strange dirty splotches!!!!!

[blackmug]

Hey guys... i have some problems with splotches on a side of a wall which is in the shadow... the settings are very high..
BF 30
LC 5000, sample size 0,001
noise treshold 0,001

DMC sampler 4 16
catmull...
vraz sun+vray cam...

i tried with different settings and the problem stays..

the wall is made of geometry (not displacement) with vertical grid.. like concrete blocks with vertical panels..

everything look ok, but this vertical grid wall...

[RE:FORM_STUDIOS]

what are all your qmc settings, and lighcache filtering?

[blackmug]

LC filter nearest. with interp samples 10..

dmc sampler... adaptive amount 1,0
min samples 4
noise treshold 0,001

[3DMK]

Had the same problem on a recent job with very fine/detailed geometry.

Considering your very detailed LC settings [.001 is a bit over-kill I think, you shouldn't need to go past .005 in most cases] you may need to go much higher with LC subdivisions...possibly up to 10,000 or more to get a clean enough solution. Try rendering that part with just the LC as first & second bounce to see how clean the LC solution is.
In the end you may need to render separately that wall with Brute force as primary & secondary bounce to capture the detail cleanly.
Try a test render with just Brute Force & you will see that it is perfect for this type of fine details.
If computers were fast enough [or if I had enough of them] I would use Brute Force for all my renders as it captures the small details & lighting so much better than anything else. It's the ultimate GI solution, only problem is it's too F?*$ing SLOW to use [as both primary & secondary bounce] unless absolutely necessary.

Cheers

[blackmug]

heyyy... i have rendered it this afternoon with BF + BF .. and it looks amazingly correct... the render time is 2 hours (which is ok), and this long .. even longer render time i get with most higher settings with LC and IM... so BF+BF rules.. its slow but solved my problem...

thanks anyway!!