Radiance is a suite of programs for the analysis and visualization of
lighting in design. However, the architects rarely use them during the
design process because the renderings often take minutes to hours to
produce and it needs a lot of knowledge to produce quick images. In
this talk, we present an interactive rendering system for
architectural design using a hybrid method of shadow volumes for
direct illumination and radiosity for indirect illumination to achieve
interactive rendering rates. Our system also supports the rendering of
Complex Fenestration System based on 4D Bidirectional Transmission
Distribution Function (BTDF) data. Our system is appropriate for use
in schematic design: an early stage of the architectural design
process where scale, appearance, and adjacencies of an evolving design
are explored. We compare the rendering speed and accuracy with
Radiance to demonstrate the validity of our system.