Dynamic worlds in miniature

The World in Miniature (WIM) metaphor allows users to interact and travel efficiently in virtual environments. In addition to the first-person perspective offered by typical VR applications, the WIM offers a second dynamic viewpoint through a hand-held miniature copy of the virtual environment. In the original WIM paper the miniature was a scaled down replica of the whole environment, thus limiting the technique to simple models being manipulated at a single level of scale. Several WIM extensions have been proposed where the replica shows only a part of the virtual environment. In this paper we present an improved visualization of WIM that supports arbitrarily-complex, densely-occluded scenes. In particular, we discuss algorithms for selecting the region of the virtual environment which will be covered by the miniature copy and efficient algorithms for handling 3D occlusion from an exocentric viewpoint.Peer ReviewedPostprint (author’s final draft

Octree-based view-dependent triangle meshes

In this paper we present a new technique for view-dependent LOD rendering, where the scene is represented through an octree model from which we can obtain a triangle mesh corresponding to a view-dependent LOD. We present the construction of this octree model and the visualization algorithm that generates on-the-fly a closed and valid triangle mesh for each frame of the visualization. This visualization algorithm is a depth-first traversal algorithm which also allows to re-use triangles from one frame to another

Dynamic worlds in miniature

The World in Miniature (WIM) metaphor allows users to interact and travel efficiently in virtual environments. In addition to the first-person perspective offered by typical VR applications, the WIM offers a second dynamic viewpoint through a hand-held miniature copy of the virtual environment. In the original WIM paper the miniature was a scaled down replica of the whole environment, thus limiting the technique to simple models being manipulated at a single level of scale. Several WIM extensions have been proposed where the replica shows only a part of the virtual environment. In this paper we present an improved visualization of WIM that supports arbitrarily-complex, densely-occluded scenes. In particular, we discuss algorithms for selecting the region of the virtual environment which will be covered by the miniature copy and efficient algorithms for handling 3D occlusion from an exocentric viewpoint.Peer Reviewe

Dynamic worlds in miniature

The World in Miniature (WIM) metaphor allows users to interact and travel efficiently in virtual environments. In addition to the first-person perspective offered by typical VR applications, the WIM offers a second dynamic viewpoint through a hand-held miniature copy of the virtual environment. In the original WIM paper the miniature was a scaled down replica of the whole environment, thus limiting the technique to simple models being manipulated at a single level of scale. Several WIM extensions have been proposed where the replica shows only a part of the virtual environment. In this paper we present an improved visualization of WIM that supports arbitrarily-complex, densely-occluded scenes. In particular, we discuss algorithms for selecting the region of the virtual environment which will be covered by the miniature copy and efficient algorithms for handling 3D occlusion from an exocentric viewpoint.Peer Reviewe

World-in-miniature interaction for complex virtual environments

Object occlusion is a major handicap for efficient interaction with 3D virtual environments. The well-known World in Miniature (WIM) metaphor partially solves this problem by providing an additional dynamic view point through a hand-held miniature copy of the scene. However, letting the miniature show a replica of the whole scene makes WIM metaphor suitable for only relatively simple scenes due to occlusion and level of scale issues. In this paper, the authors propose several algorithms to extend the idea behind the WIM to arbitrarily complex scenes. The main idea is to automatically decompose indoor scenes into a collection of cells that define potential extents of the miniature replica. This cell decomposition works well for general indoor scenes and allows for simple and efficient algorithms for preserving the visibility of potential targets inside the cell. The authors also discuss how to support interaction at multiple levels of scale by allowing the user to select the WIM size according to the accurazy required for accomplishing the task

