I found if you exchange the skp file to a OBJ file ,it will also create a mtl file which describe the material,
such as the text below
Wavefront material file
Converted by the DEEP Exploration 2.1.12.1218
Right Hemisphere, LTD
newmtl inside
Ka 0.4 0.4 0.4
Kd 0.587609 0.587609 0.587609
Ks 0.071744 0.071744 0.071744
Ns 32
newmtl outside
Ka 0 0 0
Kd 1 1 1
Ks 0.384296 0.194061 0.174387
Ns 64
map_Kd cup.jpg
and below is the explanation of Ka,Kd,Ks,map_Kd
Ka：Ambient Color
Kd：Diffuser Color
Ks：Specular Color
Ns：Shininess
map_Kd：the picture of Diffuse
and I wanna know how to get these data?
and another question is whether there are some sdk which could support api to write into obj file and mtl file?
thanks for your help!