How to CastRay() for Unity.Physics.SphereCollider struct without SphereCollider.Create() factory method call - unity3d

Question

How to CastRay() for Unity.Physics.SphereCollider struct without SphereCollider.Create() factory method call (resulting in heap allocation I presume).
Code below doesn't work and not sure why exactly:
using Physics = Unity.Physics;
bool TraceRaySphere
(
float3 spherePos ,
float sphereRadius ,
float3 rayStart ,
float3 rayEnd ,
out Physics.RaycastHit raycastHit
)
{
var ray = new Physics.RaycastInput{
Start = rayStart ,
End = rayEnd ,
Filter = Physics.CollisionFilter.Default
};
var geometry = new Physics.SphereGeometry{
Center = spherePos ,
Radius = sphereRadius
};
var sphere = new Physics.SphereCollider{
Geometry = geometry ,
Filter = Physics.CollisionFilter.Default
};
return sphere.CastRay( ray , out raycastHit );
}
This works, but uses mentioned SphereCollider.Create(geometry) factory method I want to get rid of (if that's possible):
public static bool TraceRaySphere
(
float3 spherePos ,
float sphereRadius ,
float3 rayStart ,
float3 rayEnd ,
out RaycastHit raycastHit
)
{
var ray = new RaycastInput{
Start = rayStart ,
End = rayEnd ,
Filter = CollisionFilter.Default
};
var geometry = new SphereGeometry{
Center = spherePos ,
Radius = sphereRadius
};
var sphereBlobAsset = SphereCollider.Create( geometry );
bool didHit = sphereBlobAsset.Value.CastRay( ray , out raycastHit );
sphereBlobAsset.Dispose();
return didHit;
}

Answer 1

In my project i use following helper method to cast any Colliders (needs unsafe code execution flag because its working with the pointer)
public static unsafe bool ColliderCast(float3 rayFrom, float3 rayTo, quaternion rotation, CollisionWorld collisionWorld, PhysicsCollider collider)
{
ColliderCastInput input = new ColliderCastInput()
{
Collider = (Collider*)collider.Value.GetUnsafePtr(),
Orientation = rotation,
Start = rayFrom,
End = rayTo
};
return collisionWorld.CastCollider(input);
}
And i also have a CollisionGeome
trySingleton class which contains this
//Cache geometries (float3 = size, float3 = center)
private IDictionary<Tuple<float3, float3>, BoxGeometry> boxGeometries;
public BoxGeometry CreateOrGetBoxGeometry(float3 size, float3 center)
{
if(this.boxGeometries == null)
{
this.boxGeometries = new Dictionary<Tuple<float3,float3>, BoxGeometry>();
}
Tuple<float3, float3> key = new Tuple<float3, float3>(size, center);
if(!this.boxGeometries.ContainsKey(key))
{
this.boxGeometries.Add(key, new BoxGeometry { Size = key.Item1, Center = key.Item2, Orientation = quaternion.identity });
}
return this.boxGeometries[key];
}
This allows me to use
BoxCollider.Create
(
CollisionGeomeotrySingleton.Instance.CreateOrGetBoxGeometry(5, 5),
CollisionFilterSingleton.Instance.CollidesWithPlayerFilter
)
You could go now one step further and store the BoxCollider also in the CollisionGeometrySingleton

Answer 2

SphereCollider struct contains few hidden private fields that requires Init(args) method to be called in order to set those up with proper values:
public static bool TraceRaySphere
(
float3 spherePos ,
float sphereRadius ,
float3 rayStart ,
float3 rayEnd ,
out RaycastHit raycastHit
)
{
var ray = new RaycastInput
{
Start = rayStart ,
End = rayEnd ,
Filter = CollisionFilter.Default
};
var geometry = new SphereGeometry
{
Center = spherePos ,
Radius = sphereRadius
};
var sphere = default(SphereCollider);
sphere.Init( geometry , CollisionFilter.Default , Material.Default );
return sphere.CastRay( ray , out raycastHit );
}
However
this method is private (chances are this may change).
To make Init method available you need to modify ...\com.unity.physics#0.5.0-preview.1\Unity.Physics\Collision\Colliders\Physics_SphereCollider.cs source file and make it public.