refraction problem

[teabag]

hello
we r having difficulties with one of our scenes.

we have a magnifying glass like object on black background with loads of things to reflect, but we cannot seem to have it redered with alpha

the material itself has affect alpha checked
background is black
vray GI environment with vray sky
the rest of environment tabs r unchecked...

think we r missing something ....can u help please?

cheers martin

[DaForce]

Hey Martin

So what alpha are you getting?

Are you able to show an image of the render and its associated alpha?

[MoonDoggie]

^ So needy, were you at Siggraph DaForce?

[DaForce]

Nah mate, couldnt make it

[ruud3dv]

Check the vrayproperties for the object, there's an alpha contribution setting there which at default should be 1,0

Btw: in the helpfiles it's mentioned that affect alpha for refracted materials only works for non-glossy refractions

There's also a checkbox for affect alpha for Direct light, dunno what that does but it might be worth fiddling with.

[teabag]

got it sorted guys...the problem was that we animated a charcter with a spyglass in front of it and the spyglass refraction was so strong that it was refraction more the surrounding environment than the black background.....had to do a few tweaks with refraction IOR and it worked ....

thanks for replies ...will post the link to the whole project soon

best regards

Martin