摘要 |
A limitation of modeling three-dimensional objects in a virtual world occurs when a user moves within the world and still wishes a certain target object to remain visible, instead of being occluded by other surfaces in front of the object along the direction the user is viewing the target object. Therefore, in accordance with the principles of the invention, a target object which is to remain visible, regardless of the user's view point, is duplicated and modeled as being located a close distance to the user, but scaled accordingly to make the cloned object appear to be farther away from the viewpoint of the user and co-located with and of the same size and orientation as the target object. In this manner, as the user moves within the world, surfaces located in front of the target object do not occlude the cloned object from the user's view, thus appearing to give that same property to the target object.
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