compositing in photoshop with alpha channel

[Munz]

I have been trying to composite a 3d rendering I did in max 7 with a photograph background in photoshop using an alpha channel. I can see the alpha channel in photoshop, but do not understand how to make it into a mask to effect the transparency of my image (I am assuming this is what I need to do). Does anyone know how to do this or know of a tutorial I could refer to.

 

thanks

munz

[Juan Altieri]

just select the alpha channel in channels floating window, and press the button "load channel as selection" (in the bottom part of this floating) this will select the white areas, go to the rgb channel (the first one) and you have the selection ready to cut or copy into the background image..........

[Ernest Burden III]

You can also go to selections>load selection and get a pull-down list of all transparencies in the file--any alpha channels (there can be many) plus any layer with transparency--you choose to load it, invert it, add it to a current selection or subtract from...(from memory on my part, I think I covered it all).

[STRAT]

http://homepage.ntlworld.com/sjleworthy/wp-02/red-p02.html

http://homepage.ntlworld.com/sjleworthy/wp-02/vil-p02.html

[doraima]

What you could do is create a diffuse map and an opacity map on what you are applying to.

 

 

http://www.worldoftrainz.com/Pages/TutorialsTRS/3dsEffectsTutTRS.htm

 

Here is a similar tutorial being applied with diffuse and opacity maps