How to keep view static as time increases

[twaclaw]

I am trying to create a script that illustrates the Earth's (and other planets') movement around the ecliptic. In my script, I display the constellations of the zodiac and the ecliptic line, and I set the observer's location to the sun so that I can see the Earth.

Is there a way to set an observer location where the zodiac remains static as time increases? Alternatively, is there a way to counter the rotation so that the view of the background sky (the zodiac constellations) appears static while the Earth moves from one constellation to another?

Ideally, I would like a static view of the Zodiac constellations while the planets move around them over time.

[gzotti]

As long as you have no object centered, there should be no rotation when you have selected "telescope" (equatorial mount) mode (Ctrl-M).

[twaclaw]

core.setMountMode("equatorial"); made the trick.

Thanks a lot!

Suggestions / improvements welcome.

Here is the script for reference:

Click here

include("common_objects.inc");
var constellations = new Array("Twins", "Crab", "Lion", "Maiden", "Scales", "Scorpion", "Serpent Bearer", "Archer", "Sea Goat", "Water Bearer", "Fishes", "Ram", "Bull");

var delay_between_constellations = 0;
var time_step = "+1 day";
var time_step_delay = 0.1;
var atmosphere = false;
var initial_fov = 288;
var n_iter = 365;

core.setGuiVisible(false);
LandscapeMgr.setFlagCardinalPoints(false);
LandscapeMgr.setFlagLandscape(false);
LandscapeMgr.setFlagAtmosphere(atmosphere);
StarMgr.setFlagLabels(false);


core.setDate("now");
core.moveToRaDec("17h 53m 0s", "88d 25m 0s");
core.setSkyCulture("modern");
StelMovementMgr.zoomTo(initial_fov, 1);

ConstellationMgr.setConstellationDisplayStyle(1);

ConstellationMgr.setFlagLabels(false);
ConstellationMgr.setFlagArt(false);
ConstellationMgr.deselectConstellations();
ConstellationMgr.setFlagBoundaries(false);

SolarSystem.setFlagLabels(true);
StarMgr.setFlagLabels(false);


var loc = core.getObserverLocationInfo();
core.setObserverLocation(0, 0, 0, 1, "", "Sun");


ConstellationMgr.setFlagIsolateSelected(true);
ConstellationMgr.setFlagArt(true);
core.setMountMode("equatorial");

for(i=0; i<constellations.length; i++)
{
	core.selectObjectByName(constellations[i]);
	core.wait(delay_between_constellations);
}


for(i=0; i < n_iter; i++)
{
	core.setDate(time_step);
	core.selectObjectByName("Earth", true);
	core.wait(time_step_delay);
}