The discrete gradient method is proposed as a novel numerical tool to perform solid mechanics analysis directly on point-cloud models without converting the models into a finite element mesh. This method does not introduce continuous approximation of the primary unknown field variables; instead, it computes the gradients of the field variables at a node using discrete differentials involving a set of neighboring nodes. Therefore, the formulation renders a completely discrete computation that can conduct mechanical analysis on point-cloud representations of patient- specific organs without resorting to finite element method.