  Three-dimensional hydrodynamic numerical simulations have demonstrated that
the structure of a protoplanetary disc may be strongly affected by a planet
orbiting in a plane that is misaligned to the disc. When the planet is able to
open a gap, the disc is separated into an inner, precessing disc and an outer
disc with a warp. In this work, we compute infrared scattered light images to
investigate the observational consequences of such an arrangement. We find that
an inner disc misaligned by a less than a degree to the outer disc is indeed
able to cast a shadow at larger radii. In our simulations a planet of around 6
Jupiter masses inclined by around 2 degrees is enough to warp the disc and cast
a shadow with a depth of more than 10% of the average flux at that radius. We
also demonstrate that warp in the outer disc can cause a variation in the
azimuthal brightness profile at large radii. Importantly, this latter effect is
a function of the distance from the star and is most prominent in the outer
disc. We apply our model to the TW Hya system, where a misaligned, precessing
inner disc has been invoked to explain an recently observed shadow in the outer
disc. Consideration of the observational constraints suggest that an inner disc
precessing due to a misaligned planet is an unlikely explanation for the
features found in TW Hya.
