Abstract: At least one agent distributor may be to selectively deliver coalescing agent onto portions of a layer of build material at a first density and at a second density lower than the first density. A controller may be to control the at least one agent distributor to selectively deliver the coalescing agent at the first and second densities onto respective first and second portions of the layer in respective first and second patterns derived from data representing the three-dimensional object to be generated, so that when energy is applied to the layer the build material may coalesce and solidify to form a slice of the three-dimensional object in accordance with the first pattern. The second portion may be in proximity to a boundary of the first portion. Presence of the coalescing agent in the second portion may be to prevent at least some heat from flowing away from the first portion when the energy is applied.

Abstract: Agent calibration can, in an example implementation, include generating a calibration based on a quantity of energy absorbed by a build material treated with different quantities of an agent and converting a portion of a three-dimensional object model to a quantity of agent based on the calibration.

Abstract: Adjustment of a halftoning threshold can, in an example implementation, include assigning a relative energy value, relative to a reference energy value, to a location of a build area and adjusting a halftoning threshold based on the relative energy value.

Abstract: At least one agent distributor may be to selectively deliver coalescing agent onto portions of a layer of build material at a first density and at a second density lower than the first density. A controller may be to control the at least one agent distributor to selectively deliver the coalescing agent at the first and second densities onto respective first and second portions of the layer in respective first and second patterns derived from data representing the three-dimensional object to be generated, so that when energy is applied to the layer the build material may coalesce and solidify to form a slice of the three-dimensional object in accordance with the first pattern. The second portion may be in proximity to a boundary of the first portion. Presence of the coalescing agent in the second portion may be to prevent at least some heat from flowing away from the first portion when the energy is applied.

Abstract: At least one agent distributor may be to selectively deliver coalescing agent onto portions of a layer of build material at a first density and at a second density lower than the first density. A controller may be to control the at least one agent distributor to selectively deliver the coalescing agent at the first and second densities onto respective first and second portions of the layer in respective first and second patterns derived from data representing the three-dimensional object to be generated, so that when energy is applied to the layer the build material may coalesce and solidify to form a slice of the three-dimensional object in accordance with the first pattern. The second portion may be in proximity to a boundary of the first portion. Presence of the coalescing agent in the second portion may be to prevent at least some heat from flowing away from the first portion when the energy is applied.

Abstract: Adjustment of a halftoning threshold can, in an example implementation, include assigning a relative energy value, relative to a reference energy value, to a location of a build area and adjusting a halftoning threshold based on the relative energy value.

Abstract: At least one agent distributor may be to selectively deliver coalescing agent onto portions of a layer of build material at a first density and at a second density lower than the first density. A controller may be to control the at least one agent distributor to selectively deliver the coalescing agent at the first and second densities onto respective first and second portions of the layer in respective first and second patterns derived from data representing the three-dimensional object to be generated, so that when energy is applied to the layer the build material may coalesce and solidify to form a slice of the three-dimensional object in accordance with the first pattern. The second portion may be in proximity to a boundary of the first portion. Presence of the coalescing agent in the second portion may be to prevent at least some heat from flowing away from the first portion when the energy is applied.

Abstract: Agent calibration can, in an example implementation, include generating a calibration based on a quantity of energy absorbed by a build material treated with different quantities of an agent and converting a portion of a three-dimensional object model to a quantity of agent based on the calibration.