/// The RenderLightGizmo function will be called if the light is not selected.
/// The gizmo is drawn when picking.

@DrawGizmo (GizmoType.NotSelected | GizmoType.Pickable)
static function RenderLightGizmo (light : Light, gizmoType : GizmoType) {
var position = light.transform.position;
// Draw the light icon
// (A bit above the one drawn by the builtin light gizmo renderer)
Gizmos.DrawIcon (position + Vector3.up, "Light Gizmo.tiff");

// Are we selected? Draw a solid sphere surrounding the light
if ((gizmoType & GizmoType.SelectedOrChild) != 0) {
// Indicate that this is the active object by using a brighter color.
if ((gizmoType & GizmoType.Active) != 0)
Gizmos.color = Color.red;
else
Gizmos.color = Color.red * 0.5;
Gizmos.DrawSphere (position, light.range);
}
}

/*
// Draw the gizmo if it is selected or a child of the selection.
// This is the most common way to render a gizmo
@DrawGizmo (GizmoType.SelectedOrChild)

// Draw the gizmo only if it is the active object.
@DrawGizmo (GizmoType.Active)]
*/

/// C# example
using UnityEditor;
using UnityEngine;

class GizmoTest {
/// The RenderLightGizmo function will be called if the light is not selected.
/// The gizmo is drawn when picking.
[DrawGizmo (GizmoType.NotSelected | GizmoType.Pickable)]
static void RenderLightGizmo (Light light, GizmoType gizmoType) {
Vector3 position = light.transform.position;
// Draw the light icon
// (A bit above the one drawn by the builtin light gizmo renderer)
Gizmos.DrawIcon (position + Vector3.up, "Light Gizmo.tiff");

// Are we selected? Draw a solid sphere surrounding the light
if ((gizmoType & GizmoType.SelectedOrChild) != 0) {
// Indicate that this is the active object by using a brighter color.
if ((gizmoType & GizmoType.Active) != 0)
Gizmos.color = Color.red;
else
Gizmos.color = Color.red * 0.5F;
Gizmos.DrawSphere (position, light.range);
}
}
}
/*
// Draw the gizmo if it is selected or a child of the selection.
// This is the most common way to render a gizmo
[DrawGizmo (GizmoType.SelectedOrChild)]

// Draw the gizmo only if it is the active object.
[DrawGizmo (GizmoType.Active)]
*/