Rims with alpha

[Numse]

I´m rendering a car part by part and compositiong them in photoshop. But when I´m applying the alphas they don´t fit correctly.. I have read some about it on the forum and as I have seen there is only one solution, using layer -> matte options i PS. But it doesn´t work very well either..

I thought something as important as this would have been fixed ages ago..

[vlado]

Can you post an image of your problem or email it to vlado@chaosgroup.com?

In addition to the matte option in photoshop, make sure that you have rendered your objects against a black background.

I am not quite sure if AA filters can influence this, but it is probably better not to use sharpening antialiasing filters (e.g. catmull-rom or Mitchell-Netravali).

Best regards,
Vlado

[Numse]

I´ll see if I have some spare time over later so that I can send you a render.

I´m rendering with a white background right now. Why should I render with a black background?

I´m using michell right now.

[instinct]

because rendering on non-black backgrounds introduces problems in AA Areas as AA pixels are basically semitransparent thus taking up the backgroundcolor.

Regards,
Thorsten

[vlado]

You can find some discussions and solutions for the same issue in these threads:

http://www.chaosgroup.com/forum/phpB...g+alpha#146362
http://www.chaosgroup.com/forum/phpB...ng+alpha#35867
http://www.chaosgroup.com/forum/phpB...g+alpha#144455

Best regards,
Vlado

[Numse]

I´ll check out the links.

I´m sending you a PSD-file right now where I´m showing the same problem as before, this time with black background.

[Da_elf]

this is why i usually like to use striaght for my alpha channel in my tgas