Help rendering a Vray Reflection with transparency

[davidarcila]

Hello!

 

My problem is that I'm trying to render an object and it's reflection with a transparent background as a .png or any image format with transparency or alpha channel. But when doing the render the only thing that has an alpha channel is the object itself (See Image #2), not the reflection which I'm also trying to get.

 

Im using 3ds Max 9 along with Vray 1.5

 

I don't know it it has to do with a material property, render elements...?

 

Any help is appreciated.

 

 

 

This is just a recreation i made in photoshop of what I'm trying to get, the object and it's reflection with transparent background

 

[Cocytus09]

Hello David,

 

I would approach it like this:

 

In 3ds Max create a plane under your object.

Create a new VrayMtlWrapper material.

In the Base Material create your material with desired reflection parameters.

Make sure the VrayMtlWrapper material has the Alpha Contribution set to -1.

Apply the material to your plane.

Change your environment background color to pure white.

Render out to a .png file.

 

 

 

 

Hope it helps David!

[davidarcila]

Hi Edson!

 

Man, you just gave me the answer i needed. I did what you told me, and it worked perfectly, i got the reflection in the alpha channel...problem solved.

 

Thank you very much

[Cocytus09]

You're welcome David.

[son of the sun]

hi guys.

 

im a maya user.and im using vray.

now my question is.there's a shader in maya called use background and it doesnt work in vray.now can it be done with any vray materials.

 

 

reflective plane but transparent.

 

thanks.

[varribas]

Cocytus09 i'm really interested to export the fully reflection with alpha and is almost imposible. If I'm not wrong, the reflection with alpha you get is thanks to the shadow the cube do.

 

so you exports the shadow as an alpha and the reflection is also because is over the shadow. not?

 

Is no other way to export reflections? There is no way to exclude the background for the goundplane reflection?

 

Thanks!

[cyberoid]

Hey there,

 

I think that the only reason the reflection appears in the alpha channel, is because it is included in the shadow. If the reflection is partly inside the shadow, then only that part of the reflection will be in the alpha channel.

 

In the Matte properties, there are two check boxes "Shadows" and "Affect Alpha". It seems like there should be another check box saying "Reflections"!!!

 

If anyone else knows a workaround plz share, because I am stuck on this one! :confused: