Below is a render of a recurring problem i have been having which most likely has a simple solution that i just have not found yet.
What parameters do you think i would need to adjust to get less of this “dirty” effect? If you need to see some of my parameters, i can get them. Any hints to start me in the right direction would be much appreciated!
:?:
i think you need to post your settings
Here are some of my settings, let me know if you need more.
hi
first of all change your AA settings to Adaptive (0_3)
increase your Interp Sample to around 45 +
change your Direct computation settings to Subdivs = 10 Depth = 30
in the vray advanced irradiance map parameters make sure you have , check sample visability ticked.
and that should do it.
post it when your finnished
Looks like it is going to take a while to render, but i will post the results as soon as i can after it is done.
So much workflow here leaves me so little time to learn what all of these settings do. Thanks so much for your help natty!
your welcome
I thik the most important thing I found to work well in those situations and in light leaks in general - is to check the “check sample visibility” checked before upping all the other settings - that ususally did the trick alone…
but than again every situation is different…
I would try each one of those things addictivly testing - instead of just upping every thing at once and get your render times through the roof…
paul.
Looks like it might be a smoothing issue to me. I’ve noticed that when using Vray displacement, if it’s a flat object that has smoothing groups applied, it renders just like you see. It looks like it has been burned or blackened. Try removing your smoothing groups.
John Pruden
Digital-X
You are correct, the render times have went through the roof and beyond. I can justify it, though, because the client was complaining about that particular flaw, and i told him that it would take an extra amount of time to sort the problem out. :roll:
I think i will go back to my other settings where it was taking a total of 45 minutes to calculate the irr. map and render instead of 5 hours. First I will see if the check sample visibility will fix it, then I will slowly increase the recommended settings until it fixes the problem.
Sorry that I cannot show any more of the building than that, my largest client is very touchy about disclosure, but i will post an update of that area once i am done or get stuck again. 
Thanks guys! 
P.S. About the smoothing. I do not think that would be the problem since the CMU wall behind the metal roof continues down a ways past there. However, if none of these other things work i will surely try that out.
I found out what the problem was, but i never got a chance to re-render with the changes. I had the amount on my bump map set too high.
I also found that VRay does not like it when i check the “check sample visibility” box when i have displacement in the scene, it shoots the render time through the roof.