Interior animation workflow, LC and IR?

[m_hinks]

I posted about this on another thread but has been forgotten over time so here it is again!

I have been rendering out very large stills from an interior scene, a London tube station, and have been using IR (High preset base but with Hsph 120, interp samples 40, -5, -2 passes) and Light cache (650, size 0.04 screen, interp samples 20). The render times are high but the results are spot on.

However, I am now charged with the task of producing a 3 minute animation, a single cam walkthrough of the station from above ground, through the station, and in to the platform. The cams pretty much set up and Ive been doing some test render over the weekend. I have a lot of glossys and 60+ lights. Ive been trying with AA fixed 2, and seems to get not bad results but 3 would be best. I've Now settled on using Adaptive Sub 0,2 and getting good results.

My main concern is with the lighting. I realise I need to change from screen to world for LC, but the workflow to pre calc the LC and IR for a single cam 3 minute path is my problem!

Could someone explain the correct method. I am assuming I need to maybe work out the LC first on walkthought mode, with a load of samples, then save it, and use to the pre calc the IR, every 25th frameish?

However after reading other threads, should I be setting the LC as is, and just pre calc the IR, then load the IR and turn off the secondary?

Id be very gratfull for help in this.

Thanks

[glyph]

set LC to walkthrough (600 maybe too low for walkthrough)
IR on incremental,
then render every 25th or so - 15 might be better (depends how fast your camera moves - enough to make sure you've got plenty of coverage)

render output off
save both LC and IR maps
depending how your lights are set you may only need to load the IR map to render (as LC may be stored with IR)

on a test version, limit the animation time to five seconds so LC walkthrough calc will be quick (as it will calc the entire visible scene) and do a dry run !

it does still work if LC is set to screen

[m_hinks]

Thanks Glyph,

With doing a shorter 150 frames test, would the quality of the LC, say 1000 samples, be the same as when its doing 3000 frames?

[glyph]

ah no, i dont think so - the samples are spread over the viewable area of the animation so depends on camera speed through the scene - I reckon you'll have to make a rough guess - but it doesnt need to go up by as much as you might think as its a squared value (1000 =1million, 2000 = 4 million)

[m_hinks]

I've since split the cam path in to 4 sections, and removed, lights, geom that's not visible or effecting the scene, try to speed up the renders.

So Ive now got 4 separate paths to work out the lighting for. I think this will help a bit.

[m_hinks]

So, ive tested an option now, Precalc the IR every 25th, with LC on normal, every frame. I then turned off secondary and rendered the sequence, and the light is correct just a but low on samples.

Is this method a correct one to use. I understand the best way is to precalc the LC with walkthrough first then precalc IR, but this seems to be working?

Any ideas.

[glyph]

I think someone else should help out m hinks here - LC flythrough has always worked for me, done at same time as IR - even if IR render is set to every 25th frame, the LC flythrough will do the entire animation length - seems to me you're over complicating it a bit

the removal of bits that dont affect the scene will help a little, especially if ram is a problem, but I've done that before and the speed gain wasn't a lot

it can all get complicated with multiple scenes and if the client wants a change its not so easy!

[m_hinks]

I am going to try the "correct" method now!! Light cache for both primary and secondary, flythrough mode, about 1000 samples to start with. Then save and load in , and multiframe the IR using loaded LC. The turn off LC and use the loaded IR.

The problem I am having is getting the right amount of samples for the LC, and the right world scale for size. I am rendering the results with fixed 1, for get quick feedback. I wonder if there is a way by looking at the IR file and seeing if its good enought before rendering?

[glyph]

hot damn - dont do LC for primary and secondary - as I said IR primary and LC secondary
render the lot together, every 20th frame, IR set to add, LC set to flythrough - end of story

render a test frame to see if its good

there's the ir map viewer but unless you really know what you are looking for it just makes for fun viewing

[m_hinks]

I have been getting good results now all day with my method. The only thing I am doing different to you is working out the LC once on fly through then loading it in, instead of your way doing it at the same time as IR. Surely your way you end up rendering the LC every 20th frame?

[percydaman]

no you dont. because the ir map/LC method requires you to calculate the LC on flythrough. Your method most likely just ends up being the same in the final output as the other method.