White Edge Of Transparency

[cah8222]

Hi,

I used "transparency" to make an irregular wing from a flat nurbs.
It seems good, at least I like it.
However, the border of the texture appears white edge.
Does anyone know why it happen and how to fix it???

400) {this.resized=true; this.width=400; this.alt='Click here to open new window';}" onmouseover="if(this.resized) this.style.cursor='hand';" onclick="if(this.resized) {window.open('http://www.rit.edu/~cah8222/imm/pix/test2.jpg');}" />
400) {this.resized=true; this.width=400; this.alt='Click here to open new window';}" onmouseover="if(this.resized) this.style.cursor='hand';" onclick="if(this.resized) {window.open('http://www.rit.edu/~cah8222/imm/pix/test.jpg');}" />

best,

Hsiang

[drblacksnake]

thats because texture was painted on white.. take Your favorite image editor and add at least gray color to area which is currently white. otherwise crop alpha for a pixel or two.

[joojaa]

or make inverse mask of white that you subtract form the texture. this is what you get with premulted alpha.

[cah8222]

Thanks a lot for the reply.

However, I don't think it's the problem.
Because I used psd network for this texture.
In the color layer of that psd file, I didn't paint any white color in it.
Actually, the white part you see from the node is totally empty.
Guess the default of maya make empty/transparent part look white.

And of course I've also tried you guys suggest,
it doesn't work either.

Do you have any other idea how to fix it???

[joojaa]

Yes, but when you save it out form photoshop the straight alpha automaticaly gets multted in or rather its allwqwyas multed in form of another maya jsut sees it exactly asd it is without any convinence function to protect ypu. For all formats, Even the PSD tough photoshop automaticaly reinstates the state on load. So the CONCLUSION is taht this is EXACTLY your problem, thetis unless you actualy KNEW this before i told you inwich case you MIGHt have prepared the image differently. Somehwo because yoru asking i have a feeling you didnt know this.

you can straighten the alpha bofore you save tough using something like the action found here! what it odes it flattens the image so that the uatomatic multting gets overriden with one whare you say how to do it.

It does not realy matter that you didnt paint any color in phhotoshop paints sone color in automaticaly allways theers no such pixel available that has no color and is totaly trasparent just 4 channels, thet are represented to you in soem way to make you noet care. NOw the factthat in photoshop you dont understand this is of no concern to maya since you can actualy use this functionality to great effect.

Anyway its clear form teh swatches thet it realy is multted against gray. tis said ps should have unmulted layers but they might be multed too, its totaly hidden form the user. (so you dont know what thje case is, wich can eb abad thing)

[drblacksnake]

if you could post the scene and at least psd for color then I'd gladly test it, because I just tried both - masking and cutting - for transparency, and it worked without fringes.
also try to add textures one by one - I'm suspicious about bump.

[jtk77]

also try removing filters, set it to none, on your transparency pic. Sometimes the compression..like mipmap..ect...bleeds into the pixels surrounding the edge of the color change.
However, the comments in this post are correct, I would sugggest looking into what Joojaa has said further.

[joojaa]

ok i think this warrants a afurther and better explanation on alpha alpha nterpretataion comes in 2 flavors. Straight and premultiplied. Both have their respective advantages.

HOwever theres a 23nd factor thet plays in, its called a fringe effect. it often happens to people who carelessly use a imaging application like photoshop, first photoshop does not allways color the transparent pixels white but it rather depends on your bg color. thsi can bleed in the mipmapping stage.

Or in masking se the fact that you have straight alpha does not eman you picked up teh fringe during masking stage, now the defringe operator can try to kill this to you.
The default ttarnsparent background grid representation in ps is bad for contrast reasons, so for anybody i suggesta fully colored layar underneath, try a few fcolors to see the fringe it can be deleted later.

Now theni suggest you do flatten the images one by one and straighten them with the action onto black, thisway you get a better feel to how it works before you prceed into this subject.

[cah8222]

Thanks a lot for these suggestions.

It's really weird that Maya allow psd net work, except transparency.

I made one more image (a flatten Jpeg image) only for transparency.
The rest are all the same.
Then, it looks fine now.

I always thought this psd net work thing is awesome,
but it seems not perfect yet.

Thanks, you guys do help me a lot..........

[joojaa]

Yes well atelast form your swathes its 100% sure its afringe thing. fix your firnging. I suppose they are jsut a amsak channel and the colro one.

Ye that would be the rpoblem bad design. Nothing wromg in thatcase with mayas ability to convery the message maya conveyed it exactly like you told it. Its just you dont neccceserily underatnd what it is yru saying to maya. To darw the conclusion is broken is under theese circumstances a BIG mistake on the long run. So invest time in uderatanding this.

PS. ditch the jpeg... ist not a aformat you want to use ever for anything except your final image (because its lossy), thsi is something realy basic in image manipuletions that jpeg is the intermediary format for any cg.

PPS im not defending maya here im jsut telling teht theres a high chance your desogn initself is flawed by design (yes yes it may not looklike it to you but thst still common enough i se pro photshop users doing this mistake all the time jsyt bacause they never realy nee dto think about thiskind of stuff because they dont happen to necceserily se the problem on a dirthered print), this si not a falw either s a design after all teh fringe MIGHT be what you intended, just because 90% of the time 90% of people dont wnat a firnge does not eman its not better tools work like tye are supposed to isnetad of inventing new ways of craping thinsg up (this is teh sort of thing that can be automated as well as auto whitebalance, mind you if you can crack autowithebalance that never is wong your a rich dude. I could easily find someone to buy it form you for say 1 mil dollars, if you cas ensure it works in 99.999999% of cases)