What must i do to reduce noise????

[pedroarq]

I have a dual quad core E5440 2.8, gtx 670 with 3GB, 8gb ram
The image still got noise!!! Why? I see here lot´s of renders done in a few minutes inclusive with this scene

[Ludvik Koutny]

Why? I see here lot´s of renders done in a few minutes inclusive with this scene

Because those renders are done by people who know what they are doing.

Most common things that cause slow renders are:

- Using converted materials from other engine instead of remaking them from scratch
- Using other than progressive integrator, like bidir or VCM
- Using PT as secondary GI for interiors
- Having glass in windows with refraction mode set to solid
- Using geometry around scene to light the scene, instead of putting environment map into environment slot
- Having too high max sample intensity multiplier
- Having too complex curtain material
- Having bitmap paging in 3ds Max asset tracker enabled

[pedroarq]

i´ve switched secondary GI to HD and the scene got green :S

[Ludvik Koutny]

It will stay green only during first pass, until first pass completely replaces pixels of HDcache precalc. phase. This will be resolved in the next build.

[maru]

Looks like your CPU isn't greatest for this kind of renderers.

Also read this to get maximum performance:
http://corona-renderer.com/wiki/performance_debugging

[pedroarq]

but is has 8 nodes (2 quad core xeon) :S

[chilombiano]

Maru is right on this it seems.
I have the same problem with my old xw6600 ( dual E5420 ). Seems to perform really bad for some situations. I haven't get my head around Corona yet but at first look and by checking the stamp on renders posted on the forum  the amount of rays that that setup crunches in any given time seems particulary small :( .. In certian scenes.
I'm getting a 4930k and will keep the dual for backup ( still a fine machine for other things )

[Juraj]

Looks like your CPU isn't greatest for this kind of renderers.

Also read this to get maximum performance:
http://corona-renderer.com/wiki/performance_debugging

Whoa, there is Corona wiki :- O

Hi again Pedro, glad you posted this on forum.

Anyway I would follow of points Rawalanche wrote to you. What I know about this scene from being setup in Vray, it is setup fully for exponential color mapping and FAR from proper LWF.

Almost all albedos are extremely high, he uses RGB255/255/255 for white, same for his diffuse textures. Easiest to get this to regular level is setting Diffuse level at 0.7 for starting point.

The curtain material is indeed very problematic, it's pretty over-complicated and I think features refraction, reflection, translucency and opacity at SAME time. Create a new curtain material from beginning.

[pedroarq]

where do you control exposure in corona?? and do you load hdri in vrayhdri map?

[Juraj]

where do you control exposure in corona?? and do you load hdri in vrayhdri map?

Exposure: Render Settings/Corona Settings/Post processing tab.

I use HDRi inside VrayHDRi, it's comfortable (360rotation and gamma change on fly), and nested inside Max environment (for viewport preview).

[racoonart]

Most common things that cause slow renders are:

- Using converted materials from other engine instead of remaking them from scratch
- Using other than progressive integrator, like bidir or VCM
- ...

Let's call it "blindly using converted materials without some clean-up work". It sounds a bit anti-material-converter-guy-ish in those bold letters :-D

[Ludvik Koutny]

Most common things that cause slow renders are:

- Using converted materials from other engine instead of remaking them from scratch
- Using other than progressive integrator, like bidir or VCM
- ...

Let's call it "blindly using converted materials without some clean-up work". It sounds a bit anti-material-converter-guy-ish in those bold letters :-D

I do not really think people who use corona for the first time will know how to clean up converted materials if the do not know the basic features and rules of corona materials. So i think people should first at least spend some time learning corona and how materials work before they can afford to clean up converted ones ;)

[racoonart]

I share your opinion but unfortunately that's not how people start using corona.
I've already planned to include some "warning" in the script with a checklist of the most important things to do after converting a scene (like refraction modes and albedo and such stuff)

[Ludvik Koutny]

I share your opinion but unfortunately that's not how people start using corona.
I've already planned to include some "warning" in the script with a checklist of the most important things to do after converting a scene (like refraction modes and albedo and such stuff)

There are going to be also a bit more newbie-friendly material defaults in Alpha V6 ;)

[Juraj]

I think the materials that are problematic in Corona were rather close to problematic in Vray as well. (exception being glass, but that's no different from other path tracing engines)
Anyone knowing his way around Vray materials, will have no problems in Corona either.

Problem is people using someone's else scene and materials without knowing how the original author set this up. In case of this Ramon's scene lot of materials are pretty "out of the box" even for Vray. Vray is pretty much forgiving to weird setups.

Corona isn't that unique or different, but there are lot of miracles expected out of it from users who don't know that much about Vray either.

The converter is top, works without problem for me (ok,...I have a qualm with that 999IOR being default instead of 1.6, but that's about it) in almost all cases.