Realistic Graphics Lab

Building Volumetric Appearance Models of Fabric Using Micro CT Imaging (ACM Research Highlight)

In Communications of the ACM (November 2014)

We build volu­met­ric ap­pear­ance mod­els of com­plex ma­ter­i­als like vel­vet us­ing CT ima­ging: (left) CT data gives scal­ar dens­ity over a small volume; (cen­ter) we ex­tract fiber ori­ent­a­tion (shown in false col­or) and tile lar­ger sur­faces; and (right) we match ap­pear­ance para­met­ers to pho­to­graphs to cre­ate a com­plete ap­pear­ance mod­el. Both fine de­tail and the char­ac­ter­ist­ic high­lights of vel­vet are re­pro­duced.


The ap­pear­ance of com­plex, thick ma­ter­i­als like tex­tiles is de­term­ined by their 3D struc­ture, and they are in­com­pletely de­scribed by sur­face re­flec­tion mod­els alone. While volume scat­ter­ing can pro­duce highly real­ist­ic im­ages of such ma­ter­i­als, cre­at­ing the re­quired volume dens­ity mod­els is dif­fi­cult. Pro­ced­ur­al ap­proaches re­quire sig­ni­fic­ant pro­gram­mer ef­fort and in­tu­ition to design spe­cialpur­pose al­gorithms for each ma­ter­i­al. Fur­ther, the res­ult­ing mod­els lack the visu­al com­plex­ity of real ma­ter­i­als with their nat­ur­ally-arising ir­reg­u­lar­it­ies.

This pa­per pro­poses a new ap­proach to ac­quir­ing volume mod­els, based on dens­ity data from X-ray com­puted tomo­graphy (CT) scans and ap­pear­ance data from pho­to­graphs un­der un­con­trolled il­lu­min­a­tion. To mod­el a ma­ter­i­al, a CT scan is made, res­ult­ing in a scal­ar dens­ity volume. This 3D data is pro­cessed to ex­tract ori­ent­a­tion in­form­a­tion and re­move noise. The res­ult­ing dens­ity and ori­ent­a­tion fields are used in an ap­pear­ance match­ing pro­ced­ure to define scat­ter­ing prop­er­ties in the volume that, when rendered, pro­duce im­ages with tex­ture stat­ist­ics that match the pho­to­graphs. As our res­ults show, this ap­proach can eas­ily pro­duce volume ap­pear­ance mod­els with ex­treme de­tail, and at lar­ger scales the dis­tinct­ive tex­tures and high­lights of a range of very dif­fer­ent fab­rics like sat­in and vel­vet emerge auto­mat­ic­ally—all based simply on hav­ing ac­cur­ate meso­scale geo­metry.



Text citation

Shuang Zhao, Wenzel Jakob, Steve Marschner, and Kavita Bala. 2014. Building Volumetric Appearance Models of Fabric Using Micro CT Imaging (ACM Research Highlight). In Communications of the ACM (November) 57(7). 98–105.

    author = {Shuang Zhao and Wenzel Jakob and Steve Marschner and Kavita Bala},
    title = {Building Volumetric Appearance Models of Fabric Using Micro CT Imaging (ACM Research Highlight)},
    journal = {Communications of the ACM},
    volume = {57},
    number = {7},
    pages = {98--105},
    year = {2014},
    month = nov,
    doi = {10.1145/2670517}