string result = "";

var cam = UnityEngine.Camera.main;
var shader = UnityEngine.Shader.Find("Sprites/Default");

if (cam == null || shader == null)
{
    result = "ERROR: Camera or shader missing";
}
else
{
    var old = UnityEngine.GameObject.Find("GreenSphere_Test");
    if (old != null)
        UnityEngine.Object.Destroy(old);

    var sphere = UnityEngine.GameObject.CreatePrimitive(
        UnityEngine.PrimitiveType.Sphere
    );

    sphere.name = "GreenSphere_Test";
    sphere.transform.position =
        cam.transform.position + cam.transform.forward * 3f;
    
    // 必要に応じて大きさを調整してください（例: 3x3x3）
    sphere.transform.localScale = new UnityEngine.Vector3(100f, 100f, 100f);

    var mat = new UnityEngine.Material(shader);
    mat.color = new UnityEngine.Color(0f, 1f, 0f, 1f);

    var rend = sphere.GetComponent<UnityEngine.Renderer>();
    rend.material = mat;

    var col = sphere.GetComponent<UnityEngine.Collider>();
    if (col != null)
        UnityEngine.Object.Destroy(col);

    result = "SUCCESS: Green sphere created";
}

result;