I am having some kind of VRay/Material/Light/HDRI problem? (jpeg attached)

[ericbarlow21]

Does anyone know what causes these white speckles? I cannot get rid of them because I do not know what I am doing incorrectly to cause them to appear.

 

I am using an HDR in this scene (which is instanced into all 3 environment slots - GI, Reflect, Refract overrides), VRay sphere lights, and all VRay materials. The white artifacts seem to appear on areas such as metals and glossy surfaces.

 

I am using Irradiance Map and Light Cache

 

Here is a jpeg showing my problem... it was too big to attach here.

 

http://img.photobucket.com/albums/v397/ericbarlow21/help.jpg

 

There are no "overbright" errors...

[cmeraz3d]

Does anyone know what causes these white speckles? I cannot get rid of them because I do not know what I am doing incorrectly to cause them to appear.

 

I am using an HDR in this scene (which is instanced into all 3 environment slots - GI, Reflect, Refract overrides), VRay sphere lights, and all VRay materials. The white artifacts seem to appear on areas such as metals and glossy surfaces.

 

I am using Irradiance Map and Light Cache

 

Here is a jpeg showing my problem... it was too big to attach here.

 

http://img.photobucket.com/albums/v397/ericbarlow21/help.jpg

 

There are no "overbright" errors...

 

I had the same problem when working with some interior images of my own, using photometric lights and light cache too, the same speckles on very glossy shaders such as chrome, but I still having troubles getting rid of that! May be have to try rendering without the light cache or something, if there a solution for this error, promise to share the tip!

[NeonMojo]

make sure "clamp output" is unchecked in your color mapping options

[BrianKitts]

looks like you are having some issues with your AA filter sharpening too ...Are you currently using catmull rom? its ringing on your specular highlights.

[ericbarlow21]

Hello thanks for the input!

 

I will try with the clamp output option. Can anyone explain more what clamp out put is all about? the 3 settings located there (affect background, clamp output, and sub-pixel) I do not understand fully. I have read a few things online but I still do not have a complete understanding of what these do and when I should use them.

 

Brian - thanks as always. Yes, I am using Catmull-Rom. Is this not good? why? Which filter is best to use in this situation?

 

Thanks!

[Guest nazcaLine]

it looks as a light cache problem for me. maybe it's too low, increase it to 500-1000.

 

Eduardo

[ericbarlow21]

Update:

 

i DID actually have clamp out put checked before...

 

I will try to up the LC but I was at 2000 before

 

I am rendering this for a client who wants it at 6000x3400. Does this resolution affect the light cache at all or does it have nothing to do with resolution?

 

I am sending a render to the farm now so I will let you know what works..

 

ALSO - i saw in a thread here that someone once suggested checking the use interpolation box in the reflect and refract material sections. Anyone have any experience using these settings in the material editor?

[Guest nazcaLine]

if it's in 2000, then i don,t think it's a LC problem. in my experience, it's enough with 1300-1500.

 

and about the option of lc for glossy rays, it works FINE.

 

Eduardo

[ericbarlow21]

Hi Eduardo

 

I do have that LC setting checked but the one I was refering to is actually inside the material editor.

 

There is a check box under the reflections as well as refractions section called "use interpolation"... someone mentioned that using these options cleared up all of the artifacts and white speckles showing in their materials.

 

I think though that I must be doing something else wrong within my render settings, lights, or materials...

[ericbarlow21]

Well I ended upi getting rid of those artifacts but I think it was because I changed so many of the original scene elements so I dont feel like i really solved the problem for future purposes...

 

I switched out the VRay lights for IES lights and then changed from Catmull-Rom to Mitchell-Net and that seemed to clear everything up for the time being

 

If anyone has any input as to what causes these artifacts please let me know because I get them often

 

Thx!

[Ricardo Eloy]

Quick guess, here:

- low subdivs on your reflective materials (which appear to have glossiness lower than 1)

- low subdivs on the lights

- high rQMC Noise Threshold value

 

I'm just guessing, here. Take a look at those.

[anvaraziz]

turning off the affect specular under vray lights and make it invisible 'll fix this,,, it happens to me always... hrrrrrrrrrrrrrrrrrrrrrrrrrrrrr..........

 

if u found any other tricks pls let me know too...

[rivoli]

those are aa related artifacts when using sharpening filters with negative values in their curves (such as catmull, mitchell..). quickest way to fix it is to clamp the output and turn on subpixel mapping, or just switching to a non sharpening filter, or turning filtering off altogether.

[jophus14]

I have had this problem before, but it seemed to go away when I switched my IES lighting around. I thought that was the problem. I also had this happen when using certain HDR images. I realize now that maybe it's my Vray settings.

[jreben]

As others have mentioned, it should be fixed by some or all of the following...check on clamp output AND sub-pixel mapping, use area AA, or none, make vray sun invisible. I've had this happen and it was never related to lightcache settings...