ScanView is a client / server rendering system for viewing complex 3D models, like those produced using laser triangulation scanners, without downloading the models. This lets you interactively examine models that would otherwise be inaccessible due to their large size or due to usage restrictions. In particular, it allows the general public to view the high-resolution 3D models generated during Stanford's Digital Michelangelo Project without obtaining a license.
The client part of ScanView consists of a freely available viewer program and a set of simplified 3D models. Using the viewer, you select one of the simplified models, then position and orient it on your computer screen. Feedback is provided in the form of images rendered from the simplified model. The quality of these image is limited, but it is sufficient for navigation. You can also change the lighting and surface appearance. When you release the mouse, ScanView queries our rendering server (using an HTTP protocol) for an image corresponding to your current view, but rendered from our high-resolution model. This image is sent to your client, overwriting your image of the simplified model. A typical query-response cycle takes 1-2 seconds, but this latency may vary depending on network traffic, the speed of your connection, and the current load on our server.
To prevent "hacking" of the 3D models served by the ScanView system, i.e. reconstruction of a 3D model from the images returned by our rendering server, the server incorporates a number of defenses. Included among these are analyzing the sequence of queries made by a client, encrypting the contents of these queries, perturbing the viewpoint and lighting parameters contained in each query, perturbing the OpenGL lighting model used when rendering the model, warping the rendered image, adding noise to it, and compressing it with quantization before transmission back to the client. These defenses are discussed in our SIGGRAPH 2004 paper (see below).
ScanView currently runs on any Windows-based PC, with or without hardware graphics acceleration. It is currently configured to visualize two (normally inaccessible) models from the Digital Michelangelo Project's Archive of 3D Models (David and St. Matthew), one publically accessible fragment of the Forma Urbis Romae, a giant marble map of ancient Rome, and two models from the unrestricted Stanford 3D Scanning Repository (the bunny and the happy buddha).
The ScanView system was developed by David Koller, Michael Turitzin, and Marc Levoy of the Stanford Computer Graphics Laboratory. See the bottom of this web page for the copyright notice and usage restrictions. The ScanView system is described in a SIGGRAPH 2004 paper by us and Marco Tarini, Giuseppe Croccia, Paolo Cignoni, and Roberto Scopigno. A shortened version of this paper was the cover article in the June 2005 issue of CACM.
After installation, when you run the ScanView client viewer, you should see a 3D shaded rendering of Michelangelo's David. You can rotate and translate the model by dragging using the left and right mouse buttons, respectively, you can zoom by dragging with the left and right buttons pressed at the same time, and you can change the lighting by dragging using the middle mouse button. You can also select different models by clicking on File -> Open model.
Complete instructions for using ScanView and a Frequently Asked Questions (FAQ) page are also available.
In addition, over one thousand models from the Forma Urbis Romae project (mentioned above) are available through our web-browsable relational database of the map. Note: to access these models, you must upgrade to at least version 1.2 of the viewer.
More models may become available shortly, and can be downloaded separately, so check back here soon!
During the period 1995-2007, this software was covered by the Stanford Computer Graphics Laboratory's custom-written General Software License. For downloads beginning on August 23, 2007, this software is covered by a new General Software License, which is based on the BSD license.
In addition to these terms and conditions, which govern the software, users are advised that the 3D models provided with this client viewer, and the images produced by the viewer and downloaded by our rendering server when you release the mouse, are also protected by copyright law. Some of these models and images have usage restrictions. To view the restrictions associated with a particular model, first select the model by clicking on File -> Select model, then click on Help -> About this model.
These usage restrictions are most stringent, and we at the Stanford Computer Graphics Laboratory are most concerned, about the models and images we are providing of the statues of Michelangelo. The Italian authorities who gave us permission to scan these statues are required by Italian law to restrict who may obtain 3D models and images of these statues, and how these models and images may be used. These authorities have given us permission to distribute this client / server rendering system as a way to broaden public access to the statues while still adhering to the law. This is an experiment. Please don't try to hack our client viewer or our rendering server, and don't try to crack our encrypted file format. In general, don't try to extract a 3D model from our system. Similarly, don't violate the per-model usage restrictions (displayable in the viewer, as described above) that apply to images produced by the viewer and the rendering server. Jointly, our good behavior in this matter will encourage other cultural institutions to permit their 3D artifacts to be digitized and made freely available to the public.
graphics-scanview@lists.stanford.edu