Export Obj and Three.js

To improve the graphic rendering of an obj exported from eyeshot in a web application that uses Three.js you should add the following fields in the material definition

Bump as string        bump map image

bm as double          bump multiplier

norm as string         normal map (RGB components represent XYZ components of the surface normal)

ke as color              Emissive using RGB values

ns as integer           The specular exponent (defines the focus of the specular highlight)  [0-1000]

d or Tr                     transparance

and export it in the definition of mtl file.

For the reading parameters from mtl file with three.js library see this https://github.com/mrdoob/three.js/blob/7830fe3423d042b3735498adf2e1c49d0631442c/examples/jsm/loaders/MTLLoader.js#L507-L514