Fine opacity map detail and Alpha channels

[Smalerbi]

Hello,

I have a question about rendering very fine opacity map detail and Alpha channels. Please see attached. This is a partial image that was saved as a Tga file. I then knocked out the background in PS. I placed a black background behind the rendered image so you can see the problem. Could someone please tell me what the trick is to preventing this....if there is one.

thank you,

Scott

[Dariusz Makowski (Dadal)]

You need to save as unpremultiplied EXR and then premultiply it with alpha in post.

[MoonDoggie]

I render on black so it's already pre-multiplied.

[Smalerbi]

You need to save as unpremultiplied EXR and then premultiply it with alpha in post.

Interesting. I did not know EXR files maintain a better Alpha integrity. Thanks for the tip. My PS skills are a bit basic. Without getting into a long winded explanation, could you please tell me what the best method to clean up balance of the image?

Thanks..

Scott

[Neilg]

Render onto black all the time.

[Smalerbi]

Render onto black all the time.

Thank you. This may be a stupid question but if you are using Vray Sky.......how do you get the background to be black? Please do not tell me I need to create a Vray dome light and place the Vray Sky map in the lights map slot. That increases the rendering time 2 fold.

Scott

[Neilg]

in the vray render settings proper, use the environment override. add the sky to the gi and the reflection override then make the main environment color black.