Created Wavefront obj to sdf converter, to make it easier to import complex obj models with many materials. See kitchen for example.

Fix in tinyobj, make sure material is initialized
Add fatihrmutfak kitchen model, for Virtual Reality and some research

data/kitchens/fatihrmutfak/part66.mtl

@@ -0,0 +1,12 @@
+# Blender MTL File: 'None'
+# Material Count: 1
+
+newmtl wire_115115115
+Ns 31.372549
+Ka 0.000000 0.000000 0.000000
+Kd 0.451000 0.451000 0.451000
+Ks 0.350000 0.350000 0.350000
+Ke 0.000000 0.000000 0.000000
+Ni 1.000000
+d 1.000000
+illum 2