Alpha channel all white, unable to separate background from the model

[dilushan]

Hi guys,

 

I'm having some issues with alpha channel, every time it become total white except miner reflections become black( like 0.5% of total image) I've tried to change sky or background alpha amount, but i couldn't find any settings for that either. I want to get a proper alpha channel to edit backgrounds in Photoshop

 

Could you please give some advice?

 

Thanks, Dilu

[cg_Butler]

Maybe you could explain your scene in a bit more detail. Are you using a sky dome? Or just background image, or even a HRDI. Is it an external scene, or an internal one looking through a window?

 

Steps to try.......

 

1. Make sure your glass is affecting Alpha in the material.

2. If you are using a dome light, tell it not to affect the Alpha in the Dome Light rollout when the light is selected.

3. If you have a skydome, select it and right click on it. Choose VRay Properties and set it's alpha contribution to -1.0. This will still be visible in the render, but not in the Alpha channel.

 

I hope one of these fixes your issue. If not, post again!