Blog Archive: 2009

Generating 3D models from webcams

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One highly inconvenient thing about working with virtual worlds or 3D content in general is: where do your 3D models come from (especially if you’re on a budget)? A talented but (inevitably) overworked 3D artist? An online catalog of variable quality and cost? Messing around yourself with tools like SketchUp or Blender? What if you want something very specific, very quickly? The MIR (Mixed and Immersive Realities) team here at FXPAL is very interested in these questions and has done some work in this area. Others are working on it too: here’s an elegant demo from Qi Pan at the University of Cambridge, showing the construction of a model with textures from a webcam image:

Marking Up a World: Physical Markup for Virtual Content Creation

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FXPAL’s Pantheia system enables users to create virtual models by ‘marking up’ a physical scene with pre-printed visual markers and then taking pictures. The meanings associated with the markers come from a markup language that enables users to specify geometric, appearance, or interactive aspects of the model that are then used by the system to construct the model.  Our “Marking up the World” video appeared at ACM Multimedia this week. In the video you can see how our system works, our viewer features, and a selection of the spaces and objects we have used the system to reconstruct.

Thanks much to Qiong Liu for presenting it, and to John Doherty for putting it together from our clips and for narrating it. The geometric reconstruction work I spoke about last week as part of the Bay Area Mathematical Adventures series was inspired by the issues we discovered while building the system. For more details on our work, see the paper we presented at CGVR ’09 Interactive Models from Images of a Static Scene.

When Worlds Collide (pt. 2): mix-n-mesh

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Or, when worlds collage…

In yesterday’s post I promised to discuss my favorite feature in the beta version of the 3D web browser Exit Reality. This was the discovery: as a way to create rich 3D worlds quickly, you can stack worlds and models — and their accompanying scripts and animations — inside of each other, all inside one browser window. The Exit Reality 3D search provides a rich source of 3D objects and worlds; you simply drag-and-drop them from the search results into your open world-window.

The collage effect is less of a mess than you might expect, despite differing scales and environment settings. Or OK, it’s a mess, but an interesting mess.

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What is this thing called Search?

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In a recent blog post, Vegard Sandvold proposed a taxonomy of search systems based on two dimensions — algorithmic vs. user-powered and information accessibility. The first dimension represents a tradeoff between systems and people in terms of who does the information seeking, and the second one measures the ease of finding information in some search space. His blog post was intended to solicit discussion, and, in that spirit, here is my take on his ideas.

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Models of interaction, part 1

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Recently, I’ve been involved in a lot of discussions about exploratory search on this blog and in comments on The Noisy Channel. One way to look at exploratory search (and there are many others!) is to separate issues of interaction from issues of retrieval. The two are complementary: for example, recently Daniel Tunkelang posted about using sets rather than ranked lists as a way of representing search results. This has implications on one hand for how the retrieval engine identifies promising documents, and on the other for how results are to be communicated to the user, and how the user should interact with them.

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