white fringe on images with opacity maps

[andrewxgoodman]

I’m using Max 2010 with mental ray. When I include a 2d surface - a billboard for an entire plant, or for a leaf on the plant - with an alpha mask I get a one pixed white fringe around the image. I’ve tried all permutations of alpha channels and external grayscale maps. I’ve had this problem with many images from many sources in many formats, and I’m sure there is not a white fringe in the original color file. If there was a fringe in the original file, then the fringe would vary in size. But zoom in or out, increase or decrease the render resolution, put a light or a dark background behind the image, and I still get the one pixel fringe.

Help!!

[YOHKOH]

Hi

 

Turn you blur on opacity maps and diffuse image to 0.001

 

Should do the trick.

ta

[jinsley]

I think the "white fringe" is a slight difference in the diffuse and opacity map not lining up perfect. or the opacity map has not been done very well.

 

1. take the diffuse map into photoshop

 

2. use the oppacity map in the alpha channel (create new alpha layer and past in the black and white opacity map) to make your selection and duplicate the layer.

 

3. use a slight gaussian blur ( 1 - 3 px) on the lower image. This will help the diffuse map bleed out to the edge of the opacity.

 

4. turn off filtering on the diffuse map and opacity map to get nice sharp results.

[bnorto2]

My guess is you have the default "Pyramidal" filtering checked in Bitmap parameters. Try going with "None". In "Pyramidal" max tries to smooth the alpha channel where it goes from black to white, so you get the extra "gray" buffer between the two. At least that is what it usually is for me when I see that problem.

[andrewxgoodman]

Yes! The blur did the trick. It also works at 0.1. Much thanks, I've struggled with this for a while.

[andrewxgoodman]

And Pyramidal also did the trick. Thanks again!