Vray Glass

[JamesTaylor]

The 2 attached images show the truck rendered with identical materials.

 

In the 1st the windows are made from a single sided mesh... as you can see the reflections work fine but i don't get the correct transparency to see the wall through the windows.

 

In the 2nd Image, i have given the window meshes a thickness and rendered with exactly the same materials applied.. now everything works correctly, reflections and transparency.

 

So my question is... is there a setting in the vray material that will "correct" the issue of transparency caused by only having a single sided mesh for the windows???

[Trevor Tizard]

Have you tried the two sided material...........just a thought?

 

Alternatively, is there a problem with just applying a shell modifier to the glass?

[JamesTaylor]

I haven't tried using the 2 sided material... actually i've never tried using it at all, i'll go and read about it now!

 

There isn't really a problem with applying a shell modifier to the glass... i'm just being slightly lazy (i'm converting a couple of car libraries across to Vray Mats and have 50 or so to do) and thought there may simply be a check box which would tell vray to treat it as if its shelled...?

 

Struck me that the problem had the potential to have a very simple solution... rarther like just checking affect shadows instead of excluding glass from casting shadows in its properties

[Crazy Homeless Guy]

i believe this has to do with the index of refraction (IOR) of glass. when light enters the first side it is bent, when it enters the second side, it is bent back, or close to back. your window only has one side, so it is never bent back.

 

http://www.carsoncity.k12.mi.us/~chuck_peirce/Parfrt09.gif

 

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[JamesTaylor]

I kinda guess the cause would be along the line you have indicated travis, i was hoping their might be a "quick switch" type of method to solve it tho...

 

i've got quite a few of these to do and much of the glass is set with MatIDs in the models... its meaning a few extra steps to detach, shell sort out each time... a nice little tick box solution would be appreciated here, got a feeling i'll be doing them all the long way tho!!!

[JamesTaylor]

I should also mention i tried the 2SidedMat Trevor suggested, which only seemed to invert the problem, instead of the windows rendering as black they came white!!

[M_Jaco]

See if this helps.

 

http://www.chaosgroup.com/forum/phpBB2/viewtopic.php?t=17187

[NeonMojo]

travis is right on this one... the IOR should be something around 1.517 for typical glass i believe, but something close should work if you are using a two sided mesh. If you are using a one sided mesh, then turn down the IOR to something close to 1 like 1.01. This should give you a similar look to the two sided glass but you lose "100% accurate" refraction if that matters to you...

[dengen]

@JamesTaylor

 

I found out, that under the "Options" of a standard "V-RayMlt", you can opt to reflect the surface "...on back side" either, and that might have an influence on the refraction also.