Friday, January 11, 2008

Rendering and video editing

Following some helpful feedback from the people at Renderosity, I've produced a new version of the introduction to the Flea Circus Film. The depth of field options have been turned on in quick mode (rather than fully raytraced) which unfortunately loses the anti-aliasing on the edges of the case/backdrop but means that each frame renders in approx 4s rather than 3 minutes per frame required for fully raytraced depth of field. The current rendering stats are approx 2 hours to generate 50s of animation which in uncompressed AVI is about 1GB.
The film is in a new size format, it was suggested in 3D world (for the Tin Man film?) to render at 740x405 to get a 16:9 aspect ratio that could be displayed on most screens. I did this but then found that my video editing and conversion tools complained that this was a non standard size. As I was rendering out to uncompressed AVI files and then converting to WMV's for the editing, my solution was to then use the video convertor's letter box feature to resize to 720x576 by adding black bars top and bottom. This allows Premiere elements to be happy when outputting the results whilst also displaying well on my friends' EEE PC which will be used to show off the film at tomorrow's dinner.
There will be some frantic editing tomorrow morning, this intro will be followed by some draft version of the other three acts and hopefully some out-takes will be shown tomorrow evening at the PSTOIC Christmas dinner in South Kensington. Thanks to Youtube, the default picture for this clip is a lovely pink colour.


Unknown said...

I just wondered, aren't you rendering sequenced frames? This gives loads of options after rendering?
It is also nice to have all seperate frames at hand to correct stuff, to extend beginning and starting points (for fading in or out) and it is nice when your computer decides to crash on you, right before frame 224...)

I have used an After Effects filter to create DOF in post, with help of the 'Distance' alpha channel which does not cost a lot of time. There is still some kind of anti-aliasing problem (one can not anti alias between values that are really distant from each other, because that would be considered a gradual kind of thing).
The artifacting of non-aliased alpha channel information can be reduced by rendering at twice the size and reducing it after using the DOF.

If you want to know more, the DOF filter I used is from a German firm, Frischeluft

FleaCircusDirector said...

I have gone with the single frame approach before when producing ratobat (stop motion). However I found that by producing the files as video files and rendering a little longer than needed I get lots of flexibility in the edit.

I've seen a couple of After Effects filters for DOF but so far I don't know of any that work with Premiere Elements and I can't really affort After Effects. Those filters from Frischeluft do look good though.

Thanks for the scaling tip, I've also another technique of rendering the background separately then overlaying but I've not had chance to try that with lots of files. Once I get nearer completion I may add some more computing power to the render so the Raytrace may not be an issue.