Alpha channel rendering...

[areafilm]

Hi..is it possible render a model subject with alpha channel? Without background... Thanks

[DayVids]

you have to make a luma matte and use that to remove the BG.

[jakchit]

ooh, could you explain how to do this?

Big thanks
Jack

[DayVids]

essentially just set all materials to emit white, and set background to black.

let it cook till it's in good shape, maybe make it a double resolution just to help get clean edges,

Save that image, and then use in your compositing application as a luma matte.

[DayVids]

also, set any materials you have that you don't want included in the alpha pass to be black, and make them textured emitters black with 0-power.

Change your display method to Direct lighting ( for faster results ) with a bottomed out pathtracing and AO dist.

[jakchit]

thank you for the tips bro.

[ROUBAL]

However, half transparent and blurred object will not give a good mask, I fear... ?

[matej]

No they won't. I hope that proper alpha comes in v6