Fragment Shadow (2020)

Credits
– Shunichi Kasahara (Sony CSL)
– Satoru Higa (BACKSPACE Productions Inc. )

Fragment Shadow is an interactive art of real physical shadows cast by audiences in precisely calibrated projection space.

Fragment Shadow system creates a unique projection space with a large screen surface from multiple projectors by comprehensive spatial geometry and color calibration process. When human bodies or objects enter the projection space, the occlusion of one projector reveals images from other projectors on the screen surface.

By leveraging this simple physical phenomenon, shadows are no longer just usual black visual objects. Fragment Shadow enables to generate various visual expression in the optical shadow such as fragmented, transformed, textured and even immersed in the graphics. We achieve this physical transformation of the projected body expression by computational control of lights that create cast body shadows.

Your real shadow is restructured into novel visuals unexpectedly, yet with infinite resolution and zero latency since the shadow is a physical phenomenon. This induces overwhelming reality and we still recognize transformed shadows as “self” and attribute those transformations to ourselves.

This is an interactive system that allows us to interact with transformed self by heterogenization of our shadow, the simplest self-projecting entity.

Support received from
– Ryo Kanda (Kezzardrix)
– Akiko Saito
– Motoi Shimizu
– Ito Yuya
– Juri Oda
– Yoshiko Dokyu
– Kazuma Takada
– Shotaro Hirata
– Akihiro Komori

This is the updated version of this project : https://shunichikasahara.com/portfolio/fragment-shadow/

Technical description

Fragment Shadow system manipulates the physical light to design casted shadows.

Fragment Shadow software systems consist of four technical calibration pipeline: Geometry Calibration, Color Calibration, Uniformity Calibration, and Frame synchronization.

Each projector outputs light from different directions and the casted shadows will appear in different positions on the screen. The geometry calibration computes the spatial coordination between a screen and multiple projectors then it enables consistent visual projection from multiple projectors.

The color system in Fragment Shadow enables the image synthesis pipeline in XYZ color space as a physical color representation by the bi-directional conversion of RGB and XYZ color space. By measuring several standard color outputs from each projector, the system estimates the bi-directional conversion function between digital color representation and physical color output. In addition, the system compensates for the un-uniformity for each projector by computing the illuminance attenuation on the screen.

Once all calibration pipelines are complete, we can calculate the physical color on the screen with multiple projectors, which allows us to design unusual visual expressions of shadows. Fragment Shadow system synthesizes a single image on the screen from multiple different projectors and when we occlude one of them, the other image becomes “perceptible” as a shadow. This makes our real shadow fragmented, textured and even immersed in the graphics.

Fragment Shadow image generation enables addition and subtraction operation of color on the projection screen. For example, it is possible to synthesize a uniform white plane or even arbitrary moving images from a completely different texture which we can see when we occlude one of them. As other remarkable expressions, it is possible to put our shadows in between the multiple layers of projection images, or even generate geometrically fragmented shadows from own body.

Fragment Shadow system hardware consists multiple (up to 16) projectors and a horizontal wide large flat white screen (up to 15m wide x 3m height), a Computer with GPU (AMD Radeon Pro WX9100).