There is an extensive history of simulations of liquid crystals using simple computational models (see ref 33 for a review), which have been used to provide a basic understanding of the behaviour of these anisotropic molecules. A smaller subset of these studies have examined the interplay of repulsive and attractive interactions in controlling the interfacial orientation. At a free interface (such as that with a vapour phase), the orientation of anisotropic particles has been studied at various levels, ranging from mean field theories, to particle-based molecular dynamics (MD), and Monte-Carlo (MC) simulations. It has been found that switching between the face-on and side-on orientation at this interface can be achieved by tuning the anisotropy of the attractive interactions. In the absence of attractive interactions, the long axis of an anisotropic molecule has been predicted to align perpendicular to the interface due to excluded-volume entropic effects. MD simulations of the Gay-Berne (GB) fluid have indicated a dependence of the orientation at the vapour interface of nematic fluids on the ratio of the shape anisotropy to the interaction anisotropy of the particles. Fluids that are isotropic in the bulk have also been shown to display preferential alignment at a vapour interface. In contrast, at the solid interface, free volume is maximised in the face-on orientation, for which the long molecular axis is parallel to the interface. Density functional theory calculations of hard platelets, and theoretical calculations of hard spherocylinders and spheroplatelets at hard impenetrable walls show a preference for alignment with the short axis of the molecule perpendicular to the wall due to entropic effects and minimisation of the surface tension. The inclusion of attractive interactions between fluid particles has been predicted to introduce a temperature dependence to interface orientation, with systems at high temperatures showing the same alignment as the purely repulsive systems due to the dominance of entropy, and a transition to the opposite alignment at lower temperatures as energetic effects become more significant. Many computational studies of specific systems have shown similar dependences on temperature and interaction anisotropy. In general, the orientation at the solid interface depends on both the strength and anisotropy of the fluid-substrate interactions, and the strength of the fluid-fluid interactions. A number of experimental studies report control of orientation at this interface for specific small molecules, and the strength of the interactions with the substrate has been shown to directly influence the orientation, again for a specific set of interaction parameters. An interesting illustration of the contrasting behaviour of hard particles at solid and vapour interfaces is the case of a penetrable wall, from which a particle's centre-of-mass is repelled but which the rest of the molecule can penetrate to varying degrees. As the wall interacts isotropically with the centre-of-mass of the anisotropic particle, a highly penetrable wall is qualitatively similar to a free interface, whereas a impenetrable wall represents a solid interface. MC and density functional theory calculations of these interfaces show a transition between face-on alignment at an impenetrable surface and side-on alignment at a fully penetrable wall, consistent with previous theoretical predictions at solid and vapour interfaces, respectively, due to excluded-volume entropic effects. Although a number of general rules that appear to be relatively predictive for determining the orientation of anisotropic particles at both solid and vapour interfaces exist, and many specific examples of orientation control can be found in the literature, a more detailed understanding of how molecular shape and interactions control the orientation in general, and the ability to predict orientation based on combined energetic and entropic contributions using a simple analytical expression, is lacking. In this work, we investigate a series of disk-shaped OSC-like systems using equilibrium coarse-grained MD simulations of GB particles between solid and vapour-like interfaces. These simulations allow for systematic tuning of the strength of the interactions, shape of the anisotropic molecule, and its interactions with the substrate, to gain an understanding of how the interplay of these features influences the orientation at both the solid and vapour interfaces. The use of GB particles, which have a simple ellipsoidal shape, means that these results should be generally applicable to a wide range of molecules, whether OSCs or not, that share similar shapes and interactions, rather than specific to a single type or class of chemical structure.