We investigate pointing in true 3D environments where the target size varies in three spatial dimensions. We also study the effect of the user's physical movement angle on pointing performance. Results show that target size dimension along the primary axis of movement has a greater impact on performance than the other two dimensions. Movement angle also significantly affects performance, and changes the relative impact of the three target dimensions. Building upon recent results in the modeling of bivariate pointing, we propose and validate a new model that describes pointing at trivariate targets. This model also accounts for movement angle, and outperforms previously published models.