A method for determining and optimizing manufacturing of an object by additive manufacturing. One or more computers access a three-dimensional digital model of the object and automatically generate a selected number of versions of supports for manufacture of the object. An image of the generated supports is displayed along with the object for visual perception by a user. The user visually observes the displayed versions of supports and object and uses the images to evaluate whether manufacturing the object by additive manufacturing is viable and whether the additive manufacturing supports are optimized. When viable, the object may be built by additive manufacturing using the optimized additive manufacturing supports to support the object.