Abstract: Methods, systems, and apparatus, including medium-encoded computer program products, for creating one or more gradients of different materials for a three dimensional (3D) surface model include, in one aspect, a system including: an additive manufacturing machine designed to use different materials in combination with each other when manufacturing objects; and means for creating a discretized gradient for a 3D surface model of an object, to be manufactured using the additive manufacturing machine, by inserting one or more 3D surfaces into the 3D surface model at specified locations, thereby creating a non-manifold version of the 3D surface model having multiple discrete volumetric regions, and assigning a material specification to each of the discrete volumetric regions, each of the material specifications being either a single one of the different materials or a specified combination of the different materials, which are usable by the additive manufacturing machine to manufacture the object.

Abstract: Methods, systems, and apparatus, including medium-encoded computer program products, for creating one or more gradients of different materials for a three dimensional (3D) surface model include, in one aspect, a system including: an additive manufacturing machine designed to use different materials in combination with each other when manufacturing objects; and means for creating a discretized gradient for a 3D surface model of an object, to be manufactured using the additive manufacturing machine, by inserting one or more 3D surfaces into the 3D surface model at specified locations, thereby creating a non-manifold version of the 3D surface model having multiple discrete volumetric regions, and assigning a material specification to each of the discrete volumetric regions, each of the material specifications being either a single one of the different materials or a specified combination of the different materials, which are usable by the additive manufacturing machine to manufacture the object.

Abstract: A method of collecting, preserving and repositioning snow on a ski slope whereby the slope may be placed in condition for skiing in the fall prior to the time of sufficient fall of natural snow or the arrival of freezing conditions necessary for the production of man-made snow.

Abstract: A tree slasher in which the entire trunk of a tree may be simultaneously cut into a plurality of selected lengths to meet subsequent processing requirements. The slasher, while large, is mobile and may, if desired, be taken to the vicinity of the tree-cutting areas thereby to minimize the distances the tree trunks must be hauled prior to cutting.