making an alpha with max grab viewport (for selection purposes)

[boyluya]

Ok so I'm getting hooked with these realtime shaders in max, but I want to change the plain background in photoshop. My question is how do you guys make an alpha for selection purposes with max's grab viewport. Thanks.

I think in maya when you use hardware render it will automatically make an alpha for you and that's what I'm looking for within max. :poly121:

[BradMyers82]

Hey Boyluya, Personally what I do for that is create another material that will make your character pure white and apply it.

The easiest way to do this is to use a white fresenel color and turn the strength way up and the power way down.

So get your camera setup how you like it. Take a screen grab with your final shader, then apply the white fresnel shader for the alpha. Grab that, and your all set. :)

[boyluya]

That was quick brad, thanks. What kind of material? Max's standard material or the same realtime shader I'm using?

[BradMyers82]

I use the same real-time material. Haven't tried a standard max one, but I'm sure there is a way for that too. I have done exactly what you are trying to do with both 3 point shader and Xoluil. Your probably using one of these, so which ever one you are using, go with that. ;)

[boyluya]

Ok, thanks again. ^^

[Microneezia]

i feel so redundant. awesome idea Brad!

[swytch]

I may be misunderstanding what you are looking for, but for a standard material to make an object all white I use Self Illumination set to 100%.

[r_fletch_r]

i've got some great results by rendering on a full green/blue ground plane and key it out in photoshop.

Where this is better than the white on black alpha is you preserve cast shadows and viewport AO

This was done on green and keyed (all be it very quickly, you could defringe it for a better result)
http://www.robertfletcher.org/pictures/albums/userpics/teapot_alpha.png

there is a tutorial on keying in PS here (http://photoshoptutorials.ws/photoshop-tutorials/photo-effects/keying-green-backdrops.html)