POST parameter: bug or incorrect behaviour?

[Ondra]

ok, post it, this looks like easily fixable bug

[cecofuli]

See the attachments

[Ondra]

ok, I did some experimenting and thinking, and I concluded that the error is not in the way MSI interacts with exposure, but that it is set too low. MSI should be a parameter "how bright are the fireflies permitted to be". But setting it to 10 classifies most of your scene as fireflies (because it is relatively hard scene, lots of indirect lighting). The problem does not happen with rectangular lights, because they make the scene easy (lots of direct lighting). Point the rectangular lights into the ceiling and you will get the same result.

Anyways, because the scene renders fine with high MSI, I think the best solution is to set the default MSI higher

[cecofuli]

Ahh, ok, now I understand.
But, from your point of view:

(*) what is the best setting for the MSI Default values? Because in my scene it was between 200/400.
(*) Are there disadvantages / advantages by using so high values?

Thanks

[Ondra]

It might differ from scene to scene. If 200 works, use 200. I will test later to determine new default

Advantage of high MSI is less bias, disadvantage is more noise, it is simple ;)

[cecofuli]

I did some test and with this scene. Corona is veeery slow  compared to VRay. See the render.

(*) VRay: 1h with noise threshold 0.003 = PERFECT. I can in 30 min with noise threshold 0.005 and the noise is little more, but not too much.  (BF+LC)
(*) Corona: 1h min. so much noise! (PT+HD)

Did I do some error?

[Polymax]

can you share the scene? I want to test the it.

[cecofuli]

It's in the attachment some post above. Ready to Corona. Just hit render

[lacilaci]

hd cache max records 100?

[Ondra]

it is *1000

[cecofuli]

100 cause I remember the old Corona scene and the problem in the ceiling. I'll try with the HD defualt setting. =)

[Polymax]

Standard material for? Why gray enviroment? Floor have a thin geometry!
I have compared the Vray and Corona on a complex interior, with complex lighting:http://forum.corona-renderer.com/index.php/topic,433.0.html
Vray(BF+LC) lost heavily in all parameters.
Corona work fine in this case also!

[cecofuli]

Polymax, nice result!
Standard material because I do this test with VRay and I override with VRay Material. I forgot to override in Corona too
Thin geometry cause Vray don't have problem.
Gray environment because... I don't know, some old setting...
but... can you scare the scene corrected? Thank you so much!
10 min is an incredible time!
Did you use a geometry emitter like in my original scene?
Bacause in VRay I use a VRayLight as a mesh. Corona doesn't have this option and I used a geometry emitters

[Polymax]

Of course, I attach the scene.
I would like to not divert Keymaster just so, he does not have much time for it!
Further, please be careful in their tests, check all parameters! For the Corona is important and thin geometry and enviroment and materials.
Thank you for your understanding!

Yes, I use yours Lightmesh in Corona, but I tessellate her (just in case).

[cecofuli]

Polymax, you are 100%. But with my  test =)  we discovered that the MSI is too low by defaul and in some scenes (both of my scenes) was too low.
Now I try to "study" your scene =) Thanks