The Mission Editor has something that does this, but it requires an "Editor" object and is client-side only:
//-----------------------------------------------------------------------------
// Torque Game Engine
// Copyright (C) GarageGames.com, Inc.
//-----------------------------------------------------------------------------
//------------------------------------------------------------------------------
// Console onEditorRender functions:
//------------------------------------------------------------------------------
// Functions:
// - renderSphere([pos], [radius], <sphereLevel>);
// - renderCircle([pos], [normal], [radius], <segments>);
// - renderTriangle([pnt], [pnt], [pnt]);
// - renderLine([start], [end], <thickness>);
//
// Variables:
// - consoleFrameColor - line prims are rendered with this
// - consoleFillColor
// - consoleSphereLevel - level of polyhedron subdivision
// - consoleCircleSegments
// - consoleLineWidth
//------------------------------------------------------------------------------
function SpawnSphere::onEditorRender(%this, %editor, %selected, %expanded)
{
if(%selected $= "true")
{
%editor.consoleFrameColor = "255 0 0";
%editor.consoleFillColor = "0 0 0 0";
%editor.renderSphere(%this.getWorldBoxCenter(), %this.radius, 1);
}
}