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View Full Version : png32 alpha for use as texture, no transparency



pearlwaterdrops
01-19-2007, 10:40 AM
hello;

I have a 32 bit png file ( from fireworks );

in LW7.5 modeler I select a surface ( surface editor ) and click the T from the color channel ( surface editor );

I load the png image;

the transparency does not show up;

any thoughts?


dsdsdsdsd

lion111
01-19-2007, 11:56 AM
no idea but maya does

Lightwolf
01-19-2007, 12:29 PM
Does it show up in the image editor?

Also, the alpha channel in LW defines the transparency of the texture layer, not of the surface.

Cheers,
Mike

pearlwaterdrops
01-19-2007, 12:43 PM
Mike, surface editor -> color channel -> T -> image=my32.png -> does not show up in the image editor, instead white where alpha is supposed to be; also does not show up in viewport with texture-view;

Pagnozzi, in the screenshot, does blue = alpha, and if so how do you know?

dsdsdsdsdsd

Lightwolf
01-19-2007, 12:54 PM
Mike, surface editor -> color channel -> T -> image=my32.png -> does not show up in the image editor, instead white where alpha is supposed to be;
Well, if the alpha channel doesn't show up in the image editor, then LW hasn't loaded it, or there may be none in the image...

Cheers,
Mike

Dave Jerrard
01-20-2007, 03:12 PM
I've been using 32 bit PNG files quite a lot lately, and I haven't had any problems with the alphas in them. Older versions of LightWave did have some glitches with PNG files - the main one being they would flicker in brightness during an animation, but that's long since been resolved.

Maybe the problem rests in what you used to create the image in the first place? I have seen differences in alpha handling depending on how the image is saved. You might want to take a look at that process.


He Who Has A Few Good Test Images For Alpha Handling.

gerry_g
01-20-2007, 04:24 PM
On the Mac at least 32bit png's have no Alpha, that is to say yes they do have transparency but it is integral to to the RGB, and does not show up as a standalone Alpha Channel, I first thought this was a quirk of CS2 where when saving out an object with transparency to the png format the Alpha option is grayed out (even if you physically add an Alpha Channel first) conversely if you save out a 32bit png from Lightwave again you get no Alpha (but the transparency is there), png’s on a Mac have been odd ever since OS vs.8.4............so I have to ask the obvios, has this file been anywhere near a Mac!!

toby
01-29-2007, 12:05 PM
On the Mac at least 32bit png's have no Alpha, that is to say yes they do have transparency but it is integral to to the RGB, and does not show up as a standalone Alpha Channel, I first thought this was a quirk of CS2 where when saving out an object with transparency to the png format the Alpha option is grayed out (even if you physically add an Alpha Channel first) conversely if you save out a 32bit png from Lightwave again you get no Alpha (but the transparency is there), png’s on a Mac have been odd ever since OS vs.8.4............so I have to ask the obvios, has this file been anywhere near a Mac!!
That's not quite right, you can save a PNG with an alpha channel on the Mac, I do it all the time, even with 8bit images. The transparency you get in PS is just the way PS is interpreting the alpha.

Note that with Pagnozzi's second image, he's applied the image to the Transparency channel, not the color channel. Is that the kind of transparency you want?

gerry_g
01-29-2007, 12:41 PM
Like I said it has no alpha no extra separate 8bit channel the way you would expect with some other formats like taga or tif or psd., clearly it still has alpha properties or it would not be able to show transparency, but its transparency is not a function you can save or enable the way you can on a PC, on a Mac transparency or alpha values are implicit and if present are automatically saved in 32bt format and if not ignored, but Photoshop offers no overrides or choice.

toby
01-29-2007, 09:51 PM
True, you have to select your alpha channel and crop your rgb with it.