grainy aluminum

[noobert]

It also doesn't help (aaarrrgggghhh), increasing the light sampling subd. up to 40 for each light only makes it a very little bit more smooth (damn! thought that would work),
I really don't know what to do next.

Maybe someone has another clue for this

[percydaman]

Im not sure what else it could be. maybe if you posted the scene or a stripped down version of it. Are you using hdri lighting?

[noobert]

Okay, here is my stripped down scene:
www.ardworx.de/grainy.rar
and the textures if needed:
www.ardworx.de/textures.rar

and here is what it looks like when you hit the render button after opening the scene:

Better than in the image above but still grainy,


it would be great if you would take alook at it!!!
BIG thanx in advance!

[percydaman]

thanks. downloading it now.

[percydaman]

ok without even hitting render, I can tell you that having very high skylight multipliers like the 9x you have is not a good idea. could contribute to it. Also having an irradiance map of -2,-2 is not a hot idea either. You have alot of large flat surfaces that would get plenty of detail at say -4,-2. rendering now, but it seems a bit slow.

[noobert]

thanks. downloading it now.

I have to thank YOU for looking over my scene!

very high skylight multipliers like the 9x you have is not a good idea. could contribute to it. Also having an irradiance map of -2,-2 is not a hot idea either. You have alot of large flat surfaces that would get plenty of detail at say -4,-2. rendering now, but it seems a bit slow.

I've now rendered with skylight at 3x and dark multiplier at 3 and -4/-2 for irridance map like you said but this ******* grain is still there! And yes indeed the rendertimes are terrible, I've decreased reflection subdv. of the alu mat down to 15 but it takes still a lot of time!

[percydaman]

yea ive been able to get rid of the grain, but only if I lose the reflective surface. Also Im not sure, but using the vraylights as portals sometimes contributes to grain. Set them to just straight lights and seemed to help some.

[natty]

i havent downloaded your scene but if i were you i would reset vray and start again... sounds like your settings are all over the place..

[percydaman]

haha you have no idea.

[noobert]

yea ive been able to get rid of the grain, but only if I lose the reflective surface. Also Im not sure, but using the vraylights as portals sometimes contributes to grain. Set them to just straight lights and seemed to help some.

First thank you very much for your quick replies and going trough my scene - really cool!

I know that only the refl. alu material has grain on it. I'll test the light thingy.

i havent downloaded your scene but if i were you i would reset vray and start again... sounds like your settings are all over the place.

Maybe you are right, it can only get better. But I have a bad feeling that this "grain of terror" will resist a reset and will follow me into my grave

[percydaman]

ok your problem was your blinds. move your vray lights inside your blinds. set your environment to black so you dont get skylight and retry rendering. worked for me. will have to post an image later, am out the door.

EDIT: At least I think it was the blinds. It definitely was causing issues anyways. I lowered the early termination amount in the qmc rollout from .85 to .75 and raised min samples from 15 to 20. Am rendering now, will see how it looks.

[noobert]

That sounds great man!
I've also noticed that if the scene gets brighter the grain slightly dissappears a little bit, but not completly dissapears.
If this works I dont have to reset vray like natty said and would save a lot of time.

Thank you very much for your encouragement!

[giraffe]

maybe there is not enough light and
irr map seetings become low due to inadequate light.

please try to tweak lighting.
and please check your model too. once this happened to me because of wrong triangulation.

[noobert]

and please check your model too. once this happened to me because of wrong triangulation.

that could contribute to it, because the case has a "dirty booled mesh" there are a few hundred holes in it.
I' ll put a chamfer cube at the same place, apply the alu material to it and have a look if this makes a difference to the Barebone mesh!

Thanx for your suggestion giraffe!

[percydaman]

ya I tried replacing just about ALL of your meshes though, and still got this horrible black mange until I took your vraylights and put them INSIDE the blinds. then it was fixed. Vray was having issues with the lights, and yes it got alot brighter once I did that.