Vray glass won't let enough light come through + too high reflection on glass

[Fahim]

Hey people,

 

First time I'm posting here so excuse me if I'm doing anything wrong.

 

I've been working on a scene for few days now and seem to have few issues with Vray 2.0 for 3ds max 2011 and glass. The scene is set up simply with Vray sun + Vray sky.

 

Below are renders of the two problems i'm struggling with:

 

The first one shows a render of the scene with simple Vray glass material applied to surfaces with thickness. Note that the material is applied to both the glass sheet on the floor and the glass ceiling; Still the sunlight does not seem to want to travel through the glass of the ceiling/roof; this is my first issue. Secondly; looking at the glass piece on floor it is clear that the glass is transparent and everything behind the glass can be seen through! Although this is not the case with the ceiling/roof even though they are both using the same material; the ceiling/roof seem to have a lot higher reflection and you can't see through it at all as its almost acting like an mirror, a very dark mirror.

 

 

The material settings are simple and straight forward;

*black diffuse

* white reflection and refraction

*Fresnel is on with 1.6,

*Max depth for reflection and refraction set to 10

*Affect all channels

*Affect shadows

*Reflect on back side

 

(And I have experimented with changing values and colours of all of these, switching them on and off, it does not solve the problems)

 

In the second render, I selected the glass on the ceiling/roof and unchecked "Cast shadows" and "Receive shadows" through object properties. This allows the light to come through, although not very realistic as it acts as if there no glass there at all and does not reduce the sunlight strength.

In real life the glass would reflect some of the light from the sun and let some through but this way we get 100% of the light through and is obviously not a good solution. I could get away with this as the scene will be photoshopped later on, but the main issue lies within the glass on the ceiling; just like in the first render it is not transparent, but the glass sheet on the floor is. Also, the reflection is too dark and still acts like a mirror.

 

 

All help will be very much appreciated! If you need me to provide you with more information please go ahead and tell me.

 

Thank you,

Fahim

Edited December 31, 2010 by Fahim

[Fernando Lino]

Did you model it in Sketchup?...I'm asking this because a very common mistake is applying 2 materilals (front and back) at the same face...so the back face is not transparent.

- set vraysky as background to see if you can see the sky thru the glass

- check vrayproperties and max properties to see if you turned on/off something that affect the glass

- check if you turned caustics ON...it should be OFF

 

Fernando

Edited January 1, 2011 by Fernando Lino

[alias_marks]

in your glass material, make sure 'affect shadows' is ticked on.

[Ricardo Eloy]

Is this glass part of a Multi/Sub-Material, by any chance?