View Full Version : Alpha channel?

01 January 2009, 02:00 AM
Hello. I've been searching through the forums trying to find the best way to use an image with an alpha channel. So far, nothing that I have tried works. I've tried using the transparency channel. I have really simple images---just an image with an alpha channel to cut out the shape.

I would love it if anyone could point me in the right direction.



01 January 2009, 02:44 AM
Would help more to know what kind of effect you're after.
Is it transparency or something else that you want driven by the alpha?
If you want cutout cards or something like that, look into the sprite shader.

01 January 2009, 06:50 AM
Hi Jaco. Thanks for your reply. Yes, just making cutouts is what I'm after. Just masking out areas in After Effects, rendering as a still with an alpha, and applying that to a grid in XSI. Is the sprite shader the way to go? This shouldn't really be so hard to do...

thanks. T

01 January 2009, 02:55 AM
Raffaele, here's what I'm trying to do----please see attached image. I would like to have the red shape a cutout. I tried the sprite shader to no avail.

I just want the red shape to render, showing the sphere behind.

The source image has a alpha channel.

thanks for your input.


01 January 2009, 03:40 AM
I think that I figured it out. 1, I had to make the alpha channel in Photoshop, NOT After Effects.

And I had to invert it.

thanks for your advice.

CGTalk Moderation
01 January 2009, 03:40 AM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.