Planet Orbits

[drifting zodiac]

This is probably happening, it’s velocity moves it to a position outside of orbit

@hallow trout

I did attempt Simferoce’s idea, since it also works out mathematically but it has the opposite problem where the planet actually starts moving towards the sun.

I could’ve did something incorrectly since I was in a rush, but my guess was that it created a velocity that moved the object inside the orbit

[drifting zodiac]

The only ideas i have are to either

• Use a hinge joint to physically constrain the planet to the sun so it doesn’t move out of range. https://docs.unity3d.com/ScriptReference/HingeJoint.html
• Use what you have already but apply a clamp on the distance every frame

Vector2 dir = (sun.pos - planet.pos);
planet.position = dir.normalized * fixedDistance;```

Actually you might also be able to do some fancier math that creates a vector to move the planet to a point on the orbit by the next physics timestep.

[drifting zodiac]

Vector2 dirToMove = new Vector2(5,0);
rb2d.velocity = (dirToMove.x/Time.fixedDeltaTime, dirToMove.y/Time.fixedDeltaTime);```
This should cause the rb to move at 5 units per **frame**. If you can calculate the next point on the circle to move to, you can generate a direction to that and the rb should in theory be at the position on the next frame

[hallow trout]

Ah clamping the distance is a great idea, i’ll try that out when I get home!

[drifting zodiac]

by far the easiest solution, hopefully that’s enough 🙏

[hallow trout]

This sounds effective but Im curious as to how that would work in making the planet rotate in a circle rather than a straight line

[drifting zodiac]

The idea would be to calculate a point on the circle to move to, and then plug in a velocity that would move the planet to that point in 1 physics frame

instead of generating a velocity to a point off the circle

[hallow trout]

I really appreciate it, I’ve just been trying a ton of different ways orbiting planets in a solar system so these ideas are super helpful

[drifting zodiac]

good luck on your project! 🍀

[hallow trout]

Thank you!

[hallow trout]

Oh right, I think I can manage that. Though I might have to whip out my old notes from Pre-Calc 😅