IR/LC flythrough big exterior settings

[Erik N]

I am in need of a good workflow. Scenario: Huge exterior scene, 30.000+ meters extents, lots of polys, 750 frames sequence. I want to send all necessary jobs to backbruner and go on a holiday . How to best go about the following: 1) finding good LC settings 2) sending the jobs to backburner in a sensible way.

With 1) I have the following issues:
a) Testing the LC settings for a 750 frame sequence takes for ever. How to test with reasonable rendertimes (say, by testing on a 50 frame sequence) and then "scale" the settings?
b) Should the LC-calculation be set to every frame, every tenth or just to one frame with the timeslider including all frames?
c) Is world scale really the way to go with huge exteriors? How can one understand the relationship between world/screen scale and the length of the sequence?

With 2), this is my best guess:
Job 1: 1.+2. bounce LC. Send to one server only.
Job 2: 2nd bounce from job one (set dependent on job 1 so LC is finished), 1st bounce IR, every 10-15th frame, no final image. Send to one server
Job 3: Final render with saved LC/IR. Send dependent on job2

In general, I am in need of suggestions for a good workflow...

[jujubee]

a) Testing the LC settings for a 750 frame sequence takes for ever. How to test with reasonable rendertimes (say, by testing on a 50 frame sequence) and then "scale" the settings?

That shouldn't take that long. Don't use world scale - it's the one thing I feel is wrong with the tutorial.

[tammo]

lighcache: split up the animation. i doesnt work with very long animations.
it worked for me (as secondary GI, primary IR map) with a 1300 frames long animation using 3000 samples resulting in a 100 mb file. quality was "OK" but could be a LOT better if i had split it up.
if you use more samples it will just crash during calculation.

dont use screen mode.
objects that come into view from far away will look ugly because they have huge samples on them.

world scale uses the sample size setting (screen mode doesnt even if its not greyed out). you have to find the sample size by luck, it seems to be different for every scene. there is a tutorial but i didnt understand it.

also disable the pre-something in the LC rollout.

cancel your holiday.

there is no way to do a large animation without trial and error.

[Erik N]

Thanks for the replies. But, hehe,

Don't use world scale

and

dont use screen mode

... I guess this is a matter with no definte solution Anyway, I think I found that world scale is impossible to use on a scene of this size, and for this one job I ended up doing it with QMC secondaries anyway, as I didn't want to cancel my holiday...

Splitting up the animation into shorter sequences though seems like a good tip. I also found you CAN send the LC and IR calculation as one job to backburner, since the flythrough mode only takes into account the number of frames present in the timeslider (for some reason), but the job needs to be done on a single machine (also good for IR quality).