Large Image Render (10k) Strips render Color Mismatch

[contaxx]

Hi there,

i got big problem with rendering a 10k image for archvis!

because i run out of memory, I render 14 strips using backburner (on a single machine 16gb ram).
i choose tiff format (32bit), for some reason ".exr" and ".hdr" don't render the elements!? or the colors are extremly burned out... would love to render it as a hdr or exr, but max or backburner can't stitch or save the single strips!? but i read already somewhere that this is a know issue.
but with 32bit tiff its works just fine

anyway the bigger problem is the mismatch of the colors, shadow and reflection!

the render took 8h with relative low settings:

ir: preset low
lc: subdivs: 500 (ok this is really low) the others are standard

domelight: hdri 16subdiv
sunlight (size multi: 5)


I assume the problem could be:
- i forgot to turn of vignetting
- read something about, that bruteforce will be better as secondary for this reason?
- found this in a different forum "disable interpolation on reflections / refractions in your VRay materials! This causes color issues in DR buckets"
- rendersettings to low for ir and lc?
- god has a bad day and does not like me any more?

i' rendering at the moment without vignetting, so stay tuned

does the resolution matter?? because i was rendering it at 1000px and i didn't see this strips... but i'm not sure about that!

it seems to be stronger at materials with glossy reflections...

if you have a better way to render this kind of high res (10k) i'm really looking to find a better working workflow than mine

all the best
Philipp

[Dariusz Makowski (Dadal)]

What did u render it on? This would take me 20 min to render on my xeon o.o

[contaxx]

hi dadal,
on a i7 3600i 4 core at 4,3ghz.
the resolution is 10000x5630

I have alot of grass and some trees, this was just a closeup. the grass is done with multiscatter, and the 8 trees (3 different kinds) are proxies.
3d max tells me i have 675.000 polys ( i think the grass and trees a excluded becuase of mutliscatter and proxies)
the archmodel comes out of revit ( maybe a bit complex).

how do you render this kind of large image? could you please tell me your rendersettings and domelight setup?
pretty much of my settings are standard, bucket size was 48...

[contaxx]

just found this http://area.autodesk.com/blogs/maxst...e_final_gather

same issue just with mental ray.

what would be the corresponding in vray?

Multiframe incremental?
or
incremental add to current map?

[vlado]

The solution is to render the irradiance map in a first pass (using DR if you wish), save it, and then reuse the saved map for the final rendering.

Best regards,
Blado

[contaxx]

dear baldo,

what do you mean exactly with

render the irradiance map in a first pass (using DR if you wish), save it, and then reuse the saved map for the final rendering.

render the entire frame at once (no strips)? so my setup up would be "Don't render final image" checked?
and just turn primary bounce on?
and than in the second rendering with strips, i choose the irmap-file and turn bf for secondary bounce on?

or should both be on in the first rendering?

sorry for this stupid questions, just want to get it right

will this not also block all my memory?

[Dariusz Makowski (Dadal)]

Disable all render passes
Tick on Dont Render final image
Use IRR + LC
Save them both to files in their settings
When thats finish send scene to BB but tell IRR + LC to load data from file.

[contaxx]

hi dadal,

ok i'll try this next.

here is what I got out of the "Incremental add to Current map" solution. looks surprisingly good


at some small areas its slightly visible, i'll try with 5% overlap next.
But i'm keen to try your workflow, i'll post the result so we can compare

just for documentation to see later one the different (this is not the final rendersetup!)
Vray:
first bounce: ir settings low ("Incremental add to Current map" = On)
second bounce: bf 8subs / 3 bounces (for final render LC will be used!)

Backburner: 2% overlap / 14 slices

this is just a test for the 2%overlap version!

all the best
philipp

[Dariusz Makowski (Dadal)]

U still doing it wrong. And Brute Force is the LONGEST GI you could have picked.

Dont do incremental add, just save to file on HDD and then load that file for BB render... Should I write step by step?

[contaxx]

i know...

i just said

But i'm keen to try your workflow, i'll post the result so we can compare

this is da furture, maybe I should add a "will" or "going to" but my english is not so good
my last post was just the settings of the old image... just for documentation
i was just using Bruteforce, because I thought the lightcache is da problem.
normally i never use it!

at the moment i'm rendering with

1. render ir+lc saving the gi 1st and 2nd bounce -> than final render load the stuff

anyway thanks alot!

[Dariusz Makowski (Dadal)]

Sure thing. Hope you get it to work at the end!

What is ur 1st language?

Thanks, bye.