changing collider size avoids collision detection?

Hi All,

I’m trying to use the physics engine to simulate a traveling sound wave.
I’m using a sphere collider whose radius grows to match speed of sound.
The edge of the sphere is the wave.

Every FixedUpdate() the wave radius changes.
It goes through the target, engulfs the target.
NO trigger events are fired.

Bullet through paper not an issue?
I can see it intersect the sphere surface.
It would trigger the OnTriggerStay() once isside the sphere ?


triggers only recognize other colliders if they have rigid bodies

now ive always wanted to play with growing a collider however ive noticed that colliders can be real shit when it comes to reliability, ESPECIALLY when you get more elaborate in their usage.

You could try this though, it may take some work to be optimal
but there is physics.SphereCastAll
and you could just grow the sphere every measure of time

or you could use
which i believe is more efficient and looks for the bounding volumes of colliders it intersects.

using these would be far more reliable than doing what you are, Changing colliders can be finicky and take several fixed updates before they work right.

now unrelated to your question, if what you are doing is actually for sound in 3d space, they already have functionality built in to handle that using audio sources and listeners. You can even use them to handle code events.