We predict the appearance of materials from their physical microstructure
The appearance of a material is largely determined by the microstructure of its surface and the particles beneath its surface. We construct mathematical models for predicting material appearance based on surface properties and particle content. We also investigate the challenges of fast and accurate rendering of material appearance. The goal is to interactively compute realistic images of real-world materials.
We propose a method for direct comparison of rendered images with a corresponding photograph in order to analyze the optical properties of physical objects and test the appropriateness of appearance models. To this end, we provide a practical method for aligning a known object and a point-like light source with the configuration observed in a photograph. Our method is based on projective transformation of object edges and silhouette matching in the image plane. To improve the similarity between rendered and photographed objects, we introduce models for spatially varying roughness and a model where the distribution of light transmitted by a rough surface influences direction-dependent subsurface scattering. Our goal is to support development toward progressive refinement of appearance models through quantitative validation.
The dataset can be used to evaluate rendering techniques or for inverse rendering. It consists of three different objects, from multiple different viewpoints with different light positions. Each image has a segmentation and the estimated camera pose and light source position are stored in a json file. This is accompanied by a triangle mesh of the object. Please cite if you use the data.
The image of the bunny along with the segmentation.
Images of the angel, shown with segmentations. Two camera poses and one light source position.
Images of the bust taken from four different camera positions, each with five different light source positions. Segmentations are also available.
@article{hannemose2020alignment,
title = {Alignment of rendered images with photographs for testing appearance models},
author = {Morten Hannemose and Mads Emil Brix Doest and Andrea Luongo and S{\o}ren Kimmer Schou Gregersen and Jakob Wilm and Jeppe Revall Frisvad},
journal = {Applied Optics},
year = {2020},
month = {October},
url = {https://people.compute.dtu.dk/jerf/papers/alignment_lowres.pdf},
}