Fig. 1. BRDF measurement principle

Fig. 2. Overall structure diagram of reflective light field measurement system

Fig. 3. Mathematical model of aspheric mirror

Fig. 4. Structural light path diagram of catadioptric panoramic imaging optical system

Fig. 5. Modulation transfer function curve

Fig. 6. Spot diagrams

Fig. 7. Simulated light array model of field angle resolution

Fig. 8. Angle distribution diagram of lamp array arrangement

Fig. 9. Illumination distribution map of angle resolution analogue image surface

Fig. 10. Off-axis spatial position mapping model

Fig. 11. Coordinate distribution of feature points after calibration

Fig. 12. Illumination distribution of image surface measured by Lambert light field

Fig. 13. Illumination distribution of image plane of Lambert light field after calibration

Fig. 14. Relative error of the circumference range under each zenith angle

Fig. 15. Measurement model of multi-angle reflected light field on rough surface

Fig. 16. Light intensity distribution of reflected light field from three rough surfaces. (a) Labsphere Permaflect-80 diffuse reflector; (b) WhiteOptics-DF60 diffuse reflector; (c) mirror aluminum plate

Fig. 17. BRDF curve of three kinds of rough surfaces in the incident plane. (a) Labsphere Permaflect-80 diffuse reflector; (b) WhiteOptics-DF60 diffuse reflector; (c) mirror aluminum plate