Sunlight shadows through glazing

V-Ray for 3ds Max V-Ray for 3ds Max :: General
1

Hi

I am working on an architectural interior - office atrium, lots of glass. The best and quickest way for me to get a good GI solution (without using caustics etc) is to hide the glass whilst it is calculated, and then use this solution with the glass visible so that I get all the nice reflections everywhere.

The image rendered without the glass shows all the nice sun shadows streaming in through the glazing. But, when I unhide the glass, use the saved solution and render, the shadows are missing (what I mean is, the glass seems to be stopping the light passing through and creating a partial shadow). What is the best way to use a saved solution yet still have ‘transparent/tinted’ shadows from all the glass work?

Under ‘object settings’ in the system rollout, there is a tick box for Direct Light Shadows - what is this for and how does it relate to right-clicking on geometry, going to properties and de-selecting/selecting the ‘cast shadows’ option?

Examples:
http://www.blinkimage.com/vray/noglass.jpg
http://www.blinkimage.com/vray/withglass.jpg
Thanks

Rich

2

do you have affect shadow turned on?

3

Ah - I knoew there was some button I hadn’t clicked somewhere! I’ve never had this problem b4 and it was driving me crazy!

Thanks da-Elf!

4

I have been selecting glass geometry, and excluding them from GI in the system dialog - is this wrong? - it seems a nicer solution than unhiding and hiding all the time.

5

yes it is wrong.
The thing with the GI setup is that the GI peramiters found in the wrapper and the object properties allows you to stop it fro casting GI and recieving GI. but no peramiter is there to stop it from blocking GI