We present a general, proxy-based approach to volume haptics founded upon the notion of ?haptic primitives?. Haptic modes each representing a different aspect of volumetric data, are created by defining sets of haptic primitives which reflect the local properties of the data. The proxy position for every time-frame in the haptic loop is found by balancing the force feedback in the haptic instrument with the force from the haptic primitives involved. The presented general framework allows for rapid development of haptic feedback modes for volumetric data. The approach also allows, in contrast to previous work on proxy-based volume haptics, combination of non-orthogonal constraints and thus allows free combination of various modes in haptic exploration of multivariate data. We demonstrate the effectiveness of our approach through the implementation of five different haptic modes.