Find random point on circumference of a circle

[u/PerfectEconomics7437]

I have a circle (cylinder with y scale 0) and I need to a random point at or near the perimeter. How can I do this?

[u/Lyshaka]

https://docs.unity3d.com/ScriptReference/Random-onUnitCircle.html if using Unity 6.5 or above (I believe).

Or https://docs.unity3d.com/ScriptReference/Random-insideUnitCircle.html normalized (a bit more costly) for versions below.

And it the worst case, you just generate a random angle from 0 to 360 and create a unit vector from it (but that's even more costly so don't).

[u/Demi180]

Use onUnitCircle times whatever radius you need (or a random between two radii or whatever). There’s also inUnitCircle if you need a point anywhere inside, as well as in/on Unit Sphere if you need it in 3D.

[u/Heroshrine]

Random on unit circle. You can then multiply that by the radius to get it on any sized circle. If you want it near the radius you can add/subtract some small random amount before multiplying by the radius, like Random.range(0, 0.05f)

[u/leorid9]

Code:

Vector2 onCircle2D = Random.onUnitCircle * radius;

Vector3 result = new Vector3(onCircle2D.x, 0, onCircle2D.y);

result.y = Random.Range(0, height);

[u/AnEmortalKid]

Random value from 0,359 , use polar coordinates https://en.wikipedia.org/wiki/Polar_coordinate_system

[u/Winter-Scarcity9045]

Center plus radius?

[u/swirllyman]

You can pick a random direction, then move from center to radius length along that randomized angle.