Background Shader problem.
 

Hi,
I thought I would have a try at compositing a simple model
on a photo, to learn how it's done however i have run into some problems.
I placed a model on a plane that was just a Lambert with a similar colour as the photo's 'BASE' and set up lights to get a decent shadow on the plane.
Then I assigned a 'Background Shader' in-place of the lambert on the 'plane' and rendered and saved the image as a .TGA
(Tried .tiff at first but I could only seem to get black or white on the image, i.e. no much 'gradient' on the shadows so I went to .TGA and that 'seemed' to fix that.
Then I take the image into P/Shop and select the "Channels" layer, use the lasoo to select the "alpha" then with it still selected i go back top "Layers/Background" so I select the RGB and then cut/paste into the image... Where I still get no 'gradient' or soft shadows (any transparency) on the shadows - They just come out black?
I'm pretty sure i'm doing something wrong when in photoshop, but have searched these forums and not found answer so far. Any help will be apreciated.

Regards Scraggy

To select your alpha, are you holding control and clicking it?

Alpha Problem Control Click?
 

Thanks Mike,
No just selecting it, i'm not using control key in Maya or P/Shop.
I saw a Tutorial VTM on it the other week somewhere, and have been trying my best to 'remember' it all as I went back today and looked and there's nothing there now.
So basically Mike i'm making it up as I go along. (As per usual)

I assume you mean in Photoshop?

Thanks John

One of the things you might want to look into when you're compositing is rendering in layers. If you render in layers then you can work with each element of the character/scene independantly like say if you wanted to adjust character color without effecting anything else.

I'm not sure how to fix your problem I would have to see everything you're working with in front of me =/

but try rendering in layers in maya first then bring them into photoshop to composite them....

Ahhhhh I see.
 

Hi,
Thanks for the help, I couldn't find much on the internet at all about it, but after working through the help files and the stuff on Alias site, I realized it was a lot simpler than i thought.
Now I see what Mike means and i just go to my Model's Alpha Channel (In Photoshop) and Contrl/drag it across to the background image to composite them.
I had problems before as I was trying to "select" the alpha channel with the magic wand, and do it that way. DOH!

Thankyou very much. Scraggy.