Animate just part of a frame?

Deke

If I have a wide locked-down shot, with just some characters moving in a corner, is there a way to save on render time and just render the one corner of the shot? I could use a still frame to complete the shot.

WendyLuvsCatz

crop it to the action and render that I suppose then add those frames as layers to the big one in a photo or movie editor?
next time just render the background and and add the figures after!

Deke

Thanks. I tried cropping the frame in the render settings, but it would always crop from the center of the frame…so it wasn't possible to take, for instance, the left side of a 16;9 frame…just the center. And if I render just the character, then I get no shadows on the floor. I really like to know how to render a figure and it's shadow separately.

Steve K

dkutzera said:

... And if I render just the character, then I get no shadows on the floor. ...

I'm not sure what program you're using, if its DS I don't use it. But in Carrara, I often use a complex environment render, e.g. a complex building front with sidewalk, as a background, then render an animated character using "shadow catchers". These are one or more primitives that roughly match the background shapes, but only render the shadows that hit them. It can save a LOT of render time.

Richard Haseltine

Try using some plane primitives to create a mask - they will still have to render, but they should render quickly. make them a contrasting colour to your scene elements and set their ambient colour to white/ambient strength to 100% so they are uniform and so easier to select. For a single frame you can also use the Spot render tool, setting it to render in a new window via the Tool Settings pane.

Deke

I'm using Daz Studio 4.6. I wonder if there are shadow catchers for it. I'll definitely look that up. Thanks for the tip.

WendyLuvsCatz

for shadowcatch there are a few options free and paid

free
use shadermixer unfortunately cannot get to forum archive to show tutorial http://forumarchive.daz3d.com/viewtopic.php?t=116187
how to use shadermixer is here http://www.daz3d.com/forums/discussion/25448/
someone has a noncommercial use only one on sharecg

paid
PW catch is good I hear http://www.daz3d.com/pwcatch
I use DimensionTheory skies of Terra or Yosemite park HDRI scenes which have included shadowcatch planes
http://www.daz3d.com/hdr-prosets-yosemite-pack-one

Steve K

wendy♥catz said:

... I use DimensionTheory skies of Terra or Yosemite park HDRI scenes which have included shadowcatch planes
http://www.daz3d.com/hdr-prosets-yosemite-pack-one

I also have that product but haven't tried it yet. It appears the included shadow catch feature is only for DS and Poser? The product has a Carrara version but that does not show the included shadow catch feature, for some reason.

Deke

I suppose another way to tackle this is to strip the set of all materials? Would that just result in a shadow?

BC Rice

If I'm getting your question correctly, you're wanting to just render a couple of characters in a scene?

I'll tell you what -- I only ever render animations as PNG sequences. I don't think I've ever rendered an animated background. I approach all animation like traditional animation with a flat background render and then put the animations on top of that.

So that would be my advice. Render the characters as a PNG sequence (with the rest of the scene deleted, alpha matte only) and then just plop them on top of it.

Deke

Thanks. I can get away with that technique some of the time, but I'm after a more CG look with a camera that moves through the 3D set. That's why I was after a way to render the shadows falling over the set. Part of it is resolution. To save on render time I like to render the character full resolution and the background at lower resolution. But separating them means I don't get the shadows.

BC Rice

Yeah, that's tough. I never use (character) shadows out of Carrara/DAZ. I always throw them in in AE cause it's faster -- though completely dirty quick.

Wondering if maybe your whole low-res approach might help? Like if you rendered the whole thing (including characters) at just ridiculously low levels just to get the shadows and then render your PNG sequence actors at full res and then your background at some mid point and then just overlay the low res shadow layer? Though an overlay function would at the very least require PS or AE or something in that realm I think.

Top layer: Character hi-res PNG sequence
Middle layer: Characters and background/low res render set @ overlay
Bottom layer: Background render

I know there's a "real" way to do it and that would be like following this sort of tutorial.

https://www.youtube.com/watch?v=7UsgnU140tw

Or, alternatively, you can just make it so that it's noon...or the lamp is over their head. haha ;)

Deke

Yes…tough…but some amazing results are possible. I chuckle at the high noon idea. Seems to me that most of the animations I've seen done ocurr at high noon…and the characters seem to float on the background.

How does rendering as a series of stills impact the work flow. I tried one shot and got that resulting list of JPG. How is that then brought into an image editor or effect program like AE or Premiere?

DUDU

The most realistic renders of the shadows is all the same that which is done in Carrara.
It takes into account the surrounding of 3d objects.
A sequence of image is imported in AE in block and you work as with a normal footage.
Select the first image and import as footage.

BC Rice

dkutzera said:

Yes…tough…but some amazing results are possible. I chuckle at the high noon idea. Seems to me that most of the animations I've seen done ocurr at high noon…and the characters seem to float on the background.

How does rendering as a series of stills impact the work flow. I tried one shot and got that resulting list of JPG. How is that then brought into an image editor or effect program like AE or Premiere?

You don't want to use JPEG (ever, hopefully). You'll want to use a sequenced PNG and only render the alpha matte.