1 Charles University
2 University of California, Santa Cruz
3 Institute for Science and Technology Austria
4 Max Planck Institute for Informatics, Saarbrücken, Germany
5 University College London
Volumetric light transport is a pervasive physical phenomenon, and therefore its accurate simulation is important for a broad array of disciplines. While suitable mathematical models for computing the transport are now available, obtaining the necessary material parameters needed to drive such simulations is a challenging task: direct measurements of these parameters from material samples are seldom possible. Building on the inverse scattering paradigm, we present a novel measurement approach which indirectly infers the transport parameters from extrinsic observations of multiple-scattered radiance. The novelty of the proposed approach lies in replacing structured illumination with a structured reflector bonded to the sample, and a robust fitting procedure that largely compensates for potential systematic errors in the calibration of the setup. We show the feasibility of our approach by validating simulations of complex 3D compositions of the measured materials against physical prints, using photo-polymer resins. As presented in this paper, our technique yields colorspace data suitable for accurate appearance reproduction in the area of 3D printing. Beyond that, and without fundamental changes to the basic measurement methodology, it could equally well be used to obtain spectral measurements that are useful for other application areas.
Oskar Elek, Ran Zhang, Denis Sumin, Karol Myszkowski, Bernd Bickel, Alexander Wilkie, Jaroslav Křivánek, Tim Weyrich.
Optics Express, 29(5), pp. 7568–7588, February 2021.Oskar Elek, Ran Zhang, Denis Sumin, Karol Myszkowski, Bernd Bickel, Alexander Wilkie, Jaroslav Křivánek, and Tim Weyrich. Robust and practical measurement of volume transport parameters in solid photo-polymer materials for 3d printing. Optics Express, 29(5):7568–7588, February 2021.Elek, O., Zhang, R., Sumin, D., Myszkowski, K., Bickel, B., Wilkie, A., Křivánek, J., and Weyrich, T. 2021. Robust and practical measurement of volume transport parameters in solid photo-polymer materials for 3d printing. Optics Express 29, 5 (Feb.), 7568–7588.O. Elek, R. Zhang, D. Sumin, K. Myszkowski, B. Bickel, A. Wilkie, J. Křivánek, and T. Weyrich, “Robust and practical measurement of volume transport parameters in solid photo-polymer materials for 3d printing,” Optics Express, vol. 29, no. 5, pp. 7568–7588, Feb. 2021.
This project has received funding from the European Union's Horizon 2020 research and innovation program, under the Marie Skłodowska-Curie grant agreement No. 642841 (DISTRO), and under the European Research Council grant agreement No 715767 (MATERIALIZABLE). It was further supported by the Czech Science Foundation grants 16-18964S and 16-08111S, the Charles University grant SVV-2017-260452, and the Engineering and Physical Sciences Research Council grant EP/K023578/1. We are grateful to Stratasys Ltd. for access to the voxel-level print interface of the J750 machine.