questions
on Apr 13, 2017 at 10:31:22 pm

DAVE: "By the way, how much of this project is green screen? What's the estimated running time when finished?"

This project is 1 hour long. 20 minutes of it features silhouettes walking around interacting w/ titles, animations, gesturing, emoting, etc. Another 20 minutes of it is 3D animation made in the same art style (big red 3D letters, 3D skyscrapers in red). Another 20 minutes of it is simple filler animations (2D text in 3D space and the like). The silhouettes are mainly used in this type of stark red/white art style, I'm focusing on setting up some killer animations to make the whole thing pop.



This shoot was a test for the real shoot w/ a professional model. I'm considering backlighting the model this time for extra fidelity, lighting the cyc wall better to eliminate shadows and noise, and using tracking markers. This is all shot in slo-mo.

My #1 concern at this point is...

SHADOWS!
Getting great-looking shadows and/or reflections is really crucial to grounding the silhouettes in the whiteroom and making sure the art style is "minimalist," not just "plain." I've downloaded and used VC Reflect and it works great, but due to how reflections actually work, the model's feet are spaced apart on the Z axis in real life, which VC reflect doesn't mimic since all it does is flip the 2D footage. Her feet and the "shadow feet" have a lot of problems joining up when she walks from the side, when she spins on her heels, etc. (Look at the last image to get an idea of how reflections would be tricky). I'm really using the skew and angle features in VC reflect to the max, but even keyframing the shadow angle/skew angle so the feet always meet up with her shadow mid-walk ends up in a very unnatural and wobbly looking reflection. Add in perspective shots like looking down on the models feet at a 45-degree angle and it gets really tricky, really fast. If someone here could suggest a way to create this look, or something similar, I would be forever grateful.



Plain moving disc shadows (animated masks and/or blurred shape layers) aren't really cutting it, especially when she walks, because her legs/feet don't affect that type of shadow. As you can see, the above shadows are "reactive," that is, the ground shadow darkens when feet move over it. Coupled with the reflect this really sells the 2D/3D hybrid look on an otherwise plain 2D silhouette.

Any suggestions on how to eliminate the green-screen noise that accumulates by the model's shoes is also greatly appreciated. Since her shoes are touching the green screen directly, I end up with black areas that inevitably end up as grain in the final key. An even bigger problem is spot shadows appearing between her shoes as she walks, as the studio shadows criss-cross one another. Any effect or adjustment I could make to eliminate this would be great. And also, why the heck does exporting to H.264 make my whites and reds so dark (also shown below).



Thanks guys!


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