Proper Workflow for Shorter Render Times

Jim H wrote on 2/15/2009, 11:03 PM
In another recent post, farss made the comment to the effect that if one uses smart workflow techniques one could shorten the overall render time of a project. Having just failed at that (after 22 hours of rendering I was forced to split my project in two in order to avoid render errors) I wondered if there were any tutorials on just how to set up a proper workflow?

I'm totally self taught through the help of the fine folks on this forum and a lot of trial and error. I'm sure my techniques would make some of you cringe, but I get the job done and have fun doing it. But until I can swing a new i7 computer, I'd like to see if I can do things a bit smarter.

Thanks.

Comments

farss wrote on 2/15/2009, 11:37 PM
There's really no way to avoid the fact that X number of calculations have to be done to produce Y number of frames. How you can avoid the frustration is by not redoing anymore calculations than you have to if you need to make changes.

For example a typical movie has opening and closing titles. The bulk of the movie might be straight cuts. If you do it all in one project then any change to anything causes you to have to rerender all of it including all those calculations needed for the titles which could take more time rendering than the body of the movie.

So you create one project for each of the titles. You can render these out with an alpha channel if they're being composited over video as well. If you have to change your opening titles background you avoid having to rerender all the graphics as well. If you make a change to the body of the movie you don't slow down the render while all the graphics render.

Same goes for along the T/L. If you movie has colour grading and FXs then breaking it down into scenes and rendering each one avoids having to render each scene with all the calculations involved in colour correction.

The other advantage I find of working this way is I'm not living in fear of having a ripple edit foobar my closing titles, less to watch out for on the T/L always helps. Having said that you really should have a plan for your workflow. More than once I've had to go back to an old project and it took quite a while to remember how those intermediate renders were created.

HTH

Bob.
Jim H wrote on 2/16/2009, 9:09 PM
Thanks Bob. When you refer to breaking down the T/L into scenes and rendering each one, what exactly are you doing? Do you create regions around straight cuts (if no straight cuts then what?) Then do you render to the timeline? What render options do you use? Same as the project? or the desired final render format?

On a recent project I had to split it in two parts and stitch them together because I was getting "could not render to media file" (or something like that) errors. The Sony tech told me to render each half and bring the rendered clips into a new project and that "smart renderer" would pop up and advise me that the program wouldn't need to re-render those clips. I never got that message and while it only took an hour to render the 16 min production, it seemed I failed at achieving that aim and the quality suffered another compression.

So I read the manual (wow) and it says that smart render only works for certain file types - not the MP4 HD format I chose for my final render (and for each pre-rendered half). So if my final format wants to be MP4 what's the workflow?