Architectural endoscope camera rig publications

We present a method to acquire the reflectance field of a human face and use these measurements to render the face under arbitrary changes in lighting and viewpoint. We first acquire images of the face from a small set of viewpoints under a dense sampling of incident illumination directions using a light stage. We then construct a reflectance function image for each observed image pixel from its values over the space of illumination directions. From the reflectance functions, we can directly generate images of the face from the original viewpoints in any form of sampled or computed illumination. To change the viewpoint, we use a model of skin reflectance to estimate the appearance of the reflectance functions for novel viewpoints. We demonstrate the technique with synthetic renderings of a person’s face under novel illumination and viewpoints.

We describe a process for compositing a live performance of an ac- tor into a virtual set wherein the actor is consistently illuminated by the virtual environment. The Light Stage used in this work is a two-meter sphere of inward-pointing RGB light emitting diodes fo- cused on the actor, where each light can be set to an arbitrary color and intensity to replicate a real-world or virtual lighting environ- ment. We implement a digital two-camera infrared matting system to composite the actor into the background plate of the environ- ment without affecting the visible-spectrum illumination on the ac- tor. The color reponse of the system is calibrated to produce correct color renditions of the actor as illuminated by the environment. We demonstrate moving-camera composites of actors into real-world environments and virtual sets such that the actor is properly illumi- nated by the environment into which they are composited.

The hypothesis that way-finding performance depends on the visual characte- ristics of the street-scape was investigated by an experiment using a user-controlled space-sequence simulator which was designed to allow a subject to move through a model space and visually experience a travel sequence. Three scale models (1:150) of an identical maze pattern each with a different street- scape were used in the simulator. The three types of street-scapes were: (1) no characteristics, with monotonous surfaces, (2) each corner distinguished with a different building, and (3) streets furnished with trees, columns or fences. Each subject was first asked to memorize the route by viewing a pre- determined continuous sequence of model streets, as shown on the screen, then asked to take the instructed route. This procedure was repeated until a subject successfully reached the end of the route. Subjects were allowed to try up to five times. After the experiment, the subjects were asked to draw a cog- nitive map of the route. Three male and three female subjects were tested in each of three street types. An analysis of the results generally supported the hypothesis that a route in streets with significant visual characteristics was easier to memorize, although there was a large difference in performance between subjects. With an analysis of the cognitive maps drawn by the sub- jects, it was noted that subjects seemed to rely more on incoming visual infor- mation on the changing scene than on structured knowledge of the route, as is emphasized in conventional theory of way-finding.

To enable students to evaluate the impact of light on the scale models of their architectural projects, two physical simulation systems have been built: a mirror box and a sun and sky simulator. Both devices integrate LED-based light sources. We have integrated several models for the computation of the sky image: luminance models and colour appearance models. The integration of the recent and evolving LED technologies explains how our simulators are innovative.