Making a hex grid with Gimp???

[RobA]

I'm trying to modify some existing maps I have from some old role-playing games by over-laying a hex grid on top of them. I found this by searching the archives and it does pretty much what I'm looking for, except for one big problem: the Filters->Distort->Mosaic filter in GIMP can only go up to a size of 100 pixels, and I'm needing a much larger size due to the high resolution of the original map I'm overlaying a grid on. Is there any way to override or work around this limitation?

Here derio - I just wrote a script for Gimp:

[EDIT - attachment removed, an improved version of the script is now here]

-Rob A>

[mthomas768]

Another method is to use this site to make PDF graph paper and import:

http://incompetech.com/graphpaper/

It does a wide variety of graph papers, including hex.

[RobA]

Quick question -

I am cleaning up that quick script and will be posting it in the software forum...adding other features like offsets.

Right now you specify the length of a side of a hex (A in the attached).
hex.jpg

What is the best/most useful way... this, or point to point (B), or side to side (C)?

Or provide a drop list to select the item?

-Rob A>

[isomage]

For mapping I'd suppose that the center-to-center distance would be most useful; if you're specifying distance on a map, like "one hex = 8 miles", or the number of hexes per inch, that's what you'd be talking about.

Edit: I just realized that's "C" in your diagram...

[Korash]

Actually, I think that the dropdown would be best. People measure hexes differently depending on preferences.

I would also recommend placing the output on a separate layer and add a dropdown for layer mode. The reason for this is that I tried the script and found that it could be a problem if it is on a working layer instead of a blank one. Having it on a separate layer also allows for the differing effects available from the modes.

I like this script a lot by the way and thanks for the work you do with them

[derio]

Wow, you guys are awesome. That hex grid plugin works great, and is simple to use. I had the same issue with having to calculate side length A when I knew the wavelength C, but a bit of geometry took care of that calculation. Giving multiple options on A, B, or C is probably the most robust way of making the script, however B = 2A so including B is perhaps redundant.

However, I did notice that it's limited to 400 pixels for maximum length. That's larger than what I needed, but in general could it be modified so that there isn't a hard maximum length? i.e. make the maximum length be equal to the maximum dimension of the image, or just have it as an input field with no maximum (or at least a long int as the maximum...)?

[RobA]

Thanks for the feedback.

A cleaned up and functionally enhanced version of the script is now here:
http://www.cartographersguild.com/sh...ad.php?p=60475

@derio - you have to specify limits in a script definition. I picked 400 just because it was a nice number

-Rob A>

[derio]

Also, while I was google searching for other ways to get around this problem, I found this program: mkhexgrid. It looks like the author was envisioning it as a program for generating labeled hex grids like those used in Battletech, but it's customizable enough that you can do a lot with it.

I wasn't able to generate a grid with a transparent background, so I used color select to copy the grid and paste it onto a transparent layer.