Animate small part of the scene

[zegamez]

Hello, guys! I need to animate only a small part of the scene. Is it possible to do this without rendering the whole scene in each frame?
The idea is to add a series of images of the scene's part over the whole scene in Sony Vegas.

 

[zegamez]

If you have a static camera, this is not so hard. But, if your camera moves, then you need to export camera motion data into After Effects or some tools like that.

Yes, but how exactly? I don't want to do Spot Render on each frame

 

[mickydoo]

If you google Daz canvas it may work, I have never tried it with an animation and canvases have their own issues at the best of time. The only other way is to add an affect in after affects if you had it, buy that is a whole other mission. I personally would go the spot render route, 10 frames, 100 interactions with the denoiser and loop it in movie software.

 

[zegamez]

Thank you for answering! Canvas doesn't work for my needs. Spot render route is exactly what I what to avoid.

What I am asking about is:
I have a scene, say, a forest with a lot of objects like trees, grass, etc. My character, for example, is dancing in the right lower quadrant. Camera doesn't move. I want to render the whole scene 1920 x 1080 without my character just one time, and then render 200 frames of the right lower quadrant 400x400.

 

[mickydoo]

Thank you for answering! Canvas doesn't work for my needs. Spot render route is exactly what I what to avoid.

What I am asking about is:
I have a scene, say, a forest with a lot of objects like trees, grass, etc. My character, for example, is dancing in the right lower quadrant. Camera doesn't move. I want to render the whole scene 1920 x 1080 without my character just one time, and then render 200 frames of the right lower quadrant 400x400.

Ok, I'd do this, if I didn't already know it wouldn't work as I use an old version of premier pro.

Render the scene like you say at 1920 x 1080 without the character. But then render the animation at the same 1920 x 1080 resolution for the desired frames and save it as an image sequence in .png format. At the same resolution means it will sit at the exact spot on the main image. it still wouldn't take long as there is nothing else to render. The reason it wont work for me as premier pro doesn't support transparency like photoshop does. I have no idea if vegas does its been years since I have used it.

 

[osanaiko]

Ok, I'd do this, if I didn't already know it wouldn't work as I use an old version of premier pro.

Render the scene like you say at 1920 x 1080 without the character. But then render the animation at the same 1920 x 1080 resolution for the desired frames and save it as an image sequence in .png format. At the same resolution means it will sit at the exact spot on the main image. it still wouldn't take long as there is nothing else to render. The reason it wont work for me as premier pro doesn't support transparency like photoshop does. I have no idea if vegas does its been years since I have used it.

FFmpeg is the tool you need.

1. Render twice - background only as still image, then dancing figure as animation (or series of stills that you combine into a video if you prefer more control over the video encoding). Use a flat single color for the background of the dancing animation, one that does not appear in the dancing figure.

2. use ffmpeg to layer the dancing animation over the still image. you can set the flat background color to be treated as transparent. The exact command line to do this you will need to research and discover yourself, however this article discusses the thing you want to do:

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[zegamez]

Thank you everybody!

Rendering the character separately from the scene does work. Making 60 1920x1080-frames takes only one hour in my settings (1000 samples per frame).
Assembling the whole scene in Sony Vegas is super easy and hardly takes 2 minutes.
The only problem is the absence of the character's shadow.