## Mapping the Stars

Originally, this was going to be a post on populations inspired by this post on Sword vs Dagger. Unfortunately, that has expanded, so far into about three posts. This will be one of those posts, although only tangentially related.

I’m going to speak today, as the title implies, of the mapping of stars. My tools will be the Extended Hiparcos Catalog Search Page, and ChView2. For further information on the use of the Hiparcos search page, look at Stellar Mapping and How to Make Your Own Stellar Database by Constantine Thomas. Some information on Chview2 may be found at Solstation, but it’s not terribly well documented. For the most part its a pretty simple app, and a lot of the instructions for the original ChView would be applicable. It’s a dandy little app, and very useful, but it still has a few bugs. I’ll try to help my gentle reader over those.

The empty main screen of ChView 2.

We’ll start simple and work our way up. Once you have a copy, double click on the chview2.jar. Our introductory project will be to make a sort of compass rose. This will introduce most of the basics needed for using ChView2 for starmapping.

Right click anywhere in the main view window(the black area at the bottom of this

The screen for editing fixed objects(in our case, generally, stars).

picture), to bring up a contextual menu. Select “Add Fixed Point” from the top of the menu. That will give you the “Edit Fixed Object” window as shown. Enter, “Origin,” as the Common Name, which is what will show on the map display. Set the Technical Name to, “(0,0,0).” Use the pull downs to set the Style and Class to, “F Star,” and, “Star.” Finally, leave the Coords, X, Y and Z as 0, 0 and 0. Hit OK. That gives you the “Origin” point for the Compass Rose.

Similarly, make a point, “+X,” at X:9, Y:0 and Z:0(9,0,0), “+Y,” at (0,9,0), and, “+Z,” at (0,0,9). Set the Style and Class of these to, “G Star,” and, “Star.” The resulting map should look a bit like this.

Our 3d compass rose in ChView’s default view orientation.

So what can we see here? First of all, we can see that ChView has a rather odd orientation by default. I’m not quite sure what that’s all about, but I’ve seen a lot of weird axis definitions in computer stuff. We can fix that readily enough, but first I would like to introduce the various buttons, sliders and other tools that ChView 2 places readily to hand.

First of all, let’s look at the rotation controls. These are the three sliders in the first bar beneath the menu bar. As shown in the image to the left these bars control, from left to right, rotation around the Z-axis, the X-axis and the Y-axis. My own copy of the program includes a, “zero,” button for each axis to return the rotation to default value. Until and unless I can get permission from ChView 2’s creator to put up my own version that won’t be available generally. If I do get permission to put up my own mod of the program, I’ll likely replace that with a numerical input field, instead, so ignore that part anyway… Play with the sliders to get a feel for them. If you have the compass rose entered, that can be a guide to help you orientate.

The next element we’ll look at is the toolbar below the rotation controls. These tools vary considerably in their usefulness. I don’t generally use the time controls for much, so I’m going to kind of gloss over those for the moment. Suffice to say they operate similarly to the VCR/DVD controls they somewhat resemble and they’re pretty readily understandable with a bit of playing around. The scale controls, which I neglected to label, lie between the printer icon and the grid display toggle. These are also fairly easily understood with a little playing around. The printer icon is actually useless. Print facilities have not yet been implemented in this program.

A quick digression into terminology. In ChView-speak, routes are special objects intentionally placed between fixed objects on the map. They represent geographic relationships between the connected objects, for example, as the name implies, routes between those objects. Links are automatically-generated lines between objects, that give a sense of the distance between the objects. Links can, in fact, be labelled with the distance represented. In any case, links will be colored differently based on the categorical distance represented. Lets open the Preferences panel and look at the Links tab.

The settings here are a little different from my previous compass rose image. I’ve decided to show numbers on the links. This isn’t actually all that useful on a compass rose, but it can be of great utility for close-in work with starmaps. Once you get far enough out, the numbers(which describe the distance represented by the link) can muddy up the map to the point of incomprehensibility. The top input field allows the user to set the shortest link length that is desired to be shown. The top line style will be shown for all links with a length between that minimum and the value entered in the next field, and the next style will be used for links of length between that value and the one entered in the next field and so on… The field at the very bottom represents the very longest link that will be shown. A very long maximum length will result in a very busy map that could take a very long time to redraw if there are a lot of bodies. That last value also sets the maximum individual step allowed when using the route finder(Main Menu Bar>Report>Route Finder). The route finder is of great utility in figuring out distance-limited routes between objects on

A picture of the final compass rose in a good orientation. Also shown are the tear-off toolbars.

the map. The route selected isn’t always the minimum path between two objects, but the deviation from the minimum path is usually pretty obvious.

After unchecking, “Show Numbers,” again, this next image shows what the properly rotated compass rose looks like. This also shows the tear-off toolbars in action. I’m not sure how useful this feature really is, but hey. You can redock the bars as you wish or simply click the dispel button and they will return to their previously docked location.

As you can see from this image with the compass rose, an orientation with the z- and x-

axis rotations zeroed and the y-axis rotation screwed to the left or right edge of the bar, will resemble the common 3d page map structure of y as vertical, x as horizontal and z as out of the page. One could even imitate the style of map used in GURPS or Space Opera space atlases by adding a z-axis value to the common name of each Fixed Object. That would be no end of cool.

When creating new stars(Fixed Objects), if nothing is currently selected, the default

A test sector in the GURPS Space or Space Opera atlas style.

position of the new object will be (0,0,0), if one object is selected, the position will be the same as the selected object, and if more than one body is selected, the default position of the new object will be equidistant between the selected objects. You select multiple objects by holding down {shift} while left-clicking the objects. Try creating a few bodies. I would expect your map to look nothing like mine to the right. Have fun with it…

When you try to save this, you’ll run into a couple of problems. The first glitch is that the Save dialog is exactly the same as the Open dialog with no field to enter a name. You’ll also notice that there’s no obvious hint as to what the naming format is that it filters on. The second problem can be fixed with a quick look at the source code which is conveniently zipped into the jar-file. The format is “{name}.chv.xml”. The second problem is a real bug and it needs fixing. In the meantime simply use a text app like TextEdit or Notepad to create a file in the desired location, “{name}.chv.xml”. When in the broken Save dialog, you can simply click on the file you just created and ChView 2 will put the data into that file. The actual save routine is fine, it’s just the interface that’s bollux.

I forgot to mention another way to rotate the map. If you hold down the right mouse button and drag you can rotate the view about the z- and x-axes. Also, I forgot to put up a real pretty view with the grid toggled on. I rotated the view somewhat arbitrarily and hid the link lengths in order to minimize conflicts. The view is a bit odd, but it shows clearly the way the grid works. I selected all of the objects in the map and centered the view, thus the plane is a little bit below the z-zero point as the objects I placed are weighted somewhat towards the negative-z. I kind of wish, when doing this sort of thing, that ChView had a compass rose faculty.

Next time I’ll get into importing real-world data from existing catalogues, and using Chview 2’s tools to help with detailing your little patch of the universe.

I’ll leave you with some interesting links that might give an idea of where I intend to go with all of this.

Solar System Live by John Walker

3-D Starmaps by Winchell Chung

GURPS Traveller: First In Designer’s Notes(an inspiring Pyramid sample article) by Jon F. Zeigler

3D: Mapping the Solid Subsector(inspiring JTAS article[not free]) by Christopher Thrash

Internet Stellar Database by Roger M. Wilcox

The Division of Territory in Society by Ed Stephan

Medieval Economics by Philip McGregor

GURPS Architecture by Matt Riggsby

The Theory of Interstellar Trade by Paul Krugman

Low-Tech Economies by Matt Riggsby

Adventure Cargo and Interstellar War by S. John Ross was apparently useful to the designers of GT: Far Trader (GURPS Traveller).

Thank you for your attention. I hope this was as helpful to you as it was enjoyable to me.

The Astrographer