How can I get an perfect east-west straight track?
Started by SanDiegoMark8 posts8 min read
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I am extending my San Diego and Arizona route from Coyote Wells to El Centro. From Plaster City to El Centro, the line appears on the maps to be exactly 90.00000 degrees east-west.I tried using F4 to rotate a straight track but there does not seem to be a way to ascertain that the straight is rotated 90.00000 degrees.I am looking for hints on how to get that first straight piece right on.I considered:1. using F4 and eyeballing it but after a couple of miles, I see by using F7, that the track is not east-west. I tried this several times and I don't think I could ever get it exact.2. placing a piece of straight track with F5, expecting that it would be exactly north-south and then using 9 of the end point 10d left curves to get a quarter of a circle of track. Then put a straight piece on the end and delete the curves. This seems like it should work.Is there some other better way? Maybe editing the track data base or world files?
Mark DiVecchio markd@san.rr.com San Diego and Arizona Railroad
RE: How can I get an perfect east-west straight track?, markhyams, Sep-24-02, 03:03 AM, (1) RE: How can I get an perfect east-west straight track?, mivone, Sep-24-02, 03:04 AM, (2) RE: How can I get an perfect east-west straight track?, osmyrl, Sep-25-02, 03:15 PM, (5) RE: How can I get an perfect east-west straight track?, mivone, Sep-25-02, 11:00 PM, (6) RE: How can I get an perfect east-west straight track?, Kip, Sep-24-02, 03:10 AM, (3) RE: How can I get an perfect east-west straight track?, jleslie, Sep-24-02, 08:46 AM, (4) Follow Up, SanDiegoMark, Sep-26-02, 11:46 PM, (7)
RE: How can I get an perfect east-west straight track?
Your method 2 should be accurate!As you guessed, you can also work through the world tile files, as follows (this may not be quicker, and should be about equally accurate):- place a straight track section where you want to start your east-west track (its orientation does not matter for now);- save the route;- find the world tile file (in the route's WORLD folder) that corresponds to the tile where you placed the track section (if you place the camera near that track section, the camera's "tile x" and "tile z" will tell you what you need);- open that world tile file (with a Unicode-capable editor) and find in it your new track section, by searching for its Position coordinates (you know its coordinates by selecting the track in RE, so the Object window displays its x, y, z coordinates);- right below the Position line of the object, you will see a QDirection line, which by default looks like this:QDirection ( 0 0 0 1 )(the 0 0 0 1 defines north in MSTS);- change that line to readQDirection ( 0.000000 -0.707107 0.000000 0.707107 )for straight east, or QDirection ( 0.000000 0.707107 0.000000 0.707107 )for straight west (the difference between east and west won't matter to you);- save the world tile file;- reload the route (with track database rebuild if this reorientation changes any connections between tracks).This reorients that track section to be exactly east-west. Michael Vone Step by Step Guide to Route Building for MSTS - http://trainsimulatorworld.com/catalog/b470.htm Albula Line Route Rocky Islands Route Cliff Hanger Route http://avsim.com/hangar/utils/mvchallenges/
RE: How can I get an perfect east-west straight track?
No disagreement at all with the "QDirection" method, but I'm curious as to what the four fields represent. The value you gave for two of the fields (0.707107) is approximately half the square root of 2. How dows that relate to one of the four directions? I'm sure it will be quite obvious when you explain it, but at the moment it doesn't seem to fit any pattern.
RE: How can I get an perfect east-west straight track?
Indeed, 0.707107 is half the square root of 2, which is the cosine, and also the sine, of half of 90 degrees (the desired turn angle).I also thought this should become obvious fast, but it took me a long time to figure out those numbers! (They are known in mathematics by the pretty name of quaternions: they are used a lot in computer animation and for orienting spacecraft and telescopes.) And what they mean is still not obvious! That is part of the reason that it is so hard to rotate objects in the Route Editor. However, once this was figured out, a lot of other things became possible.I am including the simpler cases in the next edition of my Guide (in a month or so), which will also have an add-on utility (using Excel) that will do all the math for you: it will allow you not only to accurately place an object in any direction you desire, but also to align two objects precisely (like bridges, platforms and fences along tracks), to create very steep tracks, to aim tracks straight to a distant location (even through mountains without digging a trench), etc. Important note: this tool will not be simple and quick! It will be for the advanced route builder!Michael Vone Step by Step Guide to Route Building for MSTS - http://trainsimulatorworld.com/catalog/b470.htm Albula Line Route Rocky Islands Route Cliff Hanger Route http://avsim.com/hangar/utils/mvchallenges/
RE: How can I get an perfect east-west straight track?
LAST EDITED ON Sep-24-02 AT 03:21 AM (EDT)
Try this...works for me.Place the straight piece of track on the ground. It should automatically point 0°/360°. Now...press F2 select the track, press F4...go to the placement window and click the grid box. Don't use the mouse here...hold the "END" key and hit either left or right arrow key on the numeral pad. The track will move in uniform every 45° every time you hit the left/right arrow keys while holding the END key. You should then get a perfectly laid piece of track at 90°. Sometimes if you do this the "grade" of the track may dip. Click off the grid box and with the mouse raise it back to zero or what ever "grade" you need. It usally stays at 90°. Give it some practice. Kip 3DTS Route Developer The Priest River Railroad"...it's so fictional, it's almost real" PRRR WesiteComing this fall: PRRR's Hoodoo Pass Route
RE: How can I get an perfect east-west straight track?
Here's my method of eyeballing it with my calibrated eyeball:1. Hit the "W" key to get the wireframe terrain grid.2. Rotate the track piece normally using the "4" and "6" keys on the number pad.3. Notice that the grids run 0 - 180 degrees, 45 - 225 degrees, and 90 - 270 degrees. Rotate the track piece and eyeball it so that it lies parallel to the E-W lines. I can usually get it pretty close, but then I'm not running 200 miles of track at exactly 90.00000~ degrees either. The 5 decimal points you have above is 1/100,000th of a degree by the way....I don't think even the Union Pacific can run that perfect of an azimuth.My method works fine for short distances, but over many miles any error can throw you off quite a bit.If you want perfection, you will need to use one of the above mentioned methods.Jeff Leslie
Thanks to all for their suggestions. I wanted a line running really east west because out in the desert of Imperial County, irrigation has changed the desert into farmland. I wanted to make a terrain texture of the typical farmland with rows of plants. I saw out there that the rows of plants and the irrigation ditches were everywhere perpendicular to the rail line. In order to get the rail line and terrain texture to keep the right orientation, the rail had to east-west within a small error over distances of 20-30 miles.So I tried each suggestion and then checked the World File.I found that the two ways that got me exact east west track were: 1) my number two suggestion in my first posting and 2) Mike's suggestion about editing the World file.As a matter of fact, the QDirection line ended up the same for both ways.Mike's suggestion of editing the World file was quicker but for those who might not want to touch that file, using a north-south straight with 9 EndPnt curves gave the same result. When I tried Mike's method, I used a tunnel section to make it very easy to find the track section in the World file. After the edit, I attached a standard straight and deleted the tunnel section.Thanks for all the suggestions.
Mark DiVecchio markd@san.rr.com San Diego and Arizona Railroad
