CS4 3d .obj alpha/transparency glitch? Help please

[Selos Dae]

Recently I had to reinstall photoshop cs 4 due to a hardrive failure, and I did not have this problem prior to this on the new one. 
Basically what's happening is when I load up my SL model for skin/texturing use and attempt to use the 3d rotate/or draw on it manually, the model becomes partially transparent in various odd spots where I'm seeing through to the back of the model's textures.
I've gone into render settings and I cannot seem to find anything except checking the 'Remove Backfaces' setting which lessened the issue to a workable state but didn't remove it completely.

Anyone else have this issue and find a fix for it? Thanks :)

[Chosen Few]

Can you post some screenshots?

What you're describing could be a normals problem, a camera placement problem, or possibily an alpha sorting problem.  It's hard to guess without seeing it.

Also, what video card do you have, and how recent are its drivers?

Do you have hardware acceleration enabled in Photoshop?

What was the hardware problem, by the way? 

[Selos Dae]

 

Left is normal, right is when I click on it to rotate or draw on. Sorry I didn't think to post a picture at the time and wasn't sure anyone would respond, thanks though.
Graphics card is up to date ; Radeon HD 6950

I think I have hardware acceleration enabled, is there any way to check and be sure, I'm not sure where the option is for it, though I believe it had a pop up when reinstalling that asked me to enable it, I could be wrong.

Do you mean my hardrive problem? I'm not sure what happened, it just slowly died until it wouldn't start up any longer, it was possibly just old or worn out from use, not sure, it was the first one I've had fail on me. (sorry if you were asking for something else hardware related, I'm no master of computer problems in the slightest hehe)

 edit: checked and hardware acceleration is enabled

 

[Chosen Few]

Sorry it took me a few days to reply.  I'm in the midst of working on a feature film, and today is the first day all week that there are a few hours in which they don't need me on set.

Here's my guess at what's happening.  Assuming you have an alpha texture applied to the model, it does indeed look to be an alpha sorting issue.  If I'm my understanding of the model is correct, it's basically cylindrical?  As you rotate and/or move the camera, some of the backfaces from the far side of the cylinder end up more directly facing the camera than the front faces from the near side.  Thus, the backfaces end up getting displayed instead of the front faces. 

If that is indeed what's going on, then there are two solutions.  One is just don't use an alpha texture on that object.  It doesn't appear that you actually need one, after all.  The other is to enable backface culling in the render settings for the 3D layer in Photoshop.  The option is called "Remove backfaces".  You'll find it right in the first section, when you open up the Render Settings dialog (3D -> Render Settings...).

If you don't actually have an alpha texture on that object, then my next guess would be it's either a graphics driver glitch, or a Photoshop glitch.  If it's the former, you'll want to uninstall your graphics driver, restart, and reinstall. If it's the latter, uninstall Photoshop, restart, and reinstall.

It can't be a normals issue with the model, or you'd be seeing it all the time.  So, if none of the above solves it, I'm stumped.

[Selos Dae]

No problem, I actually did turn on the option to remove backfaces during that screenshot, which made it workable, it was actually significantly worse before I turned that on to a point I couldn't even vaguely see what I was doing if I so much as touched it with my pen. That particular texture is not an alpha texture, it seems to happen regardless, I was considering reinstalling PS for sure and see if that helps it because prior to reinstalling it, I was using this same graphics card so I'm unsure of which would be causing it. Thanks in the meantime, I'll post an update if I ever manage to get it fixed.

[Chosen Few]

When you say it's not an alpha texture, are you absolutely certain that that's the case?  If you're working against a transparent background layer, then the working document is a 32-bit image.  Remember, the PSB format, which Photoshop uses internally for texturing purposes (among other purposes) does support simple WYSIWYG transparency, in additon to alpha channels.  Both will respond the same way in a 3D environment.  As far as the computer is concerned, they're the same thing.  Only the user-side methodology differs.

In order for the texture to be truly opaque, it has to be a 24-bit image, meaning no pixel can have an opacity value of less than 100%, and no more than three channels must be present.

If you're 100% positive that there's no transparency data in the texture image, then either something is wrong with Photoshop, or something is wrong with your graphics driver, or something is wrong with your graphics card itself.  The former two can be solved with full uninstalls*, followed by new clean installations.  The latter would likely require replacement of the card.

 

*Keep in mind, your OS cannot fully uninstall your graphics driver on its own.  You'll need to use a dedicated program, such as DriverCleaner, to do it properly.  Also, just in case you didn't realize, Windows Update cannot properly install graphics drivers (despite the fact that it never seems to stop wanting to try). 

As you may know, the only proper method for updating drivers is this:

1.  Download the new driver installer directly from the device manufacturer, but don't run it yet.

2.  Reboot into Safe Mode, run DriverCleaner, and follow the on-screen instructions to fully remove your old driver.

3.  Reboot into normal mode, and run the driver installer you donwloaded in step 1.

If you skip any of those steps, you're bound to run into trouble, sooner or later.

 

Good luck solving the problem, whatever it ultimately turns out to be.  Do keep us posted.