Random black dots occasionally appear on render

[gracelorn]

The scene is a simple room with a portal in the window, a daylight system with Corona sun in it, and Corona Sky in the environment slot.
Sometimes these black dots appear which don't go away no matter how many passes I wait. Then, when I re-render the scene they are gone. Then appear again.
Also, for some reason they turned out white when I saved the image. So I made a scheenshot to show how they looked.

Build 2014/01/16

[gracelorn]

I think it had something to do with Arch&Design material in the scene. When I replaced it with Corona material, the problem was solved.

[Ondra]

Can you upload the scene (the one with the arch&design materials)?

[gracelorn]

Done.

https://www.dropbox.com/sh/s7iuy8etng9wspa/255k3mhqAY

[Ondra]

fixed

[Rimas]

Sorry for reviving an old topic, but I am getting the same issue... Weirdly enough, my Xeon workstation renders everything clearly, but my i7 PC gives me the following results in the sequence:






Pretty sure I shouldn't have any MR materials in my scene as all are fresh imports made for corona, but I'll double-check. Really weird!
This is on Corona 1.3

[maru]

Can you send this scene to our support? https://coronarenderer.freshdesk.com/support/tickets/new

[Rimas]

Will do when I have some spare time later today! Need to get a job out the door first :/

[Rimas]

Hi, Maru!

I sorted it out! Seems like the issue was that I created the file on my Xeon workstation with Corona 1.3 and then offloaded it to render on a network PC that had an older Corona version (1.2.1)... I've updated the PC to 1.3 and it works fine now :)

[maru]

Sounds plausible.
Btw I remember similar issues with displacement and Siger plugins.