Viewer (LSV), is an efficient hybrid global rendering method which combines forward ray tracing with radiosity and shadow volumes rendering. This algorithm is described in [9]. The engine creates rendered images of daylit scenes and calculates the illuminance on areabased patch sensors. Early validation results indicated that rendered images by LSV displayed a pixel difference of less than 10% from Radiance for a variety of scenes, camera positions, and daylighting conditions [9]. Analysis comparing data collected from area-based patch sensors with point sensors in Radiance indicated similar values with an overall highest difference of 28% [6]. Further improvement and validation of this engine is currently underway.