A system for simulating tool paths based on thermal/structural simulations of a part being additively produced via a three-dimensional printer comprising: at least one processor configured to carry out a first simulation of the part being additively produced according to a first set of tool paths (110, 120) that correspond to instructions usable to drive a three-dimensional printer to move a laser to additively produce the part, wherein the at least one processor is configured to: receive computer-aided design data defining a three-dimensional model of the part; determine, based on the three-dimensional model, a mesh of the part that partitions the space of the part into a plurality of three-dimensional elements; determine, based on the first set of tool paths, an order of the elements of the mesh to deposit for additively producing the part; simulate an incremental deposit of each of the mesh's elements (122, 134) in the order that the elements are determined to be deposited, said simulation step comprising: determine, for each incremental deposit of an additional element (122, 134), thermal characteristics and structural deformation characteristics of the deposited elements (122, 134), wherein the determined thermal characteristics include data that specifies temperature changes of the deposited elements (122, 134) and the determined structural deformation characteristics include data that specifies structural changes of the deposited elements (122, 134) determined based at least in part on the data that specifies temperature changes of the deposited elements, and modify, for at least one such additional element (122, 134), the mesh to change a volume of the additional element (122, 134) so as to account for a volume change of the additional element (122, 134) resulting from structural deformation of at least one adjacent deposited element, wherein the volume change is determined from the previously determined structural deformation characteristics. receive computer-aided design data defining a three-dimensional model of the part; determine, based on the three-dimensional model, a mesh of the part that partitions the space of the part into a plurality of three-dimensional elements; determine, based on the first set of tool paths, an order of the elements of the mesh to deposit for additively producing the part; simulate an incremental deposit of each of the mesh's elements (122, 134) in the order that the elements are determined to be deposited, said simulation step comprising: determine, for each incremental deposit of an additional element (122, 134), thermal characteristics and structural deformation characteristics of the deposited elements (122, 134), wherein the determined thermal characteristics include data that specifies temperature changes of the deposited elements (122, 134) and the determined structural deformation characteristics include data that specifies structural changes of the deposited elements (122, 134) determined based at least in part on the data that specifies temperature changes of the deposited elements, and modify, for at least one such additional element (122, 134), the mesh to change a volume of the additional element (122, 134) so as to account for a volume change of the additional element (122, 134) resulting from structural deformation of at least one adjacent deposited element, wherein the volume change is determined from the previously determined structural deformation characteristics. determine, for each incremental deposit of an additional element (122, 134), thermal characteristics and structural deformation characteristics of the deposited elements (122, 134), wherein the determined thermal characteristics include data that specifies temperature changes of the deposited elements (122, 134) and the determined structural deformation characteristics include data that specifies structural changes of the deposited elements (122, 134) determined based at least in part on the data that specifies temperature changes of the deposited elements, and modify, for at least one such additional element (122, 134), the mesh to change a volume of the additional element (122, 134) so as to account for a volume change of the additional element (122, 134) resulting from structural deformation of at least one adjacent deposited element, wherein the volume change is determined from the previously determined structural deformation characteristics.