32 Bit Render?

[CADTutor]

I'm trying to render a model in 32 Bit so that I get a selection alpha channel when I pull the image into Photoshop. This all worked fine A2006 and below. But in A2008, each time I set the file format to 32 Bit, the radio button works clicks on but I only get a 24 Bit render. When I go back, the default has been set to 24 Bit. This happens with both TIFF and PNG.

Any ideas?

[CADTutor]

Hmm, I guess no one else has this problem. It's very annoying because I rely on this very handy feature of the AutoCAD renderer. I guess it must be a bug. Does anyone know if this works in 2009?

[dzatto]

I don't render through ACAD, but if you post a quick "how to", I'll try it and see. I'm using ACA2009 though, not vanilla cad.

[CADTutor]

OK, so you'll need some 3D object to render - can be very simple like a box or cylinder.

Go to the Advanced Render Settings panel and click the small floppy disk icon at the top where it says "Render Context". Then click the option "Output file name". Set the file type to TIFF and enter file name/location. When you click Save, tou see a small TIFF Image Options dialog. Select the "32 Bits (24 Bits + Alpha)" option. Then OK. Next, click the Render icon (teapot and flash) at the top of the Advanced Render Settings panel. The Render window will open and your image si rendered and written to file.

Open the new TIFF file in Photoshop and click the Channels tab - no Alpha channel!

Older versions of AutoCAD (2006 and earlier) rendered an alpha channel as well. This meant that the rendered object could be selected in Photoshop - it even worked for opacity as well. But not any more.

[dzatto]

Well, I got it to render, but unfortunately I just got a new machine with Vista 64. My photoshop loaded, but it's telling me that my license number is invalid and it won't launch. IT says it's a Vista thing and he hasn't figured out a work around yet. Anyway, here's the TIFF file, see if it has the channels on your machine.

Okay, nevermind. You can't upload a TIF here. Invalid file type. If you want. PM me your email and I'll send it to you so you can see if it works.

[CADTutor]

OK, thanks for that. I got your TIFF and guess what? No alpha channel. :(

Looks like I've just got to spend more time making manual selections in Photoshop - either that or go back to AutoCAD 2006.

I guess this issue is just too niche for Autodesk to care too much about it but surely if the feature doesn't work there really shouldn't be an option for it.

[dzatto]

OK, thanks for that. I got your TIFF and guess what? No alpha channel. :(

Looks like I've just got to spend more time making manual selections in Photoshop - either that or go back to AutoCAD 2006.

I guess this issue is just too niche for Autodesk to care too much about it but surely if the feature doesn't work there really shouldn't be an option for it.
Damn, that sucks! Are you on subscription? If not, I can put in a support request and see what they say. There may be a work around.

[spacedecor]

I'm trying to render a model in 32 Bit so that I get a selection alpha channel when I pull the image into Photoshop. This all worked fine A2006 and below. But in A2008, each time I set the file format to 32 Bit, the radio button works clicks on but I only get a 24 Bit render. When I go back, the default has been set to 24 Bit. This happens with both TIFF and PNG.

Any ideas?
That is your solution?Don't use render to file.You should do from render window. Pls reply me OK or NOT.