Hello everyone. I am creating my own collision algorithms and noticed that some values are not exactly what I was expecting. Seems like a bug.
I created a sphere and was expecting that it’s boundingSphere had the same (or at least a close) value.
The sphere has: diameter = 1 but the boundingInfo.boundingSphere.radius = 0.8660254037844386
Seems to be out by a factor of sqrt(3)
Hello! I understand where the confusion comes from, but the boundingSphere is actually bigger than what you’re thinking, as its constructed directly from the minimum and maximum: Babylon.js/boundingSphere.ts at master · BabylonJS/Babylon.js (github.com). In this example, the min is (-0.5,-0.5,-0.5) and max is (0.5,0.5,0.5), when you get the distance between these two and half it, you’ll see it matches the 0.86 radius 
Sorry but (0.5, 0.5, 0.5) - (-0.5, -0.5, -0.5) = (1, 1, 1)
Half this and you get (0.5, 0.5, 0.5)
It’s distance, so sqrt((0.5 - (-0.5))^2 + (0.5 - (-0.5))^2 + (0.5 - (-0.5))^2) = 1.73 
This may help debug and understand what’s going on Drawing Bounding Boxes | Babylon.js Documentation
EDIT: To be clear, as @carolhmj mention, the results seem correct, it’s just that the corners of the cube will stick out of the sphere and you’re comparing a diagonal that is larger than the diameter of the sphere. If you compared the distance at the middle point of the cube faces, you’d get the same as the sphere
Sorry you are right its across the diagonal not just the difference.
Thank you @carolhmj makes sense now!