pane of glass

[pete]

hi there.

how could i get real panes of glass?? i try whit vray mat whith reflect on white, and whit hdri for the reflections, but i can´t get good reflections on flat surfaces. what have i do?

thank you.

[GoncaloP]

Try to use a black color on the diffuse slot; white on reflection with fresnel checked; refraction white; fog tint with a very light color; check reflect on back side and uncheck double sided.

Gonçalo

[pete]

thank Gonzalo i will try :P [/code]

[pete]

the panels i whant are for the out side of a building...i whan the mirror efect..

[percydaman]

for the mirror effect put a falloff map in the reflect slot of the vray mat and then adjust the falloff how you like

[pete]

thank you. i will try. them tell you.

[flipside]

Try to use a black color on the diffuse slot; white on reflection with fresnel checked; refraction white; fog tint with a very light color; check reflect on back side and uncheck double sided.

Gonçalo

Why uncheck double sided?

[GoncaloP]

Because it does nothing to refraction!

Gonçalo

[flipside]

Hu? I thought that with no double sided material the refracted ray will bend forever because it never meets the backside of the object?

[GoncaloP]

I thought that too until Vlado says that it doesnt, and I belive him.

From the manual,

Double-sided - this option specifies whether VRay to assume all geometry faces as double-sided.

Reflect on back side - this checkbox forces VRay to trace reflections always (even on back sides of the faces).

Gonçalo

[flipside]

Hi, if this 'pane' is a plane without thickness I understand your comment. I did some tests on a simple glass model and noticed some interesting stuff:

double sided ON, reflect on back OFF:


double sided ON, reflect on back ON:


double sided OFF, reflect on back OFF:


double sided OFF, reflect on back ON:


Note the differences in rendertime and differences in the actual look...

[GoncaloP]

Hi flipside,

Thanks for the tests they are really helpful, however I can note the differences in rendertime but its difficult to see the results on the images, can you post a biger ones?

Gonçalo

[corey]

Flipside,

Can you post your scene...

[flipside]

Sorry, demo version... I didn't save anything!

But I can tell you (or just download them and view them in acdsee or something to note the difference).

There is absolutely NO difference in look between render [reflect on back=off & double sided=off] and [reflect on back=off & double sided=on]


There is a difference if you set reflect on back on or off, but also small. Here and there some more reflections appear.

But there is also some difference between [reflect on back=on & double sided=on] and [reflect on back=off & double sided=on]


Hope you understand me...

But don't ask me what conclusion to pull out of this all!

[GoncaloP]

Well, here you can see some difference

Reflect on back side on and Double sided off


Reflect on back off and Double sided off


Exacly the same settings on the glass material and light the only difference are the mention options.

Gonçalo