Digitizing the Appearance of 3D Printing Materials Using a Spectrophotometer

Area of Science:

• Materials Science
• Optical Engineering
• Additive Manufacturing

Background:

• Conventional methods for 3D printed part appearance prediction are insufficient for translucent materials.
• Existing techniques using reflectance or transmittance fail to accurately capture the complex light interaction in translucent media.
• Accurate prediction of optical properties like scattering and absorption is crucial for translucent materials.

Purpose of the Study:

• To develop and validate a novel method for characterizing the scattering and absorption properties of translucent 3D printing materials.
• To enable accurate appearance prediction for 3D printed translucent objects.
• To compare the efficacy of Monte Carlo simulation versus an analytic radiative transfer model for property estimation.

Main Methods:

• Printing multiple thin slabs of translucent material with varying thicknesses.
• Utilizing a spectrophotometer to measure light interaction (reflectance and transmittance) across different sample thicknesses.
• Fitting a model to the measured data to estimate material-specific scattering and absorption coefficients.
• Comparing a Monte Carlo light transport simulation with a developed analytic model based on radiative transfer theory.

Main Results:

• The proposed method successfully estimates scattering and absorption properties for translucent materials.
• Both Monte Carlo simulation and the analytic model provide viable means for property estimation.
• The estimated optical properties enable accurate multispectral photo-rendering comparisons.

Conclusions:

• The developed technique effectively characterizes translucent materials for appearance prediction in 3D printing.
• The combination of multi-thickness sampling and modeling offers a robust solution for a previously challenging problem.
• This work advances the ability to predict and control the visual appearance of 3D printed translucent parts.