There were a few bugs that was causing issues with metallic materials. I never tested any metallic material so thanks for report.
I think you were looking for something like this but this will look much better once real environment reflections be there.
I used these material parameters:
{
"name" : "Cessna_EXT-material",
"diffuse" : "0.025,0.025,0.025,1.0",
"Ax" : "0.91",
"Ay" : "0.04",
"m" : "0.15",
"tex_diffuse" : "",
"tex_normal" : "",
"tex_env" : "",
"tex_opacity" : ""
},
- diffuse has to be very low or zero because metals don't have diffuse only reflections and diffuse reflection is usually caused by corrosion or impurities...
- Ax is reflectance and for usual material it should be in range 0.01-0.04 glass has ~0.08 and metals 0.3+
- Ay is not used so all our materials are isotropic, (performance reasons but may be i will implemented it later)
- m is surface roughness 0 means perfect mirror and 1 means mate material
It is possible to set Ax and m parameters through textures but this feature is not enabled yet. This will allow you to have more variations without raising draw calls count. In most cases texture with m is enough, it is similar to specular in alpha channel used in other engines but this parameter is more physically accurate.