Universe Sandbox

Universe Sandbox Legacy => Universe Sandbox 2008 | Help => Topic started by: Magnetar on September 01, 2009, 05:47:08 AM

Title: Gravitational tools not showing up
Post by: Magnetar on September 01, 2009, 05:47:08 AM
Hi I wrote a system. However when I turn on the gravity related tools like Relation Lines, Hill Spheres or Lagrange Points they are not showing up. However when the objects of my system crash into each other and melt together these tools suddenly begin to work for weird reasons. I compared my system with various save games I made and other systems but I don't see anything wrong in it. Any suggestions what might have gone wrong?
Title: Re: Gravitational tools not showing up
Post by: atomic7732 on September 01, 2009, 07:47:21 AM
You might want to upload the file.
Title: Re: Gravitational tools not showing up
Post by: Magnetar on September 01, 2009, 09:19:21 AM
There it is.
Title: Re: Gravitational tools not showing up
Post by: Dan Dixon on September 01, 2009, 01:05:30 PM
You're doing nothing wrong.

Relation Lines, Hill Spheres, and Lagrange Points all require a body to have a "parent" body in order for the calculation to make sense. Since all 4 bodies are the same mass there is no "parent" body which is why none of the tools show up.

This is also why they work once they crash together, because the new body can be the parent of the remaining bodies.

I need to do a better job of communicating this situation in the program.

Title: Re: Gravitational tools not showing up
Post by: Chaotic Cow on September 02, 2009, 07:28:20 PM
Ooohh..I always wondered why Hillspheres never showed on Earth in the Earth & Moon.

Good to know and makes sense.
Title: Re: Gravitational tools not showing up
Post by: Magnetar on September 13, 2009, 04:20:12 AM
Ok, thank you for telling it to me.
So this basically means that masses have to be different, in order to make one object considered as parented.
I originally thought Relation Lines were just based upon detecting the attractor which creates the most force on the satellite.