squares in the shadow/light gradient
what could be the problem?
I made a post processing in Photoshop to lighten the problem. on the original render this bug less noticeable.
It looks like shadow terminator, a disease from which Corona (not exclusively) suffers quite badly: https://coronarenderer.freshdesk.com/support/solutions/articles/5000516258-objects-in-my-rendering-are-not-smooth-faceted-and-i-can-see-shadows-of-polygons-
It should be adressed at least partially in upcomming 1.6 release.
Are you using Normal map?
Give it a test without.
If so, then as an alternative use bump or displacement (depending on the shot).
Pressing random buttons without understanding them is usually the worst thing you can do. Light sample multiplier should have no impact on this issue. It looks like you changed lighting, and that would explain why the problem is gone. Could you share this scene, with the problem visible?
Fstorm just solved this quick and easy. I know Vray has had this solved for years too now, and I know this is a “common” problem, but it has to be fixed. It’s clearly possible, and looks terrible. Hoping 1.6 will do something about, as 1.5.2 has issues.
It is on the list of TODOs for 1.6:
Yes, this is on the TODO list for 1.6. It is also acknowledged since long time ago, but apparently very hard to implement, because basically this is another “fake”.
duplicate - we have multiple reports on this
This is from last year. I’ve kinda lost hope…
FStorm is being developed at crazy paces, we’re considering moving to it at the office and the blasted terminator and the nightmares I’ve been having with it are one of the reasons… (I already moved to it for personal work, I have two GTX 1080 and two GTX 1080Ti in my rig - speed is a major factor too).
This bugfix is still on the list for 1.6 in trello, so fingers crossed…
Last one yet to be checked with RC1 estimated in two days’ time..? I’m not getting my hopes up. It’s such an old problem that it really needed to be solved ages ago. Not knocking the devs, it’s probably hard to tackle with the way the engine is set up, but it’s still been ages. Karba sorted the terminator in FStorm so quickly it’s just ridiculous in comparison…
Interesting how terminator only happens when bump is used and not when it’s turned waaay down or off. Same geometry. I thought a bump map is supposed to add and subtract from the existing normals, similar to a tangent space normal map (whereas a world-space normal would completely overwrite the normals). So how come the terminator appears there? If the lighting model was looking at the geometry exclusively then we’d have the terminator problem ALL of the time, not (almost exclusively in normal usage) when using a bump map… I’m confused here.
What if I tell you that we already have an internal daily build?
So is the terminator solved now?
Yes 
Tested latest daily yesterday, and it’s gone
Praise the lord (Ondra)! O_O
I need to download it. Is it public? I’ve never used dailies.
Yes it is publicly accessible. Go here: Dropbox - Error - Simplify your life download latest exe file and install it like you would with public release. That’s it.
Thanks for this!
What confuses me now is why the standard EXR file autosave was replaced with some proprietary .cxr file…wut?
there are 2 files autosaved, one is .exr, second is .cxr. Even the .cxr is just exr with additional data and you can open it in anything that reads .exr after renaming to .exr. We cannot use .exr directly, because 3dsmax does not allow us saving with any file extension which it also handles
Interesting. But how come EXR worked fine before? I have a folder full of EXR autosaves
Another thing is that for me the daily seems to crash a LOT. I think I tracked it down to the sharpening/blurring in VBF being applied while rendering rather than afterward. No crashes so far when I turned it off.