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digitalimagery
12-02-2011, 10:15 AM
I don't know what I did but I can't seem to get a still frame (a simple flat screen monitor) to render with an alpha. I keep getting a solid white image in the alpha channel.

The only thing I can think of is I'd been using a background image to create a reflection but turned it off and still get a full white alpha channel.

Any ideas where to look?

I know this is real basic but I've always gotten them before so I never knew how to turn them on or off. I've even tried outputting a single frame with render scene with alpha and just outputting an alpha and the result is the same.

Thanks
DI

Sekhar
12-02-2011, 11:07 AM
Why don't you post your scene?

digitalimagery
12-02-2011, 11:10 AM
Com'n at ya.

Thanks!
DI

nickdigital
12-02-2011, 11:11 AM
Need the object(s) and image(s) too.

digitalimagery
12-02-2011, 11:32 AM
Images shouldn't be necessary to trouble shoot the alpha output. Must be a squirrely setting I'm unaware of (or never use). Here's the model anyway.

Thanks.
DI

digitalimagery
12-02-2011, 11:48 AM
Could closing the file, opening a different file and then re opening the file have anything to do with this issue? Because this is the only thing I did other than turn of two sided poly's in the surface editor and now I'm getting the proper alpha.

Things like this drive me crazy when I'm under the gun. I mean I turned nothing off/on and just started not getting alphas. Still did nothing and now I'm getting them.

There was a piece I geometry I had tried using to reflect something in the screen but I had deleted it from the scene completely thinking this was what was causing the problem (after turning on ignor by camera and still had the problem).

Does LW require you close the file and reopen to acknowledge geometry was deleted?

Thanks
DI

Sekhar
12-02-2011, 12:02 PM
Images shouldn't be necessary to trouble shoot the alpha output. Must be a squirrely setting I'm unaware of (or never use). Here's the model anyway.

Thanks.
DI

I'm seeing the alpha correctly (just the tv and the support). Tried on 10.1 and the new 11.

BTW, 10.1 rendered it in 2m 39s vs. 11 that did it in 7.9s. That's incredible! 11 changed the settings, but I added AA back on and the 7.9s is with AA. See the two results below, they aren't too far apart.

gerry_g
12-02-2011, 12:03 PM
Per object in 'Object properties' under the 'Render' tab there is an alpha setting drop down, if you have an object blocking the background you should change it to unaffected by alpha so as to avoid the the problem of ending up with a completely white alpha, this don't work experiment !!

digitalimagery
12-02-2011, 12:08 PM
Sekhar and Gerry_G

You probably saw my note about the alpha "magically" reappearing. I guess the rule of thumb is if something acts weird, save, restart and try again.

Either way good to know about the alpha setting (which I never changed btw) and I had previously turned off, then eliminated the background image.

Mucho appreciato (Spanglish):)

DI