I'm working on my own tile-base isometric engine, and came to this philosophic question: which way is better?
a) Make map from hexagonal tiles (the way I'm doing it now)
b) Make map from square tiles and then overlay hexagonal grid over it (the way it is done in Fallout, for example).

First way is simplier when it comes to determining blocked hexes on map: each tile has CAN_PASS flag, so if it is not set, player can't walk here.

Secon approach is simplier, because it's easier to create square tiles that hexagonal tiles. But then, I need to map square tiles to hexagonal grid to check for passability.

I'm sure that both methods have some other troubles connected with them, and I need some advice to choose one. Express your opinions on this topic, please.

P.S. It seems that every map cell in Fallout consists of at least three bytes: tile number, wall number and can pass/cannot pass flag. Am I right or wrong about this?

Overlaying the Hex tile is ever so much easier. Drawing seamless hex tiles can be a real pain when it comes time to do something complicated. It's not too difficult to do hex deserts or plains using a program like Reptile, but that only works when its difficult to see the edges anyways. Try drawing a building or more complex ground cover using hex tiles... augh...

Depending on the size of your map, you could also ignore tiles altogether and simply opt for a pre-rendered background. If you use OpenGL, you can usually get away with using a quad that is 50% bigger than the pre-rendered texture background and still have it look nice. For my hex-based game, I don't use tiles at all and it works remarkably well.

Hex Overlay
Hex Overlay 2

If it turns out for some reason you do insist on drawing authentic hex tiles and your tiles are in a ratio similar to mine, let me know because I have a bunch of old tiles you can have that I made before I switched to pre-rendered backgrounds.

Thanks for the compliment... Hopefully it will be finished someday;D

Of course seeing things like:
Heroes 5
It gets a little depressing. My game isn't a Heroes clone though and is more like a hybrid of Heroes and Magic the Gathering, so there's still a chance I can win on the gameplay front.

Thanks for your responses.

Diamond-shaped tiles are OK, but still, I'll need to overlay hexagonal grid over them, because square grid is evil (for RPG).

I'd say "no". I'm not good enough with Photoshop and it's hard to find a designer for free these times It's a bit easier to design level from tiles, I suppose, though it will look a bit duller (anyway, Fallout rules and Baldurs Gate sucks ).

I'd say I'll use diamond-shaped tiles then with overlayed hex grid.

Hey, cheer up! GFX isn't what makes a game great! I'd vote for Master of Magic over Age of Wonders any day of week.

BTW, I've attached a screenshot of what I have now in my engine (so far, it uses hexagonal tiles).

Oh teh noes! Your using the wrong type of hexagons

If you decide to use the correct type of hexagons, here is part of my old tile set:
Hexagon Tiles

You (and everyone else) are free to use these tiles in any commercial or freeware project you desire. Don't even have to give me credit. If you get a good demo, I might even be tempted to create some more...

In case you want to make your own, I highly recommend the free version of Reptile (1.0) from Sausage Software. Make a bland/generic texture that is easily tileable and then in a paint program, play around with the brightness and contrast. Once you have a nice base, save a bunch of copies and use the color dodge/burn tool to add variety. I kind of like how a lot of my hex tile set turned out, but then I like pre-rendered with hex overlays even more:)

In Xcom its possible to move in eight directions. Of cource, diagonal moves are usually a bit more costy in some circumstances.

I'm quite positive threre would heve been several bigger and a bunch of smaller problems to solve, just like in any kind of game/engine.

Oh, OK their orientation is different...

BTW, I came up with "brilliant" idea: what if I'd make (have someone make) pre-rendered map of territory (without accesable building, which sould be constructed from objects, not tiles) and then approximate it with tileset to save disk space and memory? I.e. if large part of pre-rendered map is filled with grass texture, let's make a several "grass" tiles and use them instead. Ofcourse, this way we'll have separate tileset for each scene and there will be some quanity of "unique". Oh, well, I'll need a good algorithm to compare two images then. Does anybody know one?

EDIT: tried naive algorithm of comparing pixel-by-pixel HSV-wise. The best result is 88 40x40 tiles instead of 300 (if every one was unique) and not very distorted image... 1/3 compression doesn't seems very bad, but it was only 800x600 pixels bitmap. So think: if location is REALLY big (like, 10x10 screen sizes), I'd have 8800 tiles agains 30000 without "compression". That's still bad enough, though, because 8800 40x40 tiles in png would take A LOT of space, and BTW Fallout ONLY has 1600 tiles for ALL locations!! Gotta think harder...