another glass question

[ntavian]

Hello all , this is my first post here

my question is regarding modeling glass in autocad (to be later file linked into MAX) does Vray prefer: Solids, 3d faces, or just lines with the extrude modifier applied?

It seems like Vray transparency works better with objects that have a thickness (2 sides) rather than simple sheets of glass.

please help

[joconnell]

It needs two sides - when light bends through glass it goes in and then out of the glass - vray does the same thing so if you only had one side to it, it makes vray think that the rays have gone into glass and never come out so it'll make everything behind the glass look magnified as if encased in the glass - easily fixed with the shell modifier in max though.

[percydaman]

you only need 2 sides if your going to use proper refraction. If your going with simple opacity and reflection, 1 sided is fine. Which is what I use alot tbh.

[ntavian]

hey thanks for the help,

when I go with 1 sided glass, it seems some planes render completly black, and if some of the "normals" are facing in, they dont even show up with transparent materials applied to them, but show up with materials with no transparency apllied

question 2: when using 2 sided glass does it increase render time?

[MoonDoggie]

If it's a vray material and you're using the refract slot you need 2 faces.
(Vray materials are 2 sided by default)

If it's a standard material and you're using the opacity slot, you need 1 (line with extrude is fine)

Question 2: Yes, simple tests with 10 windows will prove it