Vray - strange DOTS on glossy surfaces.

[Lucas Sztukowski]

Hi there!

I`am kinda new on this forum, and unofrtuletly my first post is a problem that i have with my vray render.

 

 

here you can see a part of my scene, the problem is that on every glossy surface as the chairs, table ect. iv got some strange white DOTS. Please help me guys! I`am using Irr. map + light cache. In the scene i`v got some VrayMtl lights + target spotlights(with vray shadow).

Please HELP!

Edited August 14, 2008 by Lucas Sztukowski

[olbo]

Hello Lucas,

 

sorry I can't see your pic, ... file not found. Do you have warnings/errors

in the Vray log? If so, what kinda errors you get. Especially if you get

errors like "invalid lightmap" and/or "overbright material" ... or something

like this, then your render can/will look pretty bad.

 

If your logfile doesn't show any error ... then I dunno. So if you've got

"invalid lightmap" you should check your sample size, maybe it is to small.

If you've got "overbright material" then you've exceeded the allowed

RGB value. So do not ever use "RGB 255" for color, reflectivity and

refractivity, use 254 instead. And check if you "clamp" your colors

under the "Color mapping" options. This can help also.

 

Hope this will help you a lil bit. Keep in mind I'm pretty new to Vray too. ;o)

 

 

 

take care

Oleg

[Lucas Sztukowski]

Hey Oleg!

Thanks for reply. I just menaged to get the right results! (yeey!).

The problem was i did not switched Interpolation in materials glossines. So thatswhy i had some funny dots all over glossy surfaces. I`ll probably will show in the finished area what i`am trying to render.

Sorry you can`t see the picture, after i`v fixed it i just deleted the picture form my account.

... anyway... Vielen Dank *thumbs up*

[ShaunDon]

Lucas --

 

That may be one way to get around the problem, but only because you're dumbing down the way V-Ray calculates the glossies. You're not really solving the underlying issue, and your glossies will not look as good when interpolated (though they will render more quickly).

 

For 99% of "strange *insert color* dots" issues in V-Ray, it is because of an overbright error as Oleg said. Keep the V-Ray Log open and watch it. At some point in the rendering (usually shortly after it starts, but it depends on how you're calculating indirect light) you'll start to get a trickle of overbright errors, and depending on the scene it may turn into a deluge. Cancel it as soon as this starts happening.

 

Overbrights usually occur in a cascade sequence -- maybe only one or two objects are actually generating it, but they begin to affect everything else in the scene, especially if they're reflecting the offending object. Start with the material of the first object that gives an error and darken it so it bounces less light. You should see at the very least an immediate reduction in the number of errors. Continue doing this until they don't occur at all.

 

FYI for the future. Overbrights are very common errors, but the log is always your key to tracking down the culprit. Good luck!

 

Shaun

[Lucas Sztukowski]

Hey ShaunDon,

I preaty shure your right, but this was not the case. I simple did not turned on the interpolation in glossy materials, so only glossy surfaces had some white dots on the surface. After clicking the interp. ON the problem disappeared....

 

Thanks Shaun