Transparency Halo Issue

This one's got me a bit confused. I'm trying to do a few textures for a four segment flexi-tail so that it looks like one smooth tail (instead of four cylinders all tapered by various amounts). I've got the right segments painted and there's no seam issues, however along two (and only two textures of four!) edges of the prims there's a white halo along the edge of the prim. I've filled the alpha channel with black except the respective segments which require colour, I didn't use anti-aliasing while selecting, no feathering, nothing. For good measure I even drew black along that edge of each texture with no selection and using the pencil tool. Yes I'm saving as targa, yes I'm saving as 32 bit textures, yes I see correct transparencies in SL (except for the halo on that one edge of the two textures). Using Photoshop CS2. Upon request I can host the offending textures.

Download Flaming Pear's Solidify and apply it right before you save the targa. It's a lovely tool for removing the halo effect.

Nope, not doing it for me. I've tried all three solidify modes (there's A - C apparently) and none of them get rid of that halo. Any other suggestions?

It sounds like there's a terminology mismatch here. If I'm reading you right, then what you're seeing is not what we commonly refer to as "haloing", so it's not all that surprising that you're getting the wrong advice about how to fix it.. When we use the word "halo", we usually mean a translucent ring of white pixels directly surrounding the opaque parts of a partially transparent image. "Haloing", under that definition, is not an SL-specific problem, but simply the result of incomplete technique on the part of the texture artist. The Solidify suggestion would be one way to fix it, if indeed it were what you're talking about, but by your description I'm guessing you're talking about something else.

It sounds much more like what you're seeing is the typical "white line" that sometimes appears along the edges of transparent prims. Unlike the halo, the line is very much an SL issue, not a texture preparation issue. Because SL never clamps textures, but tries to tile everything, each edges of every texture is always anti-aliased with its opposite edge. In other words, the pixels along the right edge are blended with the pixels along the left edge, and the top edge pixels are blended with the bottom edge.

Ordinarily, this is undetectable, but in situations where you've got an opaque edge opposite a transparent edge, it causes problems. Some of the pixels from the opaque edge bleed over onto the transparent edge, causing the appearance of a faint line.

There are two ways to get rid of the line. One is to shrink your texture a bit in Photoshop, without shrinking the canvas, so that you have some transparent padding all the way around. If all edges are transparent, the edge-to-edge anti-aliasing will also be transparent. Then simply set the repeats per face in SL to less than 1, so that the texture stretches to fit the surface the way you want.

The other way is just to lower the repeats without redesigning the texture image. Usually, setting it to 0.99 will be enough to get rid of the line, without really messing up the texture's visual appearance too much.

I hope that helps.

Thanks, that got the ring out. That actually makes quite a bit of sense. Just wish SL didn't do that.

This seems to be a similar problem.

I've made a skirt with transparent areas, there are dark lines around the transparent areas. The dark lines are not caused by semi-transparent anti-aliases pixels, I make a texture without anti-aliasing.

Example in the attached file.

Looks to me like you put your pink skirt over black background, then youselected it, and flooded the selection with white in the alpha channel. The pink of the skirt itself wasn't anti-aliased, but the white in the alpha channel was. As a result, you've got a large portion of the black background showing.

Give the image a pink background instead of black, and it should clear up the problem.


And turn anti-aliasing back on. Those aliased, jagged edges look pretty terrible.

Thanks for the help Chosen. I don't understand how to give the image a background. Would you point me to a tutorial.

I use the Gimp. I made the shape of the skirt with a channel/alpha mask. The Mask has a black background, I drew the shape with paths and made a selection which I filled with white.

Thanks