World Pictures

[Ashenvale]

Holy crap. I had no idea how much I don't know.

Last week, a sci-fi RPG publisher asked me to create a planetary map and a continent map for its upcoming publication. I've been thinking in two dimensions with Photoshop as my tool.

Spinning planet video never entered my mind.

I feel something like I did when a sci-fi author friend first handed me Stephen L. Gillett's World-Building; A Writer's Guid to Constructing Star Systems and Life-Supporting Planets. There's are simple formulas for escape velocity? Tidal braking? Binary star system's gravity? I'm so in the dark!

[RobA]

Last week, a sci-fi RPG publisher asked me to create a planetary map and a continent map for its upcoming publication. I've been thinking in two dimensions with Photoshop as my tool.

You really don't need to worry about the nasty details of world building, as almost anything can get explained away by hand-waving. The real trick is to realize the polar distortion that occurs. Because of that, I like to work on base world maps using a vector tool to get the shapes correct when mapped to a sphere, otherwise the whole "greenland looks bigger than south america" problem starts to rear it's ugly head!

I think that is why many of the scifi mappers like to work on triangular/hex based projections of planets...

-Rob A>

[selden]

What does that histogram analysis look like on an Earth-derived heightmap?

I don't know.

Can you provide a pointer to one that I can try? A quick Google search turned up ways to get heightmaps of regions (e.g. http://www.tt-forums.net/viewtopic.php?f=29&t=27052 ) but I haven't found a complete one yet.

Whilst it looks bad on the histo, it is supposed to be a 16 bit PNG so its a smallish section of 65K levels instead of 256.

That's one of the problems that I realized when I woke up this morning. I guess I'm going to have to write my own utilities to do the kinds of manipulations I want to do to the height values.

Do you know what scale factor was used when the translation was done between the altitude and the 64K binary values?

I'm guessing that the large spike is due to the coastal regions of the continental shelves, so presumably is near 0.

[waldronate]

I don't know.
Can you provide a pointer to one that I can try? A quick Google search turned up ways to get heightmaps of regions (e.g. http://www.tt-forums.net/viewtopic.php?f=29&t=27052 ) but I haven't found a complete one yet.

I don't have a link to a good PNG heightmap, but I used Wilbur to read the ETOPO2 data and write out an equal-area 8-bit heightmap based on that data set. The histograms for each area shown below. The hump to the left is the oceanic abyssal plain and the big spike is the coastal plain/continental shelf. A straight histogram on the Plate Caree projection of the original ETOPO2 data set has some artifacts as shown in the second one (that hump off to the right in the plate caree projection is due to polar distortion for Antarctica, most likely).

[Nate]

So the focus area is meant to be Europe-like in location/climate?

[Antonymph]

Liking these!

[Vellum]

Whew!! I've been reading bits and pieces of this world building thread stuff. Dang have I got a lot to learn MUHAHA. You guys are doing a great job!! This is some far over my head atm I couldn't even do a simple layout in one of the map grab sections and be at the right scale LOL. this has been an enjoyable read tho.