void DrawDispCollPlane( CBaseTrace *pTrace )
{
  float flLength = 30.0f;

  // Create a basis, based on the impact normal.
  int nMajorAxis = 0;
  Vector vecBasisU, vecBasisV, vecNormal;
  vecNormal = pTrace->plane.normal;
  float flAxisValue = vecNormal[0];
  if ( fabs( vecNormal[1] ) > fabs( flAxisValue ) ) { nMajorAxis = 1; flAxisValue = vecNormal[1]; }
  if ( fabs( vecNormal[2] ) > fabs( flAxisValue ) ) { nMajorAxis = 2; }
  if ( ( nMajorAxis == 1 ) || ( nMajorAxis == 2 ) )
  {
   vecBasisU.Init( 1.0f, 0.0f, 0.0f );
  }
  else
  {
   vecBasisU.Init( 0.0f, 1.0f, 0.0f );
  }

  vecBasisV = vecNormal.Cross( vecBasisU );
  VectorNormalize( vecBasisV );

  vecBasisU = vecBasisV.Cross( vecNormal );
  VectorNormalize( vecBasisU );

  // Create the impact point.  Push off the surface a bit.
  Vector vecImpactPoint = pTrace->startpos + pTrace->fraction * ( pTrace->endpos - pTrace->startpos );
  vecImpactPoint += vecNormal;

  // Generate a quad to represent the plane.
  Vector vecPlanePoints[4];
  vecPlanePoints[0] = vecImpactPoint + ( vecBasisU * -flLength ) + ( vecBasisV * -flLength );
  vecPlanePoints[1] = vecImpactPoint + ( vecBasisU * -flLength ) + ( vecBasisV * flLength );
  vecPlanePoints[2] = vecImpactPoint + ( vecBasisU * flLength ) + ( vecBasisV * flLength );
  vecPlanePoints[3] = vecImpactPoint + ( vecBasisU * flLength ) + ( vecBasisV * -flLength );

#if 0
  // Test facing.
  Vector vecEdges[2];
  vecEdges[0] = vecPlanePoints[1] - vecPlanePoints[0];
  vecEdges[1] = vecPlanePoints[2] - vecPlanePoints[0];
  Vector vecCross = vecEdges[0].Cross( vecEdges[1] );
  if ( vecCross.Dot( vecNormal ) < 0.0f )
  {
   // Reverse winding.
  }
#endif

  // Draw the plane.
  NDebugOverlay::Triangle( vecPlanePoints[0], vecPlanePoints[1], vecPlanePoints[2], 125, 125, 125, 125, false, 5.0f );
  NDebugOverlay::Triangle( vecPlanePoints[0], vecPlanePoints[2], vecPlanePoints[3], 125, 125, 125, 125, false, 5.0f );

  NDebugOverlay::Line( vecPlanePoints[0], vecPlanePoints[1], 255, 255, 255, false, 5.0f );
  NDebugOverlay::Line( vecPlanePoints[1], vecPlanePoints[2], 255, 255, 255, false, 5.0f );
  NDebugOverlay::Line( vecPlanePoints[2], vecPlanePoints[3], 255, 255, 255, false, 5.0f );
  NDebugOverlay::Line( vecPlanePoints[3], vecPlanePoints[0], 255, 255, 255, false, 5.0f );

  // Draw the normal.
  NDebugOverlay::Line( vecImpactPoint, vecImpactPoint + ( vecNormal * flLength ), 255, 0, 0, false, 5.0f );