glass going black

[restoeboemi]

i got problem with glass, here's the image with mat setting and fallof in reflection slot. glass is box at 0.5 thick

[Dusan_Pavlicek]

I can't see anything

[Fermi]

Does Exit Color affect the color of the problem?

If it does, then perhaps you need to crank up depth or copy your background into Exit color slot.

Fermí, still using 1.09.02u... i'll give 03i a try somewhen :P

[flipside]

Yep, what you see is the environment refracted in that glass. You probabely have a blue color in your max environment, and you also checked the vray reflection/refraction override with the standard black color in it.

mmm but now that I watch it again, I see the other windows don't have this problem, or isn't there any glass in the closed windows?

Just play with your mat settings, loose the fallof map and try vray's own fresnell option, try without fresnell etc...

[restoeboemi]

@flipside : there r no other glass, yes i use vray skylight, which at the 1st frame is black but after 10th its blue as the background (animatable). the image i rendered it is at the 74th frame. i also have tried with mat settings too, but no luck.

[flipside]

did you check the vray reflection/refraction override too? (the one below the skylight)

[restoeboemi]

no, i didnt checked it.
flipside, can i send u the scene?

[flipside]

The problem is your color mapping. You have affect background turned off, so every pixels in your image that shows the background directly (without any transparant objects in between), will not be affected by the color mapping.
But in one window you have glass, through which you can see the background color. Because there is glass in between camera-background, these pixels WILL be affected by the color mapping. And since you seem to use extremely low values for this, the color turnes black.

The reason why your other objects are not black is because you have a very high multiplier for skylight. This compensates each other. The only object it doesn't work on is the glass where you see the background color through. This bgcolor is not lit by the skylight, so it gets very dark with these low color mapping multipliers.

Enable affect background and hit render, you wil see all bg pixels will be black now... Set skylight multiplier to 1 and color mapping values also both 1 and render: problem is gone!

[flipside]

Also, for glass, use black diffuse, near white reflection color with fresnell, and white refraction color. Then use a kind of green for fog color and set it's value to 0.01 to 0.5 (depends on scene and glass thickness, just try highest value first and see if glass is transparant enough)

[restoeboemi]

thx alot flipside! i will try it.
but since i use daylight, if i set the color multiplier to 1, the scene will be very bright. im using gonçalo tricks for max daylight which the color multiplier set at very low value. any suggestion?

[restoeboemi]

its solved! i use override reflect/refract set at 40, and uncheck the affect background. the black glass gone. thx alot for ur help flipside!