Complexity and occlusion management for the World-in-Miniature Metaphor

he World in Miniature (WIM) metaphor allows users to interact and travel efficiently in virtual environments. In addition to the first-person perspective offered by typical VR applications, the WIM offers a second dynamic viewpoint through a hand-held miniature copy of the environment. In the original WIM paper the miniature was a scaled down replica of the whole scene, thus limiting its application to simple models being manipulated at a single level of scale. Several WIM extensions have been proposed where the replica shows only a part of the environment. In this paper we present a new approach to handle complexity and occlusion in the WIM. We discuss algorithms for selecting the region of the scene which will be covered by the miniature copy and for handling occlusion from an exocentric viewpoint. We also present the results of a user-study showing that our technique can greatly improve user performance on spatial tasks in densely-occluded scenes.Peer Reviewe

Multi-scale manipulation in indoor scenes with the World in Miniature Metaphor

The World in Miniature Metaphor (WIM) allows users to select, manipulate and navigate efficiently in virtual environments. In addition to the first-person perspective offered by typical VR applications, the WIM offers a second dynamic viewpoint through a hand-held miniature copy of the environment. In this paper we explore different strategies to allow the user to interact with the miniature replica at multiple levels of scale. Unlike competing approaches, we support complex indoor environments by explicitly handling occlusion. We discuss algorithms for selecting the part of the scene to be included in the replica, and for providing a clear view of the region of interest. Key elements of our approach include an algorithm to recompute the active region from a subdivision of the scene into cells, and a view-dependent algorithm to cull-away occluding geometry through a small set of slicing planes roughly oriented along the main occluding surfaces. We present the results of a user-study showing that our technique clearly outperforms competing approaches on spatial tasks performed in densely-occluded scenes.Postprint (published version

World-in-miniature interaction for complex virtual environments

Object occlusion is a major handicap for efficient interaction with 3D virtual environments. The well-known World in Miniature (WIM) metaphor partially solves this problem by providing an additional dynamic view point through a hand-held miniature copy of the scene. However, letting the miniature show a replica of the whole scene makes WIM metaphor suitable for only relatively simple scenes due to occlusion and level of scale issues. In this paper, the authors propose several algorithms to extend the idea behind the WIM to arbitrarily complex scenes. The main idea is to automatically decompose indoor scenes into a collection of cells that define potential extents of the miniature replica. This cell decomposition works well for general indoor scenes and allows for simple and efficient algorithms for preserving the visibility of potential targets inside the cell. The authors also discuss how to support interaction at multiple levels of scale by allowing the user to select the WIM size according to the accurazy required for accomplishing the task

Multi-scale manipulation in indoor scenes with the World in Miniature Metaphor

The World in Miniature Metaphor (WIM) allows users to select, manipulate and navigate efficiently in virtual environments. In addition to the first-person perspective offered by typical VR applications, the WIM offers a second dynamic viewpoint through a hand-held miniature copy of the environment. In this paper we explore different strategies to allow the user to interact with the miniature replica at multiple levels of scale. Unlike competing approaches, we support complex indoor environments by explicitly handling occlusion. We discuss algorithms for selecting the part of the scene to be included in the replica, and for providing a clear view of the region of interest. Key elements of our approach include an algorithm to recompute the active region from a subdivision of the scene into cells, and a view-dependent algorithm to cull-away occluding geometry through a small set of slicing planes roughly oriented along the main occluding surfaces. We present the results of a user-study showing that our technique clearly outperforms competing approaches on spatial tasks performed in densely-occluded scenes

Complexity and occlusion management for the World-in-Miniature Metaphor

he World in Miniature (WIM) metaphor allows users to interact and travel efficiently in virtual environments. In addition to the first-person perspective offered by typical VR applications, the WIM offers a second dynamic viewpoint through a hand-held miniature copy of the environment. In the original WIM paper the miniature was a scaled down replica of the whole scene, thus limiting its application to simple models being manipulated at a single level of scale. Several WIM extensions have been proposed where the replica shows only a part of the environment. In this paper we present a new approach to handle complexity and occlusion in the WIM. We discuss algorithms for selecting the region of the scene which will be covered by the miniature copy and for handling occlusion from an exocentric viewpoint. We also present the results of a user-study showing that our technique can greatly improve user performance on spatial tasks in densely-occluded scenes.Peer Reviewe