Weird material behavior when using Backplates

[moadr]

Hello!

As far as I remember this bug was existing also a long time ago in Corona, but I think in previous versions (1.4 for example) the behavior was not that bad. After installing 1.5, unfortunately it got worse and now we have this problem almost all the time. I have attached a crop where you can see the problem:

Light behavior when the backplate is active


Light behavior when the backplate is hidden


In the wood material I removed all the details, it is just a diffuse map and a glossiness value. When the glossiness value is 1.0, or close to it, than there is no problem, but once I start to lower it just a bit (around 0.8) the artifacts appear. The backplate is set up as it should be, I get the same results with the rayswitch material and with the coronalight material also.

I remember that previously this problem appeared mainly in interior scenes when the thin option was not enabled on the window glass materials. Now this problem occurs almost all the time :/

[shadowman]

already was mentioned
still the same behaviour
https://forum.corona-renderer.com/index.php/topic,13860.0.html

[moadr]

I don't have the chance unfortunately now to try it out, but in previous versions I think the behavior was different. Before we only encountered this problem a couple of times where we managed to find a workaround. Now this problem appears in almost every single project which is quite a big issue (especially that we are talking about just simply using a backplate in the scene which is mapped on a cylinder). But thanks for letting me know about the other topic, I will also keep an eye on that.

[Ondra]

file received: 1503-03-HOE-i-05_Hus-C_Apt-163_image_bluehour.zip