PhysicalProperties is an object that describes several physical properties of a part: Density, Elasticity and Friction. It is used in the similarly-named
PhysicalProperties also provides weightings properties, ElasticityWeight and FrictionWeight. When two parts interact, the Friction and Elasticity between them are determined in the same way by the following pairwise weighted average function:
Although the formula above refers to the Friction and FrictionWeight of two parts, A and B, the formula is used in the same manner when determining Elasticity. Generally, when the weight of A is much greater than that of B, the actual value will be closer to A. If the weights are similar, then the actual value will be close to the midpoint between their individual values.
PhysicalProperties was released in November 2015. Previously, BasePart had individual Friction and Elasticity properties. This was changed so that all physical properties of a part will replicate as one, among other reasons. Its release was done over the course of three months.