View Full Version : Techniques for extending diffuse color beyond alpha boundaries

09 September 2010, 06:14 PM
I'm looking for an easier technique in Photoshop (or plugin) that extends the color of a diffuse map past the boundaries of the alpha channel for game art, so that if the color outside the alpha boundaries bleeds in at a distance, it won't create a halo around the edges.

The way I usually do this is just to do a few successive blurs on the original image (game-ready asset on the left, visualization with alpha applied on the right):

I've tried creating a Photoshop Action for this blurring method, but I find that this method needs to be catered individually to each asset due to different sizes, so I can't trust an Action to do the right thing every time.

But I've also seen some programmatically-created billboards that have this streaking that moves outward from each edge (these were created in Torque Game Engine Advanced using SpeedTree):

So, would anyone like to share the way they handle this? I'm looking for a quicker and more universal way than my current blur method.

09 September 2010, 07:49 AM
Have you tried Solidify by Flaming Pear?

It's free here in the Free Plugins pack about halfway down the page.
Three version with slighly different results.

09 September 2010, 03:06 PM
if you have Photoshop CS5, do it with content aware fill and a thin selection. The quality is very good and only needs minor touchups. This gave me a good reason for a blog post, which explains/shows it here, with a PS CS5 (only) action:

09 September 2010, 12:19 PM
You can always apply Filter > Other > Minimum (set to 1) to an underlying layer copy of your clipped image to expand the edge. Next, lock the underlying layer copy and apply the Maximum ĎOtherí filter (set to 1) to reverse the slight dark area spread caused by the Minimum filter. The filters are available with all previous versions of PS that Iíve used.
I use this technique, for example, when I need to float raster elements with clipping masks over colored backgrounds in Illustrator.

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09 September 2010, 12:19 PM
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