glass problem. reflection caused by refraction IOR change...

V-Ray V-Ray for 3ds Max Issues
1

Hi,
very beginning of a project, and already going mad…

my glass is ugly and doesn’t behave naturally as it always used to do before.

first time i have this problem. i don’t work at my home. i don’t know what can be the problem. or this is a situation i never met.

i’m used to do my own glass with a simple vray mat reflect with falloff, refract250, affect shadows IOR 1.3
it seems REFRACT is causing problems. i cannot get good refraction. usually when i change IOR, it just slightly change what i see through the glass, now it whanges totally the glass, as if it was reflecting, while there is no reflection activated at all.

here is what i get with refract IOR 1.01


here is what i get with refract IOR 1.3 NO REFLECTIONS AT ALL

Could someone point me to something ?
i need to find my own glass back

2

the refraction is not WORKING !!!
refraction is whithe 255 255 255, affect shadows checked.
the volume in the first plan has the same mat.
i really don’t know where the problem would be located
please anyone would have an idea ?

thank you very much.

3

does your glass have any thickness?

4

yes it has a 1 cm thickness…

5

maybe inverted normals?

looks like some model or setup issue. refraction definitly works in vray.
vray needs for glass objects volumes with correct normals if you use refraction.

IOR 1.3 is not of glas by the way. more 1.55 or 1.6.
make sure to use the IOR for refraction and reflection and specular.

cheers
stefan

6

thanks llab
my volumes are very simple. tyhey are 3ds max box primitives, so the normals cannot be inverted or missing, or screwed/
i took a new mat, ior 1.6 all params default. i just changed refract to white. the mat behaves as there was some reflection at 100%
i never saw that before.

same result for the moment for the moment.
i’m asking myself is this isn’t in the render params…

7

man that’s strange
i took a new scen and merged all previous scene in it. it works.

i won’t go deep into that to guess where the problem was. but it will remain as a great mystery in my memory.

thanks all

8

Did you have a map in the reflection/refraction overide at all?

9

no map at all jacks…
thanks