I saw this much later after this last post.
Two things. It turns out that you can actually use an overlay as the map itself. I haven't done it, but Vic mentioned it in a reply:
tm.asp?m=2957517
I haven't tried it.
As for graphics, using something like GIMP is great. You can easily load the image and then select an area that would scale to 128x96 (BIG) or 64x48 (normal). Save this, and then crop to the ATG hex. For this, there are two ways. One is to just use the magenta hexes, paste in, and then select the color, and delete it (be sure to add an alpha channel first). Or add a layer mask, and make a black and white image of the hex (black is transparent and white is opaque). Add a layer mask, and paste the black & white image into the layer mask. The warning is that if you make the 128x96 hex first, it doesn't work well to shrink down as the program will tend to blend the edges, and the 64x48 hex will look bad. It is better to shrink the full 128x96 hex and then add the 64x48 hex layer mask. Another problem is that you may find that to get the image you want into the 64x48 size, you will have to shrink it so much you lose detail and it may not look that good.
Now, the real trick is to make a hex that tiles. Otherwise you get a map where there are obvious mismatches on the edges for even the same terrain type. It looks like crap as you have a repeating edge. The problem is that you need the N and S faces to match, while at the same time the NW and SE and NE and SW faces have to match. For the ATG hexes, this means that the graphics have to repeat (for the BIG hexes) 106 pixels horizontally, and 48 pixels vertically. This basically tells you how to do it, but for a good tiled hex, there are two steps.
First, make a 106x48 image so that it tiles. Then create a transparent 212x96 image. Paste your 106x48 image into the center. Then along its edges, paste the image to fill the 212x96 image. Now if you crop this image to 128x96 anywhere, and then mask to the ATG hex, i.e. transparent edges, you will now have a hex that will tile in ATG. For 64x48 hexes, just divide by 2.
That doesn't quite finish it though. Because, while it will tile. It will also repeat you image every 106x48 pixels, which will lead to some heavy patterning. To fix this, you should merge another image into your tiled image. This can be done with a fuzzy layer mask, which is a pretty standard trick to merge two pictures. Create two layers, say the bottom is the tiled image, and the top is the center. Now, create a 128x96 black image (black will be transparent). Draw the outline of the main area in white, fill with white. Then do a Gaussian blur with a 10 pixel width or so. Go back to the top layer, add a layer mask, and paste the fuzzy black & white image into the layer mask. Now, the edges of the top layer will be transparent and should merge into the image in the layer below. You can adjust the level of the transition with the size of the blur. Then, by making an image from visible, you have a unique 128x96 image that is hex tileable.
One man alone can be pretty dumb sometimes, but for real bona fide stupidity, there ain't nothin' can beat teamwork -- Edward Abbey